I'm baaaaack... I posted on here a few weeks ago with what I thought would end up being a pretty routine fix for a stock '90 RS that suddenly began running poorly. Unfortunately, none of the possibilities I thought of or that others suggested turned out to be the case (cracked distributor cap, bad plugs/wires, bad fuel pump).

I did find a pigtail coming from the distributor that had been rigged at one point (looked like the wires had been cut and some moron had just taped them back together). I replaced that, but it didn't solve the problem of the godawful idle.

I finally broke down and had my car towed to pros last weekend. They called me tonight and told me it was one of the most confusing things they'd ever had to deal with. Apparently, some parts of my car are just..."not responding" when they hook it up for diagnostics (02 sensor, throttle and a few other things). The engine starts fine and despite the horrible idle, it stays running. It just doesn't play ball with the diagnostic.

Some other things they mentioned:

-2 cylinders have pressure that's not quite where it should be
- my car is running too rich
- I am missing a few wires (didn't specify which)
- there's definitely a vacuum leak in the manifold somewhere, they just haven't found where yet

My first reaction was along the lines of "Oh, God...do I need a new engine?" They didn't seem to think so...their consensus was more that it's a combination of multiple "little things" that are causing it to run badly. The problem both from the repairman's standpoint and my wallet is figuring out WHAT little things need fixing and the computer issue is mucking that up.

I've had the car for 6 1/2 years and while I've had to replace a few routine things, it's been running the whole time, often as a daily driver. It's been hooked to diagnostic computers before and responded like it was supposed to....anyone have any clue what might cause it to not respond now?

They're still working on it, of course, but I'd love some possibilities to discuss with them so that I don't sound like a complete moron when talking to them.

 

The first thing to do is check all of your wire grounds.

 

if I were you, I would hit the local junkyard and see if you could get your hands on a harness and ECM with Prom... one JerryRig fix pretty much warrants the believe that other repairs were done in similar fashion...

 

I'm not sure if they've checked the grounds yet, but I'll definitely ask them to if not!

As for the wiring harness and ECM/PROM... is that something that would be specific to a Camaro, or did Chevy use the same harness/ECM in multiple vehicles? Sorry if that's a stupid question, but I scoured every junkyard I could find when I was searching for parts to restore my car's body and there was not a third gen to be found in any of them.

 

Oh, this is bad....

I just got off the phone with the mechanic. Still no luck. Apparently, nearly EVERYTHING under my hood is NOT what is supposed to be on a '90 RS. He said there's so many little things wrong with the car that it's "not worth it" to fix....

Just one problem.

A few months ago (when it was still running perfect), I finally had it totally restored on the exterior. Everything refitted perfectly, new paint and trim, everything. Well into the thousands of dollars.

And now I'm supposed to practically give it away to someone who can afford the time and parts or junk it....

I'm beyond upset...I'm very confused, as while I knew a few things were not what they should be under the hood thanks to mechanics in the past, no one before has told me that nearly everything was wrong.

Anyway...now desperately seeking a parts car with everything good under the hood.

Crap....and I'm supposed to be moving in about 6 weeks, too....

 

Depends what you are dealing with.
If it is primarily to do with the wiring I would do as suggested and start by fitting a good stock engine harness.
Always guys parting out cars on 3rd Gen for sale section.
You say car was fine ; strange for everything to give up the ghost suddenly

 

I know! That's what I thought was so weird about it. If I have no luck finding a parts car, I may just have to start replacing all the garbage one thing at a time until all the known issues are solved and the car is running right again.

There is no way I'm giving up on the car...not after investing nearly $6,000 in the body work, upgrades and paint (long story short, it was technically totaled, but the damage was miraculously entirely cosmetic and as it was my first car, I decided to go the whole nine yards and restore everything). Whether I go for a whole new "under the hood" or go at it piece by piece, I know it's gonna cost me some serious cash now.

Yesterday, the mechanic didn't seem to think the engine itself was the issue...just an unknown combination of "little things" that all went wrong and will take hours to fix- kinda why he didn't think it was worth it until I told him about the body work. I've already got $$$ invested in it and there's no way I could ever get half of that trying to sell it as is (not that I would, anyway).

