94 will not start...
Thread Starter
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
94 will not start...
Unfortunately no history on the car. It was bought and driven home with a rod knock, then trailered to me.
I just rebuilt the motor in a 94 Vette. Started it for the first time today, and it fired right up, and ran good for about 10-15 min. Then it shut off like the key was turned off and will not fire. I have fuel pressure, and spark out of the coil but not to the plugs. No codes jumping it out, but my autoxray will not communicate. I had the opti cap off to check the guts before I put the motor in and it looked ok. Really thinking it's the opti though with no spark coming out. Need to start checking it out tomorrow.
Thoughts?
I just rebuilt the motor in a 94 Vette. Started it for the first time today, and it fired right up, and ran good for about 10-15 min. Then it shut off like the key was turned off and will not fire. I have fuel pressure, and spark out of the coil but not to the plugs. No codes jumping it out, but my autoxray will not communicate. I had the opti cap off to check the guts before I put the motor in and it looked ok. Really thinking it's the opti though with no spark coming out. Need to start checking it out tomorrow.
Thoughts?
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
If you have a strong spark at the coil wire going into the opti but
nothing going to any of the plugs the rotor or the cap must be bad.
Try shorting pin 4 to pin 12 on the diag. connector above the drivers
right knee. Turn the ignition On. Codes for the different modules
will be displayed on the dash cluster LCD.
Module 4 is for the PCM.
Module 1 is for the CCM.
The Autoxray may have problems with the 94 because it's OBD1
with a OBDII connector.
nothing going to any of the plugs the rotor or the cap must be bad.
Try shorting pin 4 to pin 12 on the diag. connector above the drivers
right knee. Turn the ignition On. Codes for the different modules
will be displayed on the dash cluster LCD.
Module 4 is for the PCM.
Module 1 is for the CCM.
The Autoxray may have problems with the 94 because it's OBD1
with a OBDII connector.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Before removing the opti, check the coil wire to see if it is grounding out (sparking) in the area where it goes thru the water pump to top of opti. I had a similar problem and the coil wire was bad.
Otherwise I agree with Hooked on Vettes with all info.
Otherwise I agree with Hooked on Vettes with all info.
Thread Starter
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
Went thru and checked all connections, and reseated the coil wire on the cap side. Car started and seems to be running good. Also found the TPS set way high (reset), and the coolant sensor reading is bouncing around.(ordered new sensor) So, so far so good!
Thread Starter
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
Changed to coolant sensor, took it for a 60 mile run and it ran great. Came home and replaced the oil. Went to take it out today and 10 miles in it started to miss slightly, then got worse. Was running like crap, black smoke if you put it in neutral and reved it. Checked it with a Genisis scanner and no codes. After reading so many posts on the same symptoms leaning again to the opti.
Wish I knew the history of the car because there was a new TBody, new TPS, new coil, and a older reman computer on it already when it was bought. 139k on the car so it's had a busy life!
Wish I knew the history of the car because there was a new TBody, new TPS, new coil, and a older reman computer on it already when it was bought. 139k on the car so it's had a busy life!
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Hi, I agree with Impala Balko. You should pull the coil wire off and test for continuity. Move it around a bit and see if your readings change. If all is well, I would then replace the distributor cap and rotor, which should solve your problem. I don't know if this car uses points or not but see if you have continuity through there too.
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Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Do you have a really good hot 1/2 inch white spark off the coil rather than a weak orange spark. Just wondering about the double check. A weak spark will not get thru the opti cap.
Pulling the opti off again is no fun and is an effort especially when the engine is back in the car.
Pulling the opti off again is no fun and is an effort especially when the engine is back in the car.
Thread Starter
Le Mans Master
Joined: Aug 1999
Posts: 7,339
Likes: 137
From: WilkesBarre PA
There was a very good spark off the coil when I had the no start. Not a big deal pulling it off now, could do it in about 30 min. Just don't want to change a good part. But not knowing the history it may be one way to eliminate one known issue with these cars.