View Full Version : How to kill your Opti or don't do this


sbca96
08-30-2012, 02:43:41 AM
Yup ... it looks like it happened, and its ALL my fault, first from touting too often
here that the opti failures are over blown (tempting fate) & second by pressure
washing my Impala SS engine after dousing it with simple green. I have done it
in the past a number of times without issue, BUT, this time while I was doing it I
heard a "snap" sound (like a bolt breaking) and thought : 'that was weird'. So I
fire it up, and drove to the store .. when I got there I see a lot of steam coming
out from under the hood and again thought 'weird'. I looked under the car and I
see a puddle .. thats not good. Pop the hood and I see coolant spraying in the
firewall on the passenger side. I limp home and shut it down.

Inspection found the steam crossover tube popped ('snap' I heard) and that did
in my chance to drive the car and cook off excess water. Car sat for a week or
so as I ordered a new steam tube from Scoggin Dickeys (80 something shipped).
I put it back together and it fired up and ran GREAT! All was well and I put it in
the street with plans to drive it in a couple days to work......

Went to fire it up in the morning a few days later and it fired SLOW, grumbled &
died. Tried again and it ran at about 300 rpm - died. Tried again and this time
it wouldnt start. If I held the pedal to the floor it would fire and die. Later that
evening I checked fuel pressure : 38-40 PSI, swapped out the ICM/Coil from the
78 Camaro project, and put in an EGR I had laying around. Nadda. I can smell
fuel VERY strong under the hood, so I have to assume its the Opti. I am sure as
Aceshigh reads this he is laughing his ass off, and I dont blame him. What sucks
is this is a vented opti (1995 Impala SS) and ironically its also the ONLY car I've
had an opti fail on (the one I quote as had driven home 55 miles after failure). I
set myself up for this .. got WAY too cocky and apparently lucky in that I have
always driven the car a good distance after a cleaning the engine (must work!).

So I checked around, seems since Dal retired GM Performance Optis are that of
the rich, not going to put a Accel electrical part on my car again, MSD is quite a
lot just because its red, and a reman spells trouble in my book.

I ended up ordering a Cardone Select, they claim they have re-engineered it and
fixed OEM mistakes, its also NEW, not a reman, and its a lifetime warranty. The
best part is : Rockauto has it for $164 dollars! With a discount code it was $164
shipped to my door. Not bad. Should be the "last" opti I buy for this car. I almost
bought one for the '78 Camaro too, but I will hold off for now - I have one from
my 1993 Camaro Z28 that WASNT bad (was a bad Accel coil that time).

http://www.cardone.com/Products/Product-Detail?productId=841833

Tom

Aceshigh
08-30-2012, 04:09:51 AM
Yup ... it looks like it happened, and its ALL my fault, first from touting too often
here that the opti failures are over blown (tempting fate) & second by pressure
washing my Impala SS engine after dousing it with simple green.

http://i46.photobucket.com/albums/f122/Aceshigh22/vincent-price-o-rly.gif

Sorry to hear that Tom.
Hope ya get it fixed up quick.

I've always said your good fortune has alot to do with your moderate year round California weather.
Less moderate areas aren't as fortunate with those Opti's.

danbrennan
08-30-2012, 09:24:05 AM
Interesting. I saved this, some good notes about symptoms. I have a '96 Impala SS, and a '95 Formula, with LT1s. So far so good on the optispark units, although I bought the Formula used, so I don't know if it got replaced at one time or another.

sbca96
08-30-2012, 12:34:11 PM
I've always said your good fortune has alot to do with your moderate year round California weather.
Less moderate areas aren't as fortunate with those Opti's.

Thats probably a factor, though I live near the ocean with lots of fog, so its a
damp climate. I dont see the opti getting road water on it even in severe rain
but there is no way to be 100% sure. I think it was the lack of a long drive to
burn off the water, also after typing this, I think the steam under the hood may
have been the death push. When the steam line broke it was pretty intense. I
actually THOUGHT the car was on fire!

