1994 Corvette C4 Major Issues
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From: Rancho Santa Margarita California
1994 Corvette C4 Major Issues
So I have had my corvette for about a year now. I got it in top of the line condition until it started to fall apart right about now. So about two weeks ago it started raining. I drove my vette in the rain everything was fine. Next day I'm driving accelerate a little and the engine dies. No lurching, backfiring nothing I'm just coasting down the road. I get it to start and drive it home and it runs good for about another week. Then i go to start it a few days after and it wont turn over. Eventually it starts to turn over about 1/2 of the times I try to start the car. It is still that way. In my quest to fix it I have installed a new Fuel Pump, Fuel Regulator, and have checked and cleaned the ground straps but its still the same. Any ideas on how to fix? could it be the opti? Thanks.
Race Director
Joined: Mar 2015
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Pull the battery and clean and test and right behind it there is a jump box clean and check there look at the fuseable link since your right there but sounds like the jump box.
Last edited by antfarmer2; Mar 30, 2016 at 08:19 AM.
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From: Rancho Santa Margarita California
Melting Slicks
Joined: Aug 2008
Posts: 2,082
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From: Palmdale CA
OP make sure you read this closely, and take your time.. there may or may not be any codes stored.
http://tech.corvettecentral.com/2011...trouble-codes/
http://tech.corvettecentral.com/2011...trouble-codes/
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Thread Starter
Intermediate
Joined: Mar 2016
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From: Rancho Santa Margarita California
Thanks but I've tried most of this
I've actually bought an obdII scanner and went through all the codes there aren't any that concern problems with the engine odly enough. I'm really starting to think it could be the optispark I've heard if those get wet its bad news. I'm really at a loss of what the problem could be for this car... For instance I started the car today and it ran fine in the morning. Then towards the afternoon it died while I was driving again and I just coasted to the side of the street. I also think it could be a bad injector, and it is also worth noting for some reason the cars fuel pressure runs at about 33 Psi when the car is on even after I installed the new regulator and pump. Anyways thought those could be some useful hints.
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From: Rancho Santa Margarita California
One last thing
Sorry I also forgot to mention when the car is in the on position in the warning lights window on the dash a battery light and service engine light comes on. Is that standard on all c4's in the on/run position or not. Because when I turn the car on they disappear.
Last edited by PsarosJake; Mar 30, 2016 at 12:09 PM.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
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From: Orlando FL
Basically yes.
When the key of first turned to ON, lots of lights on the DIC come on. In a few seconds many of the lights go out (a form of self test). When the engine is started, all the lights should go out including the SES light.
When the key of first turned to ON, lots of lights on the DIC come on. In a few seconds many of the lights go out (a form of self test). When the engine is started, all the lights should go out including the SES light.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
I've actually bought an obdII scanner and went through all the codes there aren't any that concern problems with the engine odly enough. I'm really starting to think it could be the optispark I've heard if those get wet its bad news. I'm really at a loss of what the problem could be for this car... For instance I started the car today and it ran fine in the morning. Then towards the afternoon it died while I was driving again and I just coasted to the side of the street. I also think it could be a bad injector, and it is also worth noting for some reason the cars fuel pressure runs at about 33 Psi when the car is on even after I installed the new regulator and pump. Anyways thought those could be some useful hints.
To pull the codes (on board) you will need some links and information on how to perform the process.
It sounds like 2 problems here. A cranking problem and engine quit problem.
Could be several things but sure sounds like might be a ICM as only of one of the possibilities.
If it does not crank, you might be looking at a bad starter. Listen and see if you hear the solenoid click.
Thread Starter
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From: Rancho Santa Margarita California
The car does crank
Vetts of 94-95 are OBD1 systems but have OBD2 connectors. It was the crossover years when in 96 all cars ran OBD2. A OBD2 scanner will not show any codes or for that matter communicate with the PCM or any system on the car. The on board diagnostics will show the codes for all the modules. There are a few scanners out there with the proper software and physical connector that can show the codes for the PCM.
To pull the codes (on board) you will need some links and information on how to perform the process.
It sounds like 2 problems here. A cranking problem and engine quit problem.
Could be several things but sure sounds like might be a ICM as only of one of the possibilities.
If it does not crank, you might be looking at a bad starter. Listen and see if you hear the solenoid click.
To pull the codes (on board) you will need some links and information on how to perform the process.
It sounds like 2 problems here. A cranking problem and engine quit problem.
Could be several things but sure sounds like might be a ICM as only of one of the possibilities.
If it does not crank, you might be looking at a bad starter. Listen and see if you hear the solenoid click.
And about the obdII thanks for the info I will be sure to check that out
Team Owner
Joined: Sep 2003
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There's several posts that have been deleted by the Moderators and I get it(understand). The link to the diagnostics by "desertmike1" can be used to "help" - not solve but help.
OP - just needs to spend some time with the car.
A FSM for the diagnostic tree information is nearly a must for these cars.
Access to a correct scanning device certainly is a plus. I've seen some conversation regarding a 1320XXX or something like that. I'm not familiar with it. I have Tech1 and a Tech2 and do pretty well with them.