 

Why not just thank the mechanic, pay him for his diagnostic time, bring it home, and fix it? $300 would easily replace everything that could possibly be wrong.

Start with the vacuum leak - a $3 can of carb cleaner will tell you where the vacuum leak is - and fix that FIRST. Best case, a $2 vacuum hose, worst case, a $20 intake gasket.

Basics: Check the injectors - they should spray nice conical pattern, no dripping. They are only $60 a piece, and there's only 2!

New wires, cap, rotor, plugs. Test continuity on all wires before install, to make sure none are bad (new ones are often bad). Properly gap plugs. Make sure firing order is correct. Get a $20 timing light and check timing - remember to unplug the EST. Try replacing the ignition module inside the distributor.

Sensors: Replace O2, see what happens. Then MAP, and test again. And so forth. You've got O2, MAP, TPS, & IAC. Any I'm forgetting? Oh - IAT in the air cleaner housing.

Thus far, if all this is done, you've invested about $240 total (including timing light but NOT including injectors), and a weekend.

If all that fails, then search here in classifieds or Thirdgen Ranch, Hawks, ebay, whatever and try another chip in the ECM Rare that an entire ECM goes bad, usually just chip needs replaced (and that's rare as well). Used TBI chip shouldn't sell for more than $40 - heck you can get a Jet chip for under $100.

Anyone that says a newly painted 3rd gen TBI isn't fixable ... isn't much of a mechanic anyway. The TBI system is about as easy as it gets. Few sensors, very reliable setup.

You can check your own codes along the way with a paperclip! See the tech articles for diags info. If everything I mentioned is done, $400 or so is about all the damage you'll incur - and everything will be new! It's not that hard to replace these things. An extra $20 will buy you a Haynes manual to guide you along the way.

If you decide to sell - don't take a beating on it - if you've got that much tied up in body work/paint, you will never see all of it back, but I wouldn't sell it dirt cheap. The body/paint cash is already gone, so it won't hurt you to take you're time selling and hold out for a respectful buyer!

Good Luck!

 

Thanks for the suggestions!

The only downside to my car is that it's NOT set up the way it's supposed to be. There's a few nasty rigged places and some missing parts.

Things are looking up, though. I do have a Haynes manual and will be heading down to the shop along with my bro (longtime 4th Gen owner) to have a good, long look and find out what all is and is not there, according to the manual. I think I'm going to go with replacing everything that's missing/could be wrong and see if that does the trick.

I guess me looking for a whole new engine may have been a bit of an overreaction. On the upside, though, I already got a local response from a salvage yard and he's got a '90 RS that is supposed to still run (just has some front/side damage), so if I need some serious parts, it looks like I do have a source now.

As for the mechanic...I don't think they're idiots at all. They've actually got all the certifications I've been told to look for, nothing but good reviews and I've also got a coupon for free diagnostic time with repair, so anything I don't feel comfortable doing myself shouldn't cost me an arm and a leg, since I won't get charged for the diagnosing time. I guess he just wasn't aware that I'd restored the car and figured that since I'm a younger driver, I wouldn't want to invest the time and money in figuring out the problems.

Here's hoping I'm back on the road soon. Missing driving on all the nice, sunny days lately is driving me crazy.

 

Alright, update time, finally... My car is (finally!) up and running strong again! Due to lack of proper tools, know-how and a dry place to work, I took my baby to a shop, where a myriad of little annoyances were fixed: several bad connections, some vacuum leaks repaired, a couple shorted/blown fuses replaced, my sensor and it turns out I had a bad fuel injector. Total bill was around $310.00; shop told me my engine is running fine and there's no need to drop a new one in.

It's still at the shop, though, as I need a new steering column...not a big deal, though. There's a yard near me that's full of third gens. Should have my car back next week some time.

 

I've got a 92 chevy truck that ran great.then it started acting up and would hardly run until it was hooked up to check out.The ground in the computer must have been bad.couse I hooked a speaker wire from body of computer to body of truck and has run great ever sence.over 6 months now.try it!

 

Speaker wire should never be used for a permanent fix on anything but speakers. A small roll of stranded automotive wire can be had at most auto parts stores or even radio shack for less than $5.

 

ok,not a good way to do it.it was a test to start out with and I never got back to changing it to a larger gauge wire