Interesting. I saved this, some good notes about symptoms. I have a '96 Impala SS, and a '95 Formula, with LT1s. So far so good on the optispark units, although I bought the Formula used, so I don't know if it got replaced at one time or another.

Yup, I had one fail (on this car) at 170k (or so) and now this one I killed at the
230k (or so) mark. I had the water pump fail on two cars without taking out an
Opti ... but perhaps I needed a reminder to be more careful. That steam line
was a ticking timebomb ... the cooler water made a weak spot let go.

Tom

camarochevy1970
08-30-2012, 02:42:00 PM
The part that is going to suck, is that no aftermarket unit is going to last as long now

sbca96
08-30-2012, 05:16:33 PM
The part that is going to suck, is that no aftermarket unit is going to last as long now

Perhaps, its hard to say really. Keep in mind that Moog makes aftermarket
and they are leaps better quality then OEM. Its POSSIBLE for an aftermarket
company to better GM. There are also a lot of cheap ones (a search found a
few that claimed to be the CHEAPEST Opti available - not exactly what I want
when there is more to swapping it then yanking an HEI.)

I wrote this thread on the Impala forum for changing out the seals, I wont be
doing that this time around, but there is good info here.

http://www.impalaclub.com/naisso/Forum2009/topic.asp?TOPIC_ID=30984

This thread has 88,000 views .... imagine if everyone that read it gave me a
dollar for my trouble ..... hmmmm. Imagine that ....

Tom

sbca96
08-30-2012, 05:17:17 PM
Fed Ex says it will be on my front porch tomorrow. Rockauto = fast service!

Tom

drptop70ss
08-31-2012, 08:06:39 PM
I never pressure wash any late model engine, for all you know you only got water inside the connector of the opti harness, the rubber seals do dry out and then the connections can corrode. I cant see anyone power washing an LS1 either, I certainly wouldnt. Simple green and a wipe off is all I will do. Did you scan for codes for the resolution loss? They can be thrown and not set off the SES.

rwild1967
08-31-2012, 08:16:39 PM
Thats a darn good price on a new unit. Last one i bought for my 95 z was over $ 400.

sbca96
08-31-2012, 08:30:10 PM
I never pressure wash any late model engine, for all you know you only got water inside the connector of the opti harness, the rubber seals do dry out and then the connections can corrode. I cant see anyone power washing an LS1 either, I certainly wouldnt. Simple green and a wipe off is all I will do. Did you scan for codes for the resolution loss? They can be thrown and not set off the SES.

There were no Opti codes stored. I scanned with two scanners. The only one
I saw were a fan 1/fan 2 error which I assumed was from the aftermarket fan
controller I installed (Jet I believe) because the fans didnt come on until it was
into the red and that freaked me out. Now that I have tuning software I have
been thinking about re-programming the PCM like I did the '78's LT1 PCM.

I dont THINK its water in the connector, unless its corrosion that I got from it
sitting for a week? I will pop off the connectors and look for any before I yank
the opti. I figured the price was low enough it was worth the risk, I needed to
have it BEFORE the 3 day weekend and since the car is in the STREET I need to
get it running ASAP (literally couldnt wait to diagnose the opti further).

I had to do a "leap of faith" that Aceshigh is right.;)

Tom

sbca96
08-31-2012, 08:45:18 PM
Thats a darn good price on a new unit. Last one i bought for my 95 z was over $ 400.

Agreed. The one I almost bought was a Jegs brand (might be the same unit)
that listed for $249, but was on "special" for $199. With an item like this I'm
more prone to go OEM, but seeing it online for $700 bucks for new? No way!

Then GM offers a REMAN for just shy of $400 bucks.

This reminds me of the conversion I had with a GM Dealership years ago ....
I wanted to buy a NEW torque converter, they were still making 4th Gens.

