Help with fuel pump

Discussion in 'Troubleshooting & Diagnosis' started by breesmom1, Nov 21, 2002.

  1. breesmom1

    breesmom1 New Member

    10
    0
    Sep 18, 2002
    Santee, CA USA
    My daughter has a 70 1/2 Camaro Z28, that we bought to fix up. We are not sure if we need a new fuel pump or ???
    We are working on this step by step, it was set up for drag racing and we don't know exactly what it has in it. We switched out the distributor to a HEI and a new dual feed 780 Holley carburater. We are getting 5 pounds of fuel pressure to the carb. It starts then dies right away.
    Thanks in advance!!!
     
  2. dgrewhl

    dgrewhl Veteran Member

    402
    0
    Oct 28, 2002
    north carolina, USA
    Couple things to try.. Run a wire from the hot post of the battery to the ignition terminal on the distributor then attempt to crank it,,finagle/hold the wire to the post so it can easily be removed if it runs,,,that'll at least prove that the ignition circuit is correct,,if that works recheck the ignition wire for a full/constant 12 volts,,,....Second try disconnecting the fuel line from the carb and hold the line in a bottle/jar (make sure the ignition wire is diconnected from the distributor) and turn it over a few seconds,,,should be a good steady stream,,,,that'll give you a chance to look for contaminants,,mainly water...I guess you also try spraying starter fluid in the carb and see if you can keep it running that way too....5 psi should be enough to at least crank it and idle....g'luck!
    mike
     
  3. craggar

    craggar Veteran Member

    5,769
    0
    Jul 28, 1999
    edmonton
    What was there before you switched to HEI and electric or mech. pump?5 psi is plenty to run most engines even at wot.
    It sounds electrical to me as in what dgrewhl has mentioned,does it stop as soon as you let off the key from the cranking position?
     
  4. camaro78

    camaro78 Veteran Member

    479
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    Apr 7, 2001
    Central Iowa
    When you converted the car to HEI, did you make sure you had a full 12 volts at the distributor?

    The point type distributors have a resistor in the line to drop the voltage. An HEI setup won't work properly this way.

    Do a search on this site, the conversion has been discussed several times.

    ------------------
    My 74 Camaro
    My 78 Camaro
    My Website
    mailto:jrwrigh@iastate.edujrwrigh@iastate.edu</A>
     
  5. breesmom1

    breesmom1 New Member

    10
    0
    Sep 18, 2002
    Santee, CA USA
    Hi, thanks for the responses! [​IMG] The old distibutor was mech. The car stops a few seconds after you turn the key. We put new fuel lines on, emptied the gas tank and then added new gas.
    BTU - there are two fuel pumps set up. Yes I know that this is not normal. There is one regular one by the engine and one electric one by the tank. They both seem to work, we can switch between them. Does it matter which one we keep hooked up?
     
  6. craggar

    craggar Veteran Member

    5,769
    0
    Jul 28, 1999
    edmonton
    Tell us more about your engine is it a bb or sb,was it built for the track or street or both.Running 2 pumps isn't that uncommon but if the electric is good then you can pull the mech. and put a block off plate and just run the one or just bypass the electric if you want.
    It does sound like you are only getting 12V while cranking and not in the run position on the ign.
     
  7. breesmom1

    breesmom1 New Member

    10
    0
    Sep 18, 2002
    Santee, CA USA
    We were told it's a small block with roller rockers and it's a high proformance motor. We haven't gotten into the engine yet. They used it for drag racing with nitro. When we bought it they had started putting in a new wiring harness. So it wasn't running then. We finished the wiring, then did the distributor and carb. We are learning as we go.
     
  8. craggar

    craggar Veteran Member

    5,769
    0
    Jul 28, 1999
    edmonton
    The nitrous explains the second fuel pump and what you said about the wiring not being complete makes it sound more like you don't have 12v going to the dist. in the run position.Try what dgrewhl said and see if that works.
     
  9. Rick's Z

    Rick's Z Veteran Member

    366
    0
    Jun 27, 2001
    Dover, DE
    Just stabbing at it but has the fuel filter been checked after the tank was drained, and refilled who knows what crap was kicked up and possibly clogging a filter.
    Rick
     
  10. Rick's Z

    Rick's Z Veteran Member

    366
    0
    Jun 27, 2001
    Dover, DE
    well..............? any progress
     

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