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Engine 91 Gt Slow Starts After It Sits

  • Thread starter Thread starter Jay McElroy
  • Start date Start date Aug 4, 2012
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Jay McElroy

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Aug 4, 2012
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Aug 4, 2012
#1
  • Aug 4, 2012
  • #1
Replaced the fuel pressure regulator and right after that the car cranks for 4-5 seconds before starting and sometimes has a strong odor of fuel. I replaced the fuel pump and 3 leaking injectors but still did not fix the problem. After the car starts you can shut it off and turn the key right back on and it starts with out any hesitation. But once it sits for about 10 mins it goes back to cranking again. Just not sure where to go from here. Thanks.
 

boostfrk

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Aug 4, 2012
#2
  • Aug 4, 2012
  • #2
The strong odor of fuel is suspect. I remember reading about a check valve wearing out and allowing too much fuel drianing back into the tank, which causes longer starts after sitting for a long time because the fuel has to travel back from the tank to the engine. I can't remember, but I think this check valve was part of the pump so if you replaced the pump this may not be a problem.

How is the starter and battery? I kind of have the same problem (at least back when I drove my car since it's sat for the last few months) but I've only got a battery with 450CCA and 540CA.
 

a91what

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#3
  • Aug 4, 2012
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try this.... cycle the key a few times to build fuel pressure... then start the car and see what happens.
 

jrichker

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Aug 5, 2012
#4
  • Aug 5, 2012
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Check fuel pressure:
The local auto parts store may rent or loan a fuel pressure test gauge if you don't have one.
Disconnect the vacuum line from the fuel pressure regulator. Check it for evidence of fuel present in the line by removing it and blowing air through it. If you find fuel, the fuel pressure regulator has failed. Reinstall the line, cap the open end and stow it out of the way.
Connect fuel pressure test gauge to Schrader Connect fuel pressure test gauge to Schrader port located just behind the alternator.
Turn the ignition switch on & start the engine. Observe the pressure : you should see 37-41 PSI at idle.
Turn the ignition off, reconnect the vacuum line and disconnect the fuel pressure test gauge. Watch out for squirting gas when you do this.

If the fuel pump is working like it is supposed to, it will hold pressure for 10-30 minutes after you shut the engine off.

Fuel pump pressure test for a system that will not deliever proper pressure.
Disconnect the larger of the two fuel lines up by the Schrader valve. It is the return line and does not have the Schrader valve on it. Find a piece of rubber fuel hose and clamp it on the return line coming from the regulator. Stick a bolt in the other end of the hose and make sure that all your connections are tight and leak proof as possible. When this powers up, you don't want fuel squirting everywhere. Hook up the fuel pressure test gauge. Turn the ignition switch on and watch for leaks. You may want to use a helper inside the car to cut the switch off quickly if you have a leak. To trick the fuel pump into running, find the ECC
test connector and jump the connector in the Upper RH corner to ground.



Caution!!! You have blocked the return line for the fuel pump! Pressure will rise very quickly past safe levels with a good pump
If the pressure goes up past 55 PSI, the pump is good and the fuel pressure regulator is bad. If the fuel pressure does not hit 55PSI or more in a few seconds, the pump is bad or you have electrical problems.
 
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