"I need a torque converter for a 1993 Camaro Z28" - Me

"We have a REMAN listed for 400 dollars." - Parts

"How much is a NEW one?" - Me

"There is no new one available" - Parts

"What do you put in NEW Camaros?" - Me

"They get new torque converters" - Parts

"Ok, I want one of those" - Me

"Sorry, we can not sell those to the public" - Parts

:rolleyes:

Tom

drptop70ss
08-31-2012, 10:27:19 PM
Without a low or high resolution code fault I do not know why it would be the opti, this is why the thing has such a bad reputation. There are guides on the net on how to troubleshoot and test the opti to help. I have only had one opti failure out of dozens of engines, was a 94 F body unvented unit. Would intermittantly store a code for loss of the high resolution pulse. I have not had a failure with a vented unit so far. You should find someone that is hands on smart and not book smart for helping diagnose the issue, shbox and injuneer over at camaroz28.com are a couple of the best. If this were a standard SB chevy and you hit it with a hose you would be looking for water in the cap or wires causing the misfires, if the optical sensor is ok you may just have to take the opti apart and dry it out. Use RTV when you put the cap back on. I will always keep a GM opti over any aftermarket unit.

sbca96
09-01-2012, 04:31:20 PM
Thanks. I found the trouble shooting info on shbox page, I was going to print it
and go through the steps, but I was running out of time. I figured it was best to
have the opti on hand if it turns out to be bad.

I had planned to "Check" the results before putting the WP back on and coolant
in. You can start them with just the opti on to make sure it was the problem.

What's funny, I have never had a non-vented opti fail .....

Tom

sbca96
09-02-2012, 12:13:51 AM
The voltages checked out, there was a pulse showing on pin "B" of 1.9 or so AC
volts. Got 11.8 DC volts on pin "A" and pin "D". Removed the opti harness (the
damn clip broke, I have another one somewhere) and found greenish goo on the
bottom of the connector and down inside the plug. I cleaned it out, and it did
the same thing - fire slowly, run a few seconds at ultra low RPM and die. It gets
worse the more you try until it only sputters at first crank.

So apart it went. I disassembled the Opti as suggested and found wetness at
the connector and on the sensor, also signs it has splattered around inside. It is
like oil actually and the bearing sounds odd when you spin it. It also wobble lots
and I wonder if the bearing failed and spewed its lubricant inside the opti.

That said the metal plate inside had rust on it and there are other signs its not
up to par. I am going to assume its bad. Should there be very noticeable play
in the bearing? I can see the disc wobble inside the optic sensor.

Tom

sbca96
09-02-2012, 12:19:35 AM
For the record the tests are here :

http://shbox.com/1/4th_gen_tech2.html#opti_test

Disconnect the ICM connector. Leave coil connected (important).

Turn key to ON.

Check for dc voltage with a digital meter at harness terminal "A" to ground and and also "D" to ground. Note: Use a modern digital meter with at least 10 megohm impedance to protect the PCM (in case you measure anything in that direction). Also make sure your meter leads make good contact and are clean and tight. Check that you get a zero ohms reading by touching the two leads together. That will ensure accurate resistance readings

Result should be 10v dc or more on the A and D terminals. If you get no voltage, use the diagram and chase back toward the coil and the ignition fuse. Power for the ICM comes from the ignition fuse and through the coil, so any of that could be bad.
If you have good voltage, switch the meter to ac scale and connect test leads to terminal "B" and to ground. Observe meter while cranking the engine. You should see between 1 and 4 volts ac (those are the pulses that trigger the coil to fire).

If you don't see the proper ac voltage the problem could be the optispark, the harness to the optispark, the PCM (not common) or any of the wiring in between. Visually inspect all the connections for possible poor contact or corrosion.

You should also check "C" of the ICM harness for continuity to ground.

