95 LT1 wont start
08-11-2017, 11:20 PM
#1
Instructor
Thread Starter
95 LT1 wont start
My nephews 95 won't start without putting the pedal all of the way to the floor. Once it starts you have to keep your foot in it to keep it running and it smokes like crazy. The crank case was filled up with gas. We checked the fuel pressure it was about 35 psi. We replaced all spark plugs and injectors and it is still doing the same thing. The optispark, water pump, mass air flow sensor were changed just a few months ago. I am going to look into vacuums or do you guys think I'm wasting my time there and where should I begin? Any advise is a appreciated. Thanks
08-12-2017, 09:17 AM
#2
My nephews 95 won't start without putting the pedal all of the way to the floor. Once it starts you have to keep your foot in it to keep it running and it smokes like crazy. The crank case was filled up with gas. We checked the fuel pressure it was about 35 psi. We replaced all spark plugs and injectors and it is still doing the same thing. The optispark, water pump, mass air flow sensor were changed just a few months ago. I am going to look into vacuums or do you guys think I'm wasting my time there and where should I begin? Any advise is a appreciated. Thanks
08-12-2017, 09:57 AM
#3
Le Mans Master
Or one more injectors that are stuck wide open? It may be worth pulling plugs to see if all cylinders are running uber-rich or just one.
08-14-2017, 04:00 PM
#5
Zen Vet Master Level VII
08-14-2017, 07:56 PM
#6
OK - Holding the gas pedal to the floor tells the computer that the engine is flooded, and the PCM cuts back on the amount of fuel injected to clear the "flooded condition".
So - you need to figure out why you're getting more fuel than you should be.
You say that you replaced the injectors - are you 100% sure that the injectors you put in are the same capacity as the ones you removed ???
If the problem existed before the injector change - and is no different after the injector change - I would look for a bad fuel pressure regulator. You might also want to pull the injectors with their associated fuel supply plumbing and just run the fuel pump with no cranking to see if any of the injectors are leaking (jumper the oil pressure switch to run the fuel pump).
Finally - the way the computer controls the injectors is by completing the ground circuit when the computer wants the injector to fire - so one terminal at each injector is always hot when the ignition is on. So - if there was a short in one of the injector grounds - the injector would always be injecting fuel - this will show up when you pull the injectors and just run the fuel pump without cranking the engine.
GOOD LUCK !!!
So - you need to figure out why you're getting more fuel than you should be.
You say that you replaced the injectors - are you 100% sure that the injectors you put in are the same capacity as the ones you removed ???
If the problem existed before the injector change - and is no different after the injector change - I would look for a bad fuel pressure regulator. You might also want to pull the injectors with their associated fuel supply plumbing and just run the fuel pump with no cranking to see if any of the injectors are leaking (jumper the oil pressure switch to run the fuel pump).
Finally - the way the computer controls the injectors is by completing the ground circuit when the computer wants the injector to fire - so one terminal at each injector is always hot when the ignition is on. So - if there was a short in one of the injector grounds - the injector would always be injecting fuel - this will show up when you pull the injectors and just run the fuel pump without cranking the engine.
GOOD LUCK !!!