"93rubie" has spent some time with a thread he created but seems a bit discouraged with it's repentance. I don't watch many videos, I don't do YOU TUBE but if I were needing some help "93rubie" or yourself (pcolt94) might be my go to. I believe I've gone to BOTH previously.
OP - I was typing while you responded - hang in there!!
OP - just needs to spend some time with the car.
A FSM for the diagnostic tree information is nearly a must for these cars.
Access to a correct scanning device certainly is a plus. I've seen some conversation regarding a 1320XXX or something like that. I'm not familiar with it. I have Tech1 and a Tech2 and do pretty well with them.
"93rubie" has spent some time with a thread he created but seems a bit discouraged with it's repentance. I don't watch many videos, I don't do YOU TUBE but if I were needing some help "93rubie" or yourself (pcolt94) might be my go to. I believe I've gone to BOTH previously.
OP - I was typing while you responded - hang in there!!
Last edited by WVZR-1; Mar 30, 2016 at 03:04 PM.
Thread Starter
Intermediate
Joined: Mar 2016
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From: Rancho Santa Margarita California
Thanks
There's several posts that have been deleted by the Moderators and I get it. The link to the diagnostics by "desertmike1" can be used to "help" - not solve but help.
OP - just needs to spend some time with the car.
A FSM for the diagnostic tree information is nearly a must for these cars.
Access to a correct scanning device certainly is a plus. I've seen some conversation regarding a 1320XXX or something like that. I'm not familiar with it. I have Tech1 and a Tech2 and do pretty well with them.
"93rubie" has spent some time with a thread he created but seems a bit discouraged with it's repentance. I don't watch many videos, I don't do YOU TUBE but if I were needing some help "93rubie" or yourself (pcolt94) might be my go to. I believe I've gone to BOTH previously.
OP - I was typing while you responded - hang in there!!
OP - just needs to spend some time with the car.
A FSM for the diagnostic tree information is nearly a must for these cars.
Access to a correct scanning device certainly is a plus. I've seen some conversation regarding a 1320XXX or something like that. I'm not familiar with it. I have Tech1 and a Tech2 and do pretty well with them.
"93rubie" has spent some time with a thread he created but seems a bit discouraged with it's repentance. I don't watch many videos, I don't do YOU TUBE but if I were needing some help "93rubie" or yourself (pcolt94) might be my go to. I believe I've gone to BOTH previously.
OP - I was typing while you responded - hang in there!!
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
It sounds like 2 problems here. A cranking problem and engine quit problem.
Could be several things but sure sounds like might be a ICM as only of one of the possibilities.
If it does not crank, you might be looking at a bad starter. Listen and see if you hear the solenoid click.
Could be several things but sure sounds like might be a ICM as only of one of the possibilities.
If it does not crank, you might be looking at a bad starter. Listen and see if you hear the solenoid click.
Thread Starter
Intermediate
Joined: Mar 2016
Posts: 47
Likes: 0
From: Rancho Santa Margarita California
Yes it only occasionally starts up and when it does it sounds bad and it's hard to describe but you get that sense of wow that wasn't supposed to happen. Then you take it out for a drive and it either runs like a champ or dies.
Team Owner
Joined: Aug 2004
Posts: 21,543
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From: Park City Utah
This thread is going absolutely no where. IDK what posts were deleted, but I can imagine.
OP. If ya want some help, help yourself by giving useful and clear information in your posts. This stuff;
"it sounds bad and it's hard to describe but you get that sense of wow that wasn't supposed to happen"
...isn't doing it. WTF does that mean to anyone?? It means nothing. Post a video if you have bad sounds. Be clear; does the starter turn the flywheel every time you turn the key to crank? Or not? We don't know. Earlier you indicated that it doesn't...now it seems like it might. BE CLEAR, or your not going to get anything but more questions, and/or WAG's. Are WAG's any help? No, they're not.
If the starter cranks (that means, "turns the flywheel") the engine when you move the key to start, but the engine doesn't start, or the engine stalls while running, you've lost spark or fuel. SO, when the symptom occurs, which is missing; spark or fuel? Don't need a scanner to figure that one out...open the hood, see which element is missing. Post back, with some clarity.
.
OP. If ya want some help, help yourself by giving useful and clear information in your posts. This stuff;
"it sounds bad and it's hard to describe but you get that sense of wow that wasn't supposed to happen"
...isn't doing it. WTF does that mean to anyone?? It means nothing. Post a video if you have bad sounds. Be clear; does the starter turn the flywheel every time you turn the key to crank? Or not? We don't know. Earlier you indicated that it doesn't...now it seems like it might. BE CLEAR, or your not going to get anything but more questions, and/or WAG's. Are WAG's any help? No, they're not.
If the starter cranks (that means, "turns the flywheel") the engine when you move the key to start, but the engine doesn't start, or the engine stalls while running, you've lost spark or fuel. SO, when the symptom occurs, which is missing; spark or fuel? Don't need a scanner to figure that one out...open the hood, see which element is missing. Post back, with some clarity.
.
Last edited by Tom400CFI; Mar 30, 2016 at 02:16 PM.