Fbird
09-02-2012, 07:55:43 AM
that suks. I don't know jack about the Opti-spark systems (pontiac didn't make a LT anything...lol ) but a very informative read. Hell I just know FULLY understand wtf the HEI module REALLY does and HOW it does it :eek: been using them for 30 yrs...

drptop70ss
09-02-2012, 09:48:49 AM
First off it still may or may not be the opti, really need to look at all engine sensor inputs after all that water getting on the engine. As far as the opti it sounds like the optical sensor may still be good but the water made a mess of things in there. The bearing may or may not be bad, cant tell over the internet. There will be some play but not a ton, should spin freely. As you know water and electricity do not mix, pressure washing is not a great idea and I would use RTV on the next opti cap you install and use some dielectric grease at the opti connection to prevent corrosion. I have seen the opti harness pins disintergrate from the green slime corrosion so hopefully your opti harness is still good. IMO the biggest issue with the opti is the location, nobody would ever run a traditional SB 150000+ miles without ever touching the cap and rotor but it happens all the time with the opti. First time it gets open it looks like hell because it has never been serviced.

sbca96
09-02-2012, 04:13:07 PM
I fully agree, the first one lasted 170k miles, the second one only about 70k. The
cap and rotor look good. I guess I can take the new opti from the box and see
if it has the same amount of play. The grease inside has me thinking its the opti
not something else. I swapped out the major parts that cause trouble with some
"known good". I have the opti harness from the Painless harness left over. But I
checked the original harness for continuity and everything checks out.

May or may not be the opti is certainly fact, perhaps with a scope its possible to
diagnose it 100% before swapping it out, but at home I think at this point the way
to find out is to put on the new part.

I think I will hold onto the old one (another reason I bought new - no core) and
research the bearing. Honestly the way it feels I can not imagine reinstalling it
unless I replaced the bearing. When I spin it fast I can hear a noise.

Tom

spinmaster
09-02-2012, 09:58:00 PM
Here is a tip I learned the hard way with my 95 Impala SS.
Quit using Dex-cool.
My water pump took a dump and Dex-Cool will make the seal on the Opti-spark unit swell and then Dex-Cool will take out the exciter wheel and fog up the Photo cell in the opti.
I replaced my water pump with 6 brand new water pumps and each one crapped out in a few weeks to a few months.
I ended up finding out the Dex-cool would atack the seals in the new water pumps and cause the pump to leak at the weep hole and this would let Dex-cool drop right on top of mt brand new Opti and swell the silicone seal around the cap of the opti.
I ended up getting another water pump and new Opti unit and I bought a MSD cap with a rubber seal and it comes with a extra bolt and clamp that will hold the cap in the top drivers side of the opti spark unit. I went ahead and drilled out the stock Torex screws and taped the hold out so you can now use a 1/4-20 screw and this will make the cap seal much better and you wont have to worry about striping out the bolts holes with the stock screws.
I then flushed out he whole Cooling system and installed Green Antifreeze and I have yet to have a single problem after I done this change over.
I can take my car to a car wash and drive over the under body sprayer and drive threw standing water and not one problem with my Opti.

sbca96
09-02-2012, 11:00:10 PM
Good info Spinmaster, I am pretty sure my Impala has the green stuff, though in
all honesty its actually rust colored from neglect.

Took the new opti out of the box and checked the bearing play : there isnt any.
This was good news. I put the opti on and hooked up everything that HAD to be
hooked up and turned the key : Crank, crank .. VROOOOOM!

Fans came on instantly .. but thats normal with no temp sensor.

So for the record : the opti bearing failed .. looks like it was totally coincidental.

For those checking the new opti before re-assembling everything .. I put on the
opti, wires, coil wire, plug to harness and front pulley. No intake, water pump or
AIR pump. Like I said .. it WILL fire (usually taking an extra crank).

Also .. an added bonus : the Cardone comes with a NEW opti harness!! Down
side was it had an extra tab inside my harness didnt have, but an Xacto made
short work of it and it plugged right in.

