Help guys i need some help, car broke down
11-11-2007, 11:35 AM
#1
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Help guys i need some help, car broke down My car is a 1993 Trans Am LT1 Auto with 44K original miles.
Ok i was driving on the highway last night and all the sudden my car cut out like it wasnt getting gas so i featherd the throttle to keep her going and she started sputtering and then shut off. I put it in neutral and tryed starting it as i was coasting and got nothing. When i try to crank it over it just keeps turning but wont start until i let go of the key then it pops and turns over a little. But not enough to start. I took the cap off the schrader valve on the fuel rail and pushed the nipple down to see if there was pressure and there is plenty. The pump comes on and everything. I have 3/4 tank of gas. I was thinking that the catalytic converter is clogged but i dont know. My friends dad said maybe i skipped my timing chain. How plausable is that? Any info would help. Idk where to start. Im trying to get this fixed today. Thanks
Ok i was driving on the highway last night and all the sudden my car cut out like it wasnt getting gas so i featherd the throttle to keep her going and she started sputtering and then shut off. I put it in neutral and tryed starting it as i was coasting and got nothing. When i try to crank it over it just keeps turning but wont start until i let go of the key then it pops and turns over a little. But not enough to start. I took the cap off the schrader valve on the fuel rail and pushed the nipple down to see if there was pressure and there is plenty. The pump comes on and everything. I have 3/4 tank of gas. I was thinking that the catalytic converter is clogged but i dont know. My friends dad said maybe i skipped my timing chain. How plausable is that? Any info would help. Idk where to start. Im trying to get this fixed today. Thanks
11-11-2007, 12:50 PM
#5
also check the stupid damn ting just above the blster coil in the head, cant remember the name but that has gone out on me twice.. and its cheaper than an opti and you can switch one from another LT1 to check..
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11-11-2007, 03:33 PM
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ok i checked the pressure with a guage and its right at 40psi, i also changed the fuel filter and checked to see if it has spark which it does.
When it does kinda start if i give it gas it dies. It will not idle at all. It spits and spudders and jumps around then dies.
BsGreenZ - what are u talkin about above the coil in the head? a sensor?
When it does kinda start if i give it gas it dies. It will not idle at all. It spits and spudders and jumps around then dies.
BsGreenZ - what are u talkin about above the coil in the head? a sensor?
11-11-2007, 03:40 PM
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when i crank it over it doesnt start no matter how long i hold the key, but when i let off the key it turns over on compression?? It like pops over. it almost like timing is off. What would make that happen without warning.
11-11-2007, 03:56 PM
#11
ok i checked the pressure with a guage and its right at 40psi, i also changed the fuel filter and checked to see if it has spark which it does.
When it does kinda start if i give it gas it dies. It will not idle at all. It spits and spudders and jumps around then dies.
BsGreenZ - what are u talkin about above the coil in the head? a sensor?
When it does kinda start if i give it gas it dies. It will not idle at all. It spits and spudders and jumps around then dies.
BsGreenZ - what are u talkin about above the coil in the head? a sensor?
11-11-2007, 04:11 PM
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Surely if it's got that big of a problem it is throwing codes. Check them...
Are there signs of leaking water from the water pump? Then check the pump and the opti. try putting some heat on the opti over night and see if anything changes in the morning when you try to start it. Keep heat on it until you start it. If the symptoms change, you have water in the opti.
I doubt it is the timing chain at 44k.
I doubt it is the fuel system since you seem to be making enough pressure to idle.
Check to see if wires are touching your exhaust/headers/manifolds. My caprice died in a similar fashion because the harness dropped onto the exhaust manifold. Opened up one of the injectors full blast.
You could have lost your rotor in the opti too. If I were you I would:
- check for codes
- check the wiring harness
- replace the o2 sensors (cant hurt)
- check the coil (if in doubt, replace it)
- check the water pump
- remove the water pump and check the optispark distributor (opti)
- check the opti cap, rotor, and the sensors
- Look into fixing/replacing if water or debris found in the optical sensor housing
- check the pcm
Are there signs of leaking water from the water pump? Then check the pump and the opti. try putting some heat on the opti over night and see if anything changes in the morning when you try to start it. Keep heat on it until you start it. If the symptoms change, you have water in the opti.
I doubt it is the timing chain at 44k.
I doubt it is the fuel system since you seem to be making enough pressure to idle.
Check to see if wires are touching your exhaust/headers/manifolds. My caprice died in a similar fashion because the harness dropped onto the exhaust manifold. Opened up one of the injectors full blast.
You could have lost your rotor in the opti too. If I were you I would:
- check for codes
- check the wiring harness
- replace the o2 sensors (cant hurt)
- check the coil (if in doubt, replace it)
- check the water pump
- remove the water pump and check the optispark distributor (opti)
- check the opti cap, rotor, and the sensors
- Look into fixing/replacing if water or debris found in the optical sensor housing
- check the pcm
11-11-2007, 06:03 PM
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-There are no codes stored.
-The water pump has no signs of leaks, and i hadnt driven it in the rain recently or washed it. I dont think the opti has gotten wet.
-could the ignition control module cause my problem?
-Im doubting its my timing chain also.
-The fuel system is good.
Macs Forever - What do u mean it opened an injector full blast??? Stuck open?
-The water pump has no signs of leaks, and i hadnt driven it in the rain recently or washed it. I dont think the opti has gotten wet.
