'96 Sunfire 2.4 5sp will not start without starting fluid?
Maui Beach Bum
07-18-2011, 02:57 PM
Hello to the forum.
'96 Sunfire, 2.4,5Sp,with 120k.
I'll get right to the problem. I just bought this car,so the history is mostly unknown.
What I do know is it will not start without the addition of starting fluid,even once its at operating temperature. Once it starts it surges quite a bit until it warms up some. I managed to drive the car home from where I bought it,which wasn't an easy task. When the RPM was taken above the 3k point the engine had a combination of popping back, backfiring,and trying to shut down.
The area around the exhaust pipe looks as if the engine has been running rich for a long time. (heavy black deposits on the bumper)
Any ideas of what might be causing this problem?
Items that the PO replaced in an effort to find the cause are...
fuel pump,fuel pressure regulator,air & fuel filters,and the coil packs. There may have been other parts replaced,but those were all the PO could recall at the time.
The engine sounds good when it is running. No ticking or knocking,etc.. Just falls apart above 3k and won't start on its own.
The CEL is not on. :confused:
Thanks for any ideas.
'96 Sunfire, 2.4,5Sp,with 120k.
I'll get right to the problem. I just bought this car,so the history is mostly unknown.
What I do know is it will not start without the addition of starting fluid,even once its at operating temperature. Once it starts it surges quite a bit until it warms up some. I managed to drive the car home from where I bought it,which wasn't an easy task. When the RPM was taken above the 3k point the engine had a combination of popping back, backfiring,and trying to shut down.
The area around the exhaust pipe looks as if the engine has been running rich for a long time. (heavy black deposits on the bumper)
Any ideas of what might be causing this problem?
Items that the PO replaced in an effort to find the cause are...
fuel pump,fuel pressure regulator,air & fuel filters,and the coil packs. There may have been other parts replaced,but those were all the PO could recall at the time.
The engine sounds good when it is running. No ticking or knocking,etc.. Just falls apart above 3k and won't start on its own.
The CEL is not on. :confused:
Thanks for any ideas.
inafogg
07-18-2011, 05:02 PM
if spraying carb cleaner starts the engine & it stays running on its own you need to check
the fuel pressure.key on engine off,running pressure,& pressure when its turned off.
sounds like it could be a bad pump or its not holding pressure in the system.i dont think there is a test port on your modle so you'll
need to find a way to tie in a guage. on my 98 2.4 i tapped in right at the pressure line coming off the pump
the fuel pressure.key on engine off,running pressure,& pressure when its turned off.
sounds like it could be a bad pump or its not holding pressure in the system.i dont think there is a test port on your modle so you'll
need to find a way to tie in a guage. on my 98 2.4 i tapped in right at the pressure line coming off the pump
Maui Beach Bum
07-18-2011, 11:48 PM
if spraying carb cleaner starts the engine & it stays running on its own you need to check
the fuel pressure.key on engine off,running pressure,& pressure when its turned off.
sounds like it could be a bad pump or its not holding pressure in the system.i dont think there is a test port on your modle so you'll
need to find a way to tie in a guage. on my 98 2.4 i tapped in right at the pressure line coming off the pump
Thanks for the idea.
I brought my scan tool home today and there's a list of sensors that aren't functioning. I'm not sure if all the sensors are bad,or if one is failing due to another not working.
I couldn't get the engine to start again today, so I couldn't do a KOER test,but I did notice that the tach isn't working. So now I'm leaning towards the PCM not sending a signal to the injectors. Any idea which drives the tach,the CKP,or the CMP?
Both of these sensors along with the TPS are out of whack,if the scanner is to be believed. I'm going to try the easy one (the CMP) first. I can't even see the crank sensor. My thought is the same signal for the tach is also used by the PCM to drive the injectors. I may be wrong about this,but its worth a shot to replace the CMP,its only a $15.00 part.
Maybe I'll get lucky,for a change.:lol:
Thanks again.
the fuel pressure.key on engine off,running pressure,& pressure when its turned off.
sounds like it could be a bad pump or its not holding pressure in the system.i dont think there is a test port on your modle so you'll
need to find a way to tie in a guage. on my 98 2.4 i tapped in right at the pressure line coming off the pump
Thanks for the idea.
I brought my scan tool home today and there's a list of sensors that aren't functioning. I'm not sure if all the sensors are bad,or if one is failing due to another not working.
I couldn't get the engine to start again today, so I couldn't do a KOER test,but I did notice that the tach isn't working. So now I'm leaning towards the PCM not sending a signal to the injectors. Any idea which drives the tach,the CKP,or the CMP?
Both of these sensors along with the TPS are out of whack,if the scanner is to be believed. I'm going to try the easy one (the CMP) first. I can't even see the crank sensor. My thought is the same signal for the tach is also used by the PCM to drive the injectors. I may be wrong about this,but its worth a shot to replace the CMP,its only a $15.00 part.
Maybe I'll get lucky,for a change.:lol:
Thanks again.
Maui Beach Bum
07-19-2011, 11:26 PM
Update,
Replaced both the CMP and the CKP sensors and the engine still does not start. I knew better but took the chance that changing out the sensors might cure the problem.
Anyway, I suppose the next step is tearing off the inner fender for a look at the PCM wiring connection.
I did read that the timing chain being loose can cause problems. Anyone know if this is true? When the engine was running it sounded fine. there wasn't any chain noise that I could hear , and I'd think a chain loose enough to cause a problem would be making some kind of racket.
As well I saw where the timing being off from the chain jumping could cause a problem. Again ,the engine didn't sound as if it was out of time , and except for not wanting to run above 3k rpm , it sounded normal.
It seems as if there is no signal getting either to , or from the PCM. Is there any type of low oil , or over temp shut down protection on this engine that may have stopped working?
How common are problems with the wiring connection at the PCM? I can't understand what GM could have been thinking when they located the PCM in the fender well,but that has to be about the dumbest place ever to locate a computer. What was wrong with locating it inside the car?
I've only had the car for 2 days and I'm already regretting buying it. On top of it not running , know one knows what's wrong.
Thanks again for any input.
Replaced both the CMP and the CKP sensors and the engine still does not start. I knew better but took the chance that changing out the sensors might cure the problem.
Anyway, I suppose the next step is tearing off the inner fender for a look at the PCM wiring connection.
I did read that the timing chain being loose can cause problems. Anyone know if this is true? When the engine was running it sounded fine. there wasn't any chain noise that I could hear , and I'd think a chain loose enough to cause a problem would be making some kind of racket.
As well I saw where the timing being off from the chain jumping could cause a problem. Again ,the engine didn't sound as if it was out of time , and except for not wanting to run above 3k rpm , it sounded normal.
It seems as if there is no signal getting either to , or from the PCM. Is there any type of low oil , or over temp shut down protection on this engine that may have stopped working?
How common are problems with the wiring connection at the PCM? I can't understand what GM could have been thinking when they located the PCM in the fender well,but that has to be about the dumbest place ever to locate a computer. What was wrong with locating it inside the car?
I've only had the car for 2 days and I'm already regretting buying it. On top of it not running , know one knows what's wrong.
Thanks again for any input.
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