Tomorrow the serpentine belt, a couple hose clamps and coolant. While it was
off I went ahead and warrantied the Autozone water pump, figured no sense
in putting a used water pump back on.

Tom

arick793
09-03-2012, 01:03:41 AM
This thread has 88,000 views .... imagine if everyone that read it gave me a
dollar for my trouble ..... hmmmm. Imagine that ....

Tom

There are actually forums like that. I've found them in my internet travels. Or there's a box that pops up and says "ask a chrysler mechanic! 24 of them are online right now!" It's really not a bad idea. Usually you post your question, and a mechanic offers an answer, along with a "price tag", and if you like it then you pay the man. It's kind of integrity based, but it works. People try a little bit harder to help when they're getting paid too. Lawyers do this a lot over the internet, but they're a little more careful (because they're blood sucking lawyers) and wait until you pay them to answer the question. It still beats the $250 an hour I pay my guy. Guys do this on youtube too, once you get over a certain number of views on your video, it gets sponser attention, and you get paid. Hell I bet olstyle can make some money on this website, because his prpjects are so damn addicting to watch that everyone wants a part! Anyway I'm glad you got the motor going! I was hoping you'd do the LS1 computer and coil conversion though ;)

drptop70ss
09-03-2012, 11:50:26 AM
Glad you got it fixed, now it will be a good test to see how good the cardone opti is. I still think the power washing did it in, I wouldnt think the bearing would be a killer unless the rotor hit the cap.

sbca96
09-03-2012, 08:03:13 PM
OK. I am at a loss here.

Hooked everything back up the way its SUPPOSED to be and it wont run.
It would sputter and die. I literally stared in complete disbelief.......

If you had ANY idea of the hell I had to go through to fix this thing (out in the
street because it wouldnt start) you would be as annoyed as I am now. I have
a psychotic next door neighbor thats harassed my wife & I for about 3 years
now. He has assaulted my dad and I (72 years old at the time), called us every
name in the book, threatened bodily harm, made racial slurs, screamed sexual
comments at my wife, made fun of the fact we cant have kids, and tried to get
me to fight him in the street. Because this is California .. the Police do nothing.

While I was out there with the engine open, he was at the corner of his front
yard with his weed wacker purposely aiming debris at me and the engine. This
is what he did to my dad and I when we were trying to mark off posts to build
a fence to keep his drunk arse out of our front yard. He put the business end
of the weed wacker about 12 inches from my face and accused me of being on
his property (an out-right lie we were on MY side of marker HIS surveyor put
into the ground). I told him to call the Police and he threatened me and put
the blade into the ground in front of my face. When I could see again I got my
dad to safety and called Police. A week before he had been told by Police that
if he did ANYTHING toward us he would be arrested. They showed up, told me
to grow up and left. He ended up in Court due to trying to get me to fight in
the street (which apparently is the ONLY Law they would go after him for). It
was a Misdemeanor, but he pleaded it down to an Infraction (he would have
lost his license to do what he does for a living if it were more).

Here we are a year later and he still feels its OK to do this..... rant over.

So ... I disconnected the MAF and the temp sensor and the engine runs.

WHY????

Tom

sbca96
09-03-2012, 11:47:01 PM
Things done so far :

Cleaned MAF : nadda

Removed air filters (to clean - they are drying now).

It will NOT run with the MAF AND the temp sensor hooked up. Unplugged it fires
up after the usual extra cranks and then idles out just fine. Fans start up and it
continues to run. When plugged in, the engine fires strong and dies. Second try
it sputters and dies. Third try you can smell strong fuel odor.

Hate to break it to you Aceshigh .. it WASNT the Opti. This is the second time
I have replaced an opti that wasnt bad because of the fear mongers. At least
this time I feel the bearing was going to cause trouble soon.

At least I was able to put it into the driveway and out of view of the psycho. It
is a little easier to diagnose things when you don't feel there is a gun trained on
your head.