-could the ignition control module cause my problem?
-Im doubting its my timing chain also.
-The fuel system is good.
Macs Forever - What do u mean it opened an injector full blast??? Stuck open?
11-11-2007, 09:17 PM
#16
How long did the fuel pressure hold at 40#? If an injector is stuck open the pressure will bleed down pretty quickly. You can also try starting the car with the gas pedal floored. This will put the pcm into "clear flood mode" and won't fire the injectors until the car starts.
11-11-2007, 11:08 PM
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Did you check to make sure that your wiring harness on the passengers side didn't fall against the exhaust manifold?
If the sensor on the opti has crap (water or other material) obstructing the sensor, you'll get the problem you describe. Get a timing light, have someone else run the starter on a full battery. Unfortunately, you don't have a timing mark to look at. Maybe point it at the nuts on the harmonic balancer. See if the nuts move back and forth or the light's strobe flash is very inconsistent. If something really serious is wrong, it might be obvious. If you can locate and mark #1 TDC on the balancer, you could see more subtle problems. Too bad GM did away with the timing mark. As I am rebuilding mine, I'll look into putting an after market one on after this.
What to look for with a timing light
- The bolts (or some other identifying mark) on the balancer/pulley should show up in the same position with each flash of the timing light. If the light misses beats, or things seem to be jumping around, you've got cap/rotor problems or sensor problems.
To be clear, the information I have provided is based on a lot of reading not personal experience. I have a ton of experience with Gen 1 engines though. I have an lt1 that I am rebuilding now but it will be next year before I see it run. That's why I've done the reading. The optispark seems to be the weakest link in the lt1. A pre-95 optispark isn't the "latest and greatest" version. Please take the input from others who have personal experience more seriously than mine.
Has anybody out there actually used a timing light to confirm problems with an lt1? If not, can you use a timing light on your good lt1 and confirm or refute what I said? What I'm trying to do is help him narrow the scope without digging too far into the engine.
If the sensor on the opti has crap (water or other material) obstructing the sensor, you'll get the problem you describe. Get a timing light, have someone else run the starter on a full battery. Unfortunately, you don't have a timing mark to look at. Maybe point it at the nuts on the harmonic balancer. See if the nuts move back and forth or the light's strobe flash is very inconsistent. If something really serious is wrong, it might be obvious. If you can locate and mark #1 TDC on the balancer, you could see more subtle problems. Too bad GM did away with the timing mark. As I am rebuilding mine, I'll look into putting an after market one on after this.
What to look for with a timing light
- The bolts (or some other identifying mark) on the balancer/pulley should show up in the same position with each flash of the timing light. If the light misses beats, or things seem to be jumping around, you've got cap/rotor problems or sensor problems.
To be clear, the information I have provided is based on a lot of reading not personal experience. I have a ton of experience with Gen 1 engines though. I have an lt1 that I am rebuilding now but it will be next year before I see it run. That's why I've done the reading. The optispark seems to be the weakest link in the lt1. A pre-95 optispark isn't the "latest and greatest" version. Please take the input from others who have personal experience more seriously than mine.
Has anybody out there actually used a timing light to confirm problems with an lt1? If not, can you use a timing light on your good lt1 and confirm or refute what I said? What I'm trying to do is help him narrow the scope without digging too far into the engine.
11-12-2007, 07:29 AM
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the pressure held for about a minute. I dont think its a leaky injector.
The car wont start if i hold the gas to the floor. It just keeps turning over until i stop cranking then it stumbles to try and start and then dies.
Im going to check the harnesss and plug wires later today.
I would like to know if i could use a timing light on my motor also. If so i need to keep cranking it over to use it bc the motor doesnt run at all???
Is it possible to have spark but not at the right time bc of the optical sensor?
The car wont start if i hold the gas to the floor. It just keeps turning over until i stop cranking then it stumbles to try and start and then dies.
Im going to check the harnesss and plug wires later today.
I would like to know if i could use a timing light on my motor also. If so i need to keep cranking it over to use it bc the motor doesnt run at all???
Is it possible to have spark but not at the right time bc of the optical sensor?
11-12-2007, 08:02 AM
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Just my two cents, but I would see what fuel pressure is whenever you are cranking it and the car is trying to start, possibility that it is going away under a load. Plus the car should hold the 40 psi fuel pressure indefinately without starting, it shouldn't ever bled that fuel pressure down with the key on. If the above doesn't show anything, I would sure look at the opti.....
Good luck with it...
Good luck with it...
11-12-2007, 08:02 AM
#20
the pressure held for about a minute. I dont think its a leaky injector.
The car wont start if i hold the gas to the floor. It just keeps turning over until i stop cranking then it stumbles to try and start and then dies.
Im going to check the harnesss and plug wires later today.
I would like to know if i could use a timing light on my motor also. If so i need to keep cranking it over to use it bc the motor doesnt run at all???
Is it possible to have spark but not at the right time bc of the optical sensor?
The car wont start if i hold the gas to the floor. It just keeps turning over until i stop cranking then it stumbles to try and start and then dies.
Im going to check the harnesss and plug wires later today.
I would like to know if i could use a timing light on my motor also. If so i need to keep cranking it over to use it bc the motor doesnt run at all???
Is it possible to have spark but not at the right time bc of the optical sensor?