So among the many issues that I'm trying to figure out on my (new to me) 94 Z28, I've got one that's impeding my progress more so than the others.


This particular problem comes after the car has warmed up (Doesn't have to be full operating temp) For example, I charged the AC system, so I started the car and let it run for about 3 minutes or so to see if the AC pump would kick in. It didn't so I shut the car off, put some more 134 in it, and went to start the car again. When you try to start the car again, it acts like the battery is half dead, barely cranking over, or in spurts; it acts like the timing is way advanced, it will actually stop the starter from turning the engine over, so I turn the key off and try again, if the engine actually fires it will start most of the time.

So, is it possible that for some reason the timing gets way advanced on a warm start? This isn't intermittent, it happens every time. Cold starts are fine, it's when the car runs for a few minutes that all hell breaks loose (mis-fires, idle issues, etc).

It has a new battery and a new starter. I even put the big charger on it on boost and it made no difference what-so-ever in how the car turned over.

The SES light is on, but I haven't been able to pull the codes yet - but I don't know if that would tell me anything about this particular condition. I'm putting off buying the kit from tunercat.com to hook to the laptop for $160.

I don't know if the computer has been messed with prior to me getting the car - I noticed all that polution control stuff is unhooked and unplugged as well.

Any ideas? This LT1 is really getting to be a pain in my ****. I have several issues I'm trying to track down but I'm trying not to cloud a thread with a bunch of different things at once.

 

problem could be one or more of many things. best to start by getting it scanned for trouble codes. could try testing everything you can. like the ignition control module, all temp sensors, map, egr, evap. check here 4th Gen LT1 F-Body Tech Aids and here https://camaroforums.com/forum/93-02...62/#post557634

 

That light doesn't go on just because the car may think you like to look at that pretty shade of red.
It's on to tell you that something is wrong. And, scanning the system saves you time because you're not chasing your tail, and saves you money by preventing you from throwing unnecessary parts at the car.
When there's a symptom, and the SES light is on, getting it scanned is step 1 (unless you're psychic).

 

the polution control stuff is completely unhooked as far as I can tell, plugs dangling and hoses hanging.

And sigh.. scanning for trouble codes. Wish I could. guess I'm going to have to whip out the wallet. And wait for my service manuals to arrive.

 

I just can't fathom what sensor would cause the car to turn over just fine cold, but act like it has way too much advance warm.

 

I can't either, but you could have more than one thing going on. To eliminate the ignition as the slow crank culprit, disconnect your coil wire. With the plugs not firing, the ignition timing will have no effect on cranking. If it still cranks slow, there goes your theory.

 

worn out starter will do that

 

That's exactly what I was thinking, till I got to the middle of his saga:

 

I'll just have to wait until I can pull the codes. None of the shops around here seem to have the correct equipment. Autozone claims they do but they don't.

 

That the emission equipment is disconnected could be the reason the car seems to be running rich. The computer may read the missing emission control data as a lean condition and is dumping excess fuel to compensate.

If autozone can't pull the codes, call around to different repair shops and see if any of them will pull codes for free. Many shops will pull codes for free or a small charge. Until you know what codes are in the computer, you are going to be chasing your tail.

That the previous owner disconnected a bunch of stuff and just left the wires hanging is not a good sign. You have to wonder why did they do that? Could be that they had a problem and someone told them to start pulling emissions stuff off to fix it or something.

You could try hooking up everything again, and then disconnect the battery for 30 minutes or so to reset the computer. But I suspect that the SES light will remain on as the prior owner did some butchering under the hood.

Ideally you will get the car back to factory configuration and make sure it is running right before you start modding it. The factory configuration is a good baseline to have a decent running and reliable car.