I have a 79 z with a 350 4sp, car was hesitiating, my mechanic found oil in distributor, replaced distributor, cap wires plugs, re-timed, now car gets to 3000 rpm and bogs down no power, car has new timing chain distributor cap wires plugs fuel pump, changed carb to test still bad, can't get car to run unless time is advanced way up, then backfires thru exhaust on deceleration any help would be great

Was it this screwed up BEFORE they did anything to the timing chain ???

car ran well just had a slight sputter when cruising, that is when the distributor was changed with the wires plugs and cap, this is when the car would not run past 3000 rpm, that is when i put a new chain in it, no change,

What did your mechanic set your total timing at? Just about any mild 350 Vac advance unplugged should be around 36-38 by 3000 that would be ballpark, if its off you lose alot of power. The backfiring is probrably a carb adjustment, I remember when I was a teenager Id richen my Idle mixture on my old Q-Jet and it would "pop-pop-pop" not backfire on deceleration?

[This message has been edited by Mwilson (edited September 20, 2005).]

Does this car have Catalytic Converters?

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no cats on car, the car ran ok until the distributor was installed now it has no power at 3000 rpm and above,

Check your timing and make sure your distributor is advancing. As Mwilson said you want about 36 degrees of advance total with the vacuum advance disconnected.

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1980 Z28 a work in progress!

How is this done, i have only timed it at idle with a light and the timing is 6 degrees btdc, Ken

just wondering ig anyone else had some thoughts

Timing looks to be your main prob.

To check total timing you will need 1 of the 3

1) A dail back timing light
2) A degreed damper and reg. light
3) A timing tape and reg. light.

Hook up timing light, unhook and plug dist. vac line, crank engine

If your useing a dail back light, have a buddy to rev engine up to 3,000 rpm and shoot light at damper, turn knob on back of gun or push button on gun till the mark on damper lines up with the 0 (TDC) line on tab.

Now read what number the dail on your gun is setting on. That's your total timing.

If your useing a degreed damper or timing tape. Just bring engine to 3,000 rpm and shoot gun at damper. Line up the 0 (TDC) mark on tab with what ever number on the tape it points to and thats your total timing.

I would check at many rpm's to get your full curve.

Idle, 800, 1000, 1500, 2000, 2500, 2800, 3000, 3200, 3400.

You want full amount of timing at 2800-3200 rpm depening on combo.. Gen. is 3,000 rpm

If it keeps advancing past 3,000 rpm then you need to re curve your dist. (add a lighter spring)

But untill you get a dail back light I would say adjust timing at idle to 8-14*

Try 8, 10, 12, 14 and see how it feels, and listen for any detonation (ping) under part throttle and full throttle on the road.

Most HEI's will take about 12* at idle to get you to 36* total.

Check the module in the HEI. A factory OEM HEI will only wind about 4500. Try using a high performance module or the one from your old distributor.