Tom

77nomad
09-03-2012, 11:50:41 PM
Can we get some of our Cali members over there to have a "talk" with your neighbor. I swear I would help you out if I were anywhere close. And don't even know you. This guy sounds insane. I would at least call ALL my hotrod buddies over for a tuning party during a weekend when he has company. 4-5 SBC's all running 3g to set the timing all day will surely get under his skin.

sbca96
09-04-2012, 01:34:37 AM
This guy sounds insane.

He is definitely insane. If you heard half the bizarre stuff he was yelling at my
wife & I you would be shocked. Yet the Police say he can: freedom of speech?

He said to me early on he was going to make my life hell because I never waved
to him. He told me he was going to own the neighborhood and my rein was over.
After we built the fence between our front yard and his, he repositioned his lawn
sprinklers to constantly wet my fence. He also changed the landscaping so the
posts sit in water. Since my yard is now lower there isnt anything I can do. The
HOA refuses to help me, even though the Rules clearly state he can not do a
change like this without a Board of Review for negative effects.

That said ... anyone have any idea why the car wont run with the MAF and the
temp sensor hooked up?

Tom

drptop70ss
09-04-2012, 09:12:07 AM
MAF or temp sensor is probably toast from the power washing or the wiring is wet, but like I said earlier you need to scan the engine sensors ( a real time scanner, not a cheap code reader) and see what they are reading to troubleshoot the problem. Temp sensor on the water pump is for the PCM, with a scanner you can see what it is reading, could be telling the engine that it is freezing out and dumping fuel (for example). Fix one issue at a time but get or borrow a good scanner. I had one LT1 that would just sputter and die, previous owner had swapped till you drop with just about everything in the engine. MAP sensor readings were crazy high, turned out to be a collapsed cat converter.
Go for the MAF first if you can get one to swap in and do not have a scanner, it is common for an engine to run with the MAF disconnected if it has a problem.

sbca96
09-04-2012, 12:19:27 PM
MAF or temp sensor is probably toast from the power washing or the wiring is wet, but like I said earlier you need to scan the engine sensors ( a real time scanner, not a cheap code reader) and see what they are reading to troubleshoot the problem.

Agreed. I have a VERY nice, rather expensive real time Actron scan tool, it is
an AutoXRay 3000 and allows you to watch what everything is doing ....

http://www.readerobd.com/wp-content/uploads/aes/OBD-II-Scan-Tools_351.jpg

Except on this car, it has never read this PCM. This is my luck guys.:mad:

To read the fan 1/fan 2 fault code that was stored, I borrowed my non-crazy
neighbors scan tool that does both OBD1 and OBD2.

I guess I can borrow back his scanner and see if it does real time ... BUT the
problem is .. the car WONT start with the sensors hooked up. It also will not
start if I just hook the temp sensor back up. Both have to be unplugged....

Tom

drptop70ss
09-04-2012, 01:18:54 PM
I have a similar AutoXray but it does OBDI and OBDII, has worked great for me. The car doesnt have to be running to scan, just key on. You want to see the sensor output readings to the PCM. Coolant temp should be ambient and the MAF should have a reading range, dont know it off the top of my head but you should be able to find what the voltage range is online.

sbca96
09-04-2012, 05:21:03 PM
I have a similar AutoXray but it does OBDI and OBDII, has worked great for me. The car doesnt have to be running to scan, just key on.

Yup. I know. I have read the 1994 PCM in the 78 Camaro many times and it
worked perfect with the 1993 PCM .. but it has never worked with the 1995. I
will look at the pinouts tonight and see if they swapped the data lead over to
the OBD2-ish location. I can try the MAF from the 78 Camaro.

Neighbor says his only reads codes .. no real time.:mad:

I need to get my scan tool to work - somehow. I gets in an error and says it
is "not responding". Keep in mind it did this for years.

