• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Car cranks but no start. Fuel injectors not releasing gas

Shiftingshaddow

Shiftingshaddow

New member
Hello. I've got a 2000 GTP. Transmission went out so we swapped it out for a different one. Since we were doing this at home and couldn't lift the car very high we decided to just pull the motor and transmission out of the top.

Anyway, got it all back together and it won't start. It cranks but won't turn over. After trying some things think we got it narrowed down to the fuel injectors not working. Pulled the fuel rail off and tried to start it and no fuel is coming out. It will start if you put gas directly into the throttle body.

We've tried to reset the security device thinking that it was locking the fuel injectors but that didn't help. Checked all wires and plugs and grounds. Everything appears good. Our other guess is that the crankshaft sensor is bad. Going to borrow a scanner to see if its going to give us any information.

Anyone have a similar issue or have experience with this?

The car sat without power for nine days. The reason I think it might have something to do with the crank sensor is that the motor was left outside overnight with no rain in the forecast--and what do you know, it rained. It was outside for about ten minutes. Also, coolant got spilled all over out of the block from the lower radiator hose and coolant could have gotten down near the crank area.

Let's see.....what else....new plugs and wires. Changed the valve cover gaskets.....oil pan gasket cleaned up and resealed. Its getting spark off the coils and also through the plugs. Its got gas and fuel pressure--I don't know how much pressure because I don't have a gauge.

Like I said, it starts if gas is put directly into the throttle body.

Any ideas would be greatly appreciated:)
 


If your sure there is fuel at the injectors then check for blown ignition/injector fuses.
 
Good to go. It seems to be an electronic issue. There is fuel in the rail because it comes out pretty good when you push the nozzle where the fuel pressure is tested. When you turn the key to on the fuel pump does its thing. We've tried to start it dozens of times and the lines keep getting pressure.
 


Have you checked for commanded pulse at the injectors?

You can used a marker bulb/light.
Bend the tabs down so they fit in the injector connector and turn the key on. The PCM signal should light the bulb for a split second.
 
If there is a +12 volt at the injectors then it should open up and some fuel will go into the intake runner and the car will start provided that the PCM is switching the ground.

Make sure there is no pulse before you going chasing PCM, wiring or security system issues.
 
Last edited:


just un plug the wire off one injector, take the side marker bulb out of the head light, stick the ends of the bulb into the injector plug, or use a test light. turn the key it should light up, if you crank the engine it should flash. at least they flash when its running i know that much.

if it does not light up or flash, you need to start checking your wires for damage or something else along them lines. it worked before you took it apart, so its something you touched. missed plug ect.
 
If there is pulse and no fuel then it may be an injector problem. If the car is trying to start but won't then a few injectors may not be working.

I would check for pulse at all 6 injector connectors. Takes about 5 minutes.
After you verify this remove the injectors and check them with a 12 volt power supply. They should "click".
If all of them are "clicking" then some may be clogged.
If they're not clogged then it may just be a fuel issue like water contamination or something.
 
I hope I'm not being rude and no doubt you guys know more than me but lets assume there is no pulse......or if there is less than 12v....?
 
No pulse?
PCM or wiring issue. I doubt the security system would prevent the car from starting. Security system will shut the fuel system down after about 5 seconds.

Less than 12 volts?
Again, PCM or wiring.

Is the PCM stock?

Edited: Also make sure the injectors have continuous +12 volts. The Commanded signal from the PCM is switched ground.
 
Last edited:


if we just spit balling imma say crimped wire somewhere if your fuel pump primes your getting power which would = pressure if for some reason the harnesses are not getting that power you have a break in the line or computer issue more than likely a break in the line with taking the engine out and putting it back in . aside for hooking up a corner lamp bulb you could take a voltmeter to them and see if they are getting any voltage if its intermittent or constant. those kinda things might help in diagnosing
 
had this issue myself with a no start first thought it was a bad MAF but turned out to be my fuel pressure regulator relay or sumptin close to that...there is a bypass method on the forums about it
 
Car is all stock.
The security system was an idea from the master tech where we used to work. He said GM cars have an anti theft system that basically shuts off the power for the injectors--at least that is how I understood it. He would do the security relearn procedure if the car had been dead for extended amount of time to get it to start again. Something about it needing reset.

Another idea from another mechanic is that there is not enough fuel pressure.

I'm just a hobbyist, which means when my car breaks I try to fix it myself and if I don't know how I learn:) My brother in law has more general automotive knowledge and experience and so we tackle most things together if necessary. We had the fuel rail off the car and not a single injector is letting any gas out. It may be that there is not enough pressure but it sprays out when you press the fuel pressure nozzle. I cleaned them all off thoroughly so they aren't clogged. When the gas that was poured into the throttle body was burned up the car wouldn't run anymore. Well, more accurately it was idling at high revs and so shut it off after about a minute or two and it wouldn't start again on its own.

I suspected a wiring issue but all the plugs are in. Pulled the heat protector off the wiring harness as best as possible and there is no visible damage. Also checked the fuse box to make sure everything was still connected and the fuses are in good shape. I can't imagine anything happening to the pcm as it just sat there undisturbed after it was out of the air box. Motor or tranny never got close to it.

Would the fuel pump, if already weak, just not be able to give enough pressure if it hadnt been used in over a week? The car has 190K on it.

There wouldn't be any kind of sensor, that if bad, would cause no power to the injectors?

Tomorrow can try more to see if they are getting pulse and check the fuel pressure with a gauge but for now have to ask questions in hypotheticals.
Thanks guys.
 
Going to borrow a scanner and see if it is giving any codes or information. I don't see that leading to much but......maybe. Probably just have to go over wires again very carefully.
 
You must log in or register to reply here.
Back
Top