misfire no codes
Thread Starter
4th Gear
Joined: Apr 2010
Posts: 4
Likes: 0
misfire no codes
I have a 1994 corvette lt1, running poorly, computer wont scan, no check engine light, cylinders 3,5,7 injectors are not firing, these cylinders do have spark just no fuel. I think a major problem is this computer wont scan,checked fuses, dont know where to go from here.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
What do you mean when you say the computer won't scan? Are you using a scan tool or a paperclip to retrieve codes?
Verify you have power at the injectors in question, the PCM fires them by switching the ground. If you have 12 volts at the injectors with the key in the start and run position, trace the ground wires back to the PCM.
Seems more likely to me that you have lost the 12 volt feed since your 94 is sequential fire, good luck.
Verify you have power at the injectors in question, the PCM fires them by switching the ground. If you have 12 volts at the injectors with the key in the start and run position, trace the ground wires back to the PCM.
Seems more likely to me that you have lost the 12 volt feed since your 94 is sequential fire, good luck.
Le Mans Master
Joined: Jul 2004
Posts: 6,227
Likes: 697
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
I have a 1994 corvette lt1, running poorly, computer wont scan, no check engine light, cylinders 3,5,7 injectors are not firing, these cylinders do have spark just no fuel. I think a major problem is this computer wont scan,checked fuses, dont know where to go from here.
Any of the ones you take out look like this?
You may have bad injectors
Thread Starter
4th Gear
Joined: Apr 2010
Posts: 4
Likes: 0
missfire no codes
computer will not scan with scan tool, paper clip, and hypertech power programmer also wont pickup car. Car has 111,174 miles on it. The previous owner changed the ecm at one time, gave the old one with the car to me. I can not get a hold of him to ask why did you change the ecm. So today i will try to trace the grounds back in the loom because I have 12v to the not firing injectors 3,5,7,
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
computer will not scan with scan tool, paper clip, and hypertech power programmer also wont pickup car. Car has 111,174 miles on it. The previous owner changed the ecm at one time, gave the old one with the car to me. I can not get a hold of him to ask why did you change the ecm. So today i will try to trace the grounds back in the loom because I have 12v to the not firing injectors 3,5,7,
I only have a 93 FSM and it uses batch fire injectors so posting my wiring diagram won't do you any good, perhaps someone with a 94-94 will help out if you need one, again good luck.
Not from a FSM, but found this in theCorvette Fuel Injection book, hope it will help.
Last edited by toptechx6; Apr 11, 2010 at 11:00 AM. Reason: picture added
