94 LT1 Vert
#1
Intermediate
Thread Starter
94 LT1 Vert
Getting sporadic 10 to 15 seconds to crank and turnnover. Just put all new platinum plugs, fuel pressure regulator, and fuel filter in a month ago. Have spent thousands replacing many parts. Was not a hard start before doing plugs etc., was just a rough idle almost choking itself out. Also had smell of gas prior to doing this work. Runs great now, just every now and then is a bit harder to start. Any help would be much appreciated.
#3
Long crank typically means fuel pressure bleed down before start, fuel pump , fuel regulator, injector. Some of the fellas will be along to help you with pin point tests. Good luck!
#4
Le Mans Master
You need to check to see if there is fuel in the vacuum line for the FPR. If it is leaking out it will load up the manifold making starts hard and rich. You can just pull off the line and turn the key to pressurize the system and see if anything comes out.
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don hall (12-07-2017)
#5
Two other very easy things to try -
1) Next time you go to start the car listen to see if you hear the fuel pump run when you turn the ignition on. It's not too loud - but you should be able to hear it - It'll run for a few seconds when you switch the ignition to "on". If you don't hear the pump - the fuel pump relay could be bad - and the fuel pump isn't running till you have the oil pressure switch satisfied (which will also run the fuel pump).
2) Next time it's taking more than a couple of seconds to start - depress the accelerator to the floor while continuing to crank. The PCM will interpret that as a flooding condition, and will back off on the amount of fuel being injected. If depressing the accelerator speeds up the starting - it's quite possible that you have one or more leaky injectors that are causing a difficult to start condition.
1) Next time you go to start the car listen to see if you hear the fuel pump run when you turn the ignition on. It's not too loud - but you should be able to hear it - It'll run for a few seconds when you switch the ignition to "on". If you don't hear the pump - the fuel pump relay could be bad - and the fuel pump isn't running till you have the oil pressure switch satisfied (which will also run the fuel pump).
2) Next time it's taking more than a couple of seconds to start - depress the accelerator to the floor while continuing to crank. The PCM will interpret that as a flooding condition, and will back off on the amount of fuel being injected. If depressing the accelerator speeds up the starting - it's quite possible that you have one or more leaky injectors that are causing a difficult to start condition.