92 Corvette stroker

Problem: Motor turns over, it just doesn't start running. Smells very rich when i try and if it does start the car runs very rich. It does this if it sits for awhile (24 hours) and it's a little cold out, until one afternoon it will just start right up.

Things I've checked...

1. Fuel pressure doesn't leak down (injectors, pump), FPR is not wet. Fuel pump is new.
2. No wet plugs
3. Spark plugs = New
4. Spark Wires = New
5. Good spark from coil to opti
6. Good spark from opti to plugs
7. Took the battery to autozone, it's good
8. Nothing blocking air into intake
9. Fuses good (This is an intermediate thing so i knew before i checked they were good)
10. No codes. (Just the 12 code)
11. Noid light blinks on injectors
12. I have no MAF sensor
13. Emissions removed.

Could this be a bad CTS? There are no codes which leans me away from the CTS but from reading on here, it's got alot of the same systems.

 

The CTS is worth checking.

 

Ok, i just checked it with my volt meter. Keep in mind i never claimed to be an electrician.

The harness that plugs into it i got 5 on the V dial of my volt meter. For the sensor itself i switched my volt meter to the ohm side to the 20m selection. I'm not sure if i was hitting the metal on the sensor or what because i couldn't see it but it would jump up to around 18.54 and then it would just show a -1

 

You need to be sure you are firmly on the two pins of the sensor and you should get a steady reading. Try to use the lowest ohms scale that does not cause the meter to go over limit. Keep in mind that this test is just to try to rule out the sensor as a suspect.

 

That wasn't it i don't think. I bought a new one and put it in my frost covered car and still no start. When it get's a little warmer out i'll try to start it again.

 

What about the TPS, check it by probing the wires going to it it should vary resistance when you open and close the throttle blades. Also make sure the MAP sensor is plugged in.

 

You stated you have good spark; how did you determine it was good? I got bit diagnosing an ignition problem by assuming the spark was good; turned out to be a marginal spark caused by a weak coil. Most auto parts stores sell a spark tester for about $10; it has an adjustable gap. A good spark should easily jump 3/4".

 

I have a spark tester, that's how i tested it.

 

I'll check the MAP real good. The TPS though, if it was bad wouldn't it always be bad? This car seems to run fine on warm days.

 

I've heard of the TPS being bad only at certain points so maybe give it a little gas when you start it up to see if works that way.

 

Usually it turns to crap when it warms up, not the other way round. Is it possible you have moisture in the fuel filter that freezes and causes a partial blockage????

maybe an ignition power issue. Not enough umph when cold to fire the fuel.

You sure it's not an issue of cranking slowly?

 

The fuel pressure seems fine so i don't think it's the filter. At this point though anything is possible.

It's not cranking slowly.

I had a thought about it while i was trying to go to sleep this morning. If it only happens when it's cold, i could take my wife's hair dryer outside and warm up various parts to see if i can get it to get started then.

 

Look at the coil and see if it has any white spots/marks near the laminations. Watch it carefully in the dark to see if it's arcing. The only thing I've seen resembling your problem was a friends 6 cylinder that had worn out ignition components. Caused hard starting when cold. Would restart hot no problem. He only required an ignition tune up.

Perhaps you have a weak component in the ignition system. Coil would be my first guess.

I don't think the blow dryer will work for you. I think the cylinders have to be heated. but hey it won't cost anything to try.

Oh yeah, ever checked compression??????

 

I checked the coil and it did arc and i'm still getting the spark out of the plug wires. I haven't tested compression yet, haven't had time or the tools.

The car should be getting traded in one way or the other in a couple weeks. I'll drive the bastard up there on a day it's running and tell them to have it.

I would have already taken it to a shop, but i know the first thing they are going to say is it's the opti and i'm going to spend alot to swap it and it's still going to be broke.

 

Are you saying the coil did arc BEFORE you changed it? Cause if it hasn't been changed, there you go. Any time it arcs, your loosing spark energy going to the plugs. Possibly making it harder to start when cold. In any event, the coil should be changed out if it hasn't already.