*need help with c4 vette for friend

I joined this site with hopes you guys could help me get my buddy some good advice on getting his c4 running.*

He purchased his car about 2 weeks ago from a friend who is a dealer. It ran great the first couple of weeks and some of the things we noticed is the engine is not stock. The rocker covers are taller we are not even sure what engine is in it but it had a aeromotive fpr msd ignition setup larger*throttle*body*andintake*custom*ex haust*etc...etc..*

anyway on to the problem once car was warm and at running temps he would loose control of all the electronics none of the buttons worked radio had distortion in the speakers gauges were still lighting up but not working but once car was turned off for a while it was normal operation once it was restarted.*

A few days later oil light started coming on when cranked checked oil and level was fine. Engine sounded fine no clatter or anything. Would turn car off and back on and light would go off.*

Then it started having idle running issue while stopped at red lights after car was warmed up from driving sometime.*

Then a couple of day later car stopped cranking at all

We pulled diagnostics codes from dash display and c 12 was displayed which means no problem.*

Fuel rail is reading 42-45 psi pulled one of the plugs and checked for spark and is getting a spark and plugs seem fine not old or burnt looking. Engine turns over but will not start.*

We checked all the fuses and couldn't find any that were blown that would relate to starting issue any help would would be great

 

What year car.

what problem do you want to address first?

 

I agree, we need to know the year.

 

Sorry guys didn't realize the year made a difference it is a 95 convertible automatic iirc. Today we disconnected the fuel line at the pump and verified it is pumpumpingping fuel. Then we replaced the fuel filter it was pretty dark and had some buildup on it. I feel even if it wasn't related to the issue it didn't help. Then we unhooked the fuel rail and pulled the injectors out and verified they are spraying a mist of fuel out of each one we then pulled each individual plug wire and checked for spark on each again. The plugs also look great. Also checked the air filter it looks brand new. The battery seemed weak so we had it tested and found a bad cell it was under warranty so we got a new battery. It still turns but doesn't sound like it wants to fire. It's getting spark fuel and fire. I'm limited to experience with 4 cyl engines so beyond this I'm clueless.

 

If I were to take a guess, I might think you had insufficient spark. You have to pull a 1/2 inch white spark to run these engines. An orange small spark won't do it. Also been a lot of problems with aftermarket ignition systems. Not even sure what you got there so hard to tell you what to do.

 

http://www.mainstreamtopics.com/foru...p?showtopic=78

 

I will tell him this . It is a msd ignition box with msd But thanks I had read somewhere about the oil pressure switch going bad in these cars and keeping then from starting a few days prior he mentioned to me his oil light had come on but he checked oil and it was fine then it went away. I read gm had a run of faulty oil switches ?

 

If you're talking about the oil pressure SWITCH that is used for power for the fuel pump then that could be a factor. But the fuel pressure relay also feeds power to the fuel pump. They are in parallel and is basically a redundant system. Even if one fails, the other would supply power to the pump. The pressure switch only needs a few pounds of oil pressure to close.

If the injectors are spraying as you say, sounds like the pump is operating. You can also listen for the 2 second prime of the pump when you first turn the key to the ON position to verify pump action.

 

Oh ok then it's probably not that the pump is defiantly pumping along with injectors.