Because of all that hot coolant coming off the back of the engine, you think it
could have shorted the passenger side O2 sensor? From what I read, if you
disconnect the MAF it forces it into open loop SD programming. So it doesnt
use the O2 sensors. I am temped to disconnect the O2 sensor and reconnect
the MAF and temp sensor and see if it fires.....

To add insult to injury a bolt broke off on my 2004 GTO B&M shifter and so it
is dead in the driveway. When it rains it pours. I got new screws but I used
loctite and its a stainless steel bolt.

Tom

drptop70ss
09-04-2012, 05:54:59 PM
First off keep in mind that 1995 is OBD1 but uses and OBDII style connector, there is a special cable just for that setup.
As far as the 02 sensor, with the scanner running you can easily see the mV readings for them, so get the scanner running first. Swap to you drop is not the way to go, and the o2 sensors do not even come into play at any time until the engine is over 160 degrees and goes into closed loop (another thing you will be able to check once the scanner is working).

sbca96
09-05-2012, 12:45:59 AM
First off keep in mind that 1995 is OBD1 but uses and OBDII style connector, there is a special cable just for that setup.
As far as the 02 sensor, with the scanner running you can easily see the mV readings for them, so get the scanner running first. Swap to you drop is not the way to go, and the o2 sensors do not even come into play at any time until the engine is over 160 degrees and goes into closed loop (another thing you will be able to check once the scanner is working).

I wasnt going to purchase anything more, just figured if it was shorted ....

This car actually has the OBD1 connector and yes its OBD1. I dont know why it
refuses to scan, it did start life as a 9C1, but why would that matter?

I went to try the MAF from the 78 Camaro on the Impala and good news! Its not
the same diameter! Oh wait .. thats not good news. So that idea went poof.

I have been offered up a laptop/cable and TTS Datamaster software. What I
worry about it if the scan tool cant scan it, will the laptop be able to?

Tom

drptop70ss
09-05-2012, 08:18:31 AM
Yours must be different, 95 was a crossover year and a lot of the cars have OBDII connectors, I have a special cable just for it. Double check your connector on the car and see if the wiring diagrams match up with your cable that you are using. I think the data wire is tan with a white stripe. Also on some cars like the camaro the power for the data link is run through the cigarette lighter fuse, blow that fuse and no communication.

sbca96
09-05-2012, 12:22:11 PM
Yah, we had a 1995 Camaro Z28 that had the OBD2 connector with OBD1. I
actually bought this scan tool for that car because it came with the OBD2 as
well as OBD1 cables. The Impala definately has an OBD1 port, I will compare
it to the 78 Camaro Painless port to make sure the leads are in the right spot.

I know that car reads fine.

Impala/Caprice was also different in that it only came with the vented opti. It
was on the leading edge for that (in 1994), the Camaro didnt see the vented
opti until 1995.

Tom

drptop70ss
09-05-2012, 12:44:20 PM
Good luck hope you can get it to read, and check those fuses.
I know all about the caprice / roadmaster differences, I kept a bunch of iron head LT1s here from 94-95 caprice wagons and 9C1 police cars that I parted out over the last few years. Still have a very nice 94 roadmaster wagone here with 92K miles on it, old man car I picked up for $600, too cheap to pass up, cant make myself cut it up yet.

sbca96
09-05-2012, 05:25:23 PM
Good luck hope you can get it to read, and check those fuses.
I know all about the caprice / roadmaster differences, I kept a bunch of iron head LT1s here from 94-95 caprice wagons and 9C1 police cars that I parted out over the last few years. Still have a very nice 94 roadmaster wagone here with 92K miles on it, old man car I picked up for $600, too cheap to pass up, cant make myself cut it up yet.

Those Roadmasters make nice Impala SS wagons. Blacked out with radiused
rear wheel openings they look like badazz hearses. Or make an El Camino...

Tom

drptop70ss
09-05-2012, 09:57:51 PM
Plans were to make it into a hearse for Halloween but got a real one instead. :cool: Almost time to scare the kiddies!

http://i34.photobucket.com/albums/d136/drptop70ss/018.jpg

sbca96
09-09-2012, 11:37:49 PM
Very weird. My neighbor thought to check his daughters 4 banger S10 and sure
enough it was the same size as the B-body MAF. I figured it was worth a try. I
swapped it out, hooked everything up and to my complete amazement it fired up
after a little hesitation but ran fine. Each try after it fired right up. I hooked up
the datamaster PC and ran a logging. I watched as it went into closed loop.

I honestly dont get it. A bad MAF should still run .. it will go into MAP right??

WHY did it have to have the coolant temp sensor also disconnected? That one
is really strange. It was reading temp, something like 60 degrees C?

I guess I need a MAF .. checking prices now. Since I have to change it anyway
I am tempted to go with an F-body MAF instead and get a new air filter.

Tom

drptop70ss
09-10-2012, 08:19:49 AM
Not sure why the coolant temp needed to be disconnected, would have to see what it read with the old MAF. When the MAF fails the engine will do what yours did, start and shut off or start and run barely with a lot of throttle, then die when you let off.
If you change to the F body MAF I believe you have to make changes to some tables in the PCM, I would just stick with the B body part and drive it.
Glad you got it fixed, at least you know now not to jump to the opti without an opti related code.

sbca96
09-10-2012, 12:14:31 PM
Glad you got it fixed, at least you know now not to jump to the opti without an opti related code.

Not fixed, since I had to give the MAF back. Keep in mind I didnt have a MAF
code either. Only codes were Fan1/Fan2. To find out the MAF was "bad" the
action was replacing it (just like I did with the opti).

I know what you mean, but so far the PCM isnt helping diagnose anything. It
should run with just the MAF disconnected, the fact the coolant sensor has to
be disconnected too makes me wonder if something else is actually wrong. I
dont see how the symptoms would have pointed to the MAF, the way it spins
backward and sputters like its misfiring point to distributor-related.

I swapped out the parts with known-good (relating to the symptoms) before
I changed the opti. Heck, I even took the opti apart and found questionable
conditions before putting the new one on. Hindsight makes me wish I had
disconnected the MAF and coolant sensor prior to removing anything, I just do
not see how I would have come to that solution.

Do you have TTS Datamaster? I can send you the attempted start with the
"bad" MAF and the running with "good" MAF files to look at.

Tom

drptop70ss
09-10-2012, 01:27:31 PM
I do not have the datamaster, so far scanning data with my xray has been enough for me to troubleshoot issues. You have to remember the car only sets a code if the sensor inputs are out of range, you can have sensor problems and not set a code, which is why you have to look at sensor input data to troubleshoot and not do the "swap to you drop" thing. There are plenty of things that can be checked with a DVM and not even use the scanner if not available. Coolant temp sensor for the PCM can be tested with a DVM if you cant get the scanner to work.

sbca96
09-10-2012, 05:17:04 PM
I do not have the datamaster, so far scanning data with my xray has been enough for me to troubleshoot issues. You have to remember the car only sets a code if the sensor inputs are out of range, you can have sensor problems and not set a code.

Good points, well I guess no matter how much you know, there is still more.
It is worth stating again ... it wasnt the optispark AcesHigh!

I fell victim to the hype and I am outspoken against it! Go figure.

Tom

sbca96
09-11-2012, 12:22:49 PM
So my friend looked through the datascan and found a "ton of codes" so I did
a scan with my neighbors AutoXRay and found 3 codes :

1. coolant temp low #15 (makes sense with the sensor being unplugged)

2. spark timing #41 (obvious misfire with bad maf connected)

3. MAF failure #48 (makes sense with the sensor being unplugged)

Thats all. Cleared codes and put on the neighbors MAF. I ran a second scan
and it found no codes. It went into closed loop and everything looks good.

When I did the scan prior to swapping the opti I only got Fan1/Fan2. I think
all these codes were set from running the engine without pieces hooked up.

Tom