Railroadman

It's quite foolish (and expensive) to randomly replace stuff in hopes something will work. Get yourself the right manuals, some decent test equipment, and use logic and reason to identify the issue.

Don't just guess - find the smoking gun.

No Poker Champ

I am inclined to bel've its am electrical problem also / circuit. Its odd in that I replaced the MAF & TPS, as well as the ECM, MASS RELAYS, IAC, and even the fuel filter, I stopped replacing components when I did a fuel pressure test. (see other threads) And as you know replacing parts has become very expensive. The only code that I originally had was a code that the mass relays were bad, which replaced. Even when I put the original replaced components back in the car I get the same results. As you had suggested I will start the car, then connect the TPS or the MAF, the car will stall right away. Nor will it start with the MAF of TPS connected
Running out of straws...

nobodycls

You say that you replaced the MAF power and burn-off relays, and the tps. Did you correctly set the tps voltage at idle when installing it? Do you have the ability to read a wiring diagram and measure the tps return signal? I think this is where you should start, along with checking the wiring for the power and burn-off relays for the maf as well. A little bit of time spent searching on here will turn up some good pictures and procedures if you do not have access to a FSM.

JMelton

My 1988 project car wouldn't start and idle unless the MAF was unplugged.

I found that a shadetree mechanic prior to me getting the car had installed the 9th injector where it was pulled away from the intake causing a huge air leak.

Unplugging the MAF would let it start, but it sounded like crap. As soon as you plugged the MAF in, nothing, wouldn't run.

May not be what's causing your problem, but something to consider.

hooked073

you have a know problem that has a direct link to both the fuel pump and maf and you are not going to consider it. You night as well just replace part after part

hooked073

No Poker Champ

Yes, I did replace those parts and kept the od ones. I am definitely taking yours and others advise on measuring the currents of the components. In fact I purchased a reasonably good meter today, and will spend the next few days learning to read and use it.

hooked073

sorry if I come off as a dic? but the very very first thing you do when diagonising a problem is to fix the know problems first. now would you replace a burned out tail light for an engine miss no but use reason and you have a lot better chance of finding and fixing the problem fast and at the least amount of money

No Poker Champ

I really, really appreciate all your responses, and yes I know that I have been running around in my vett just putting out small fires. And you guys info has been truly important to me.
This is really my second vet. And as with my first one I was able to repair any aspect of it mechanically. But this electrical stuff was always a task I would not deal with. In fact, I would take a car with a bad engine or trans before taking on electrical problems. But you guys words are very encouraging. And you all are giving me the energy to keep trying out your suggestions. It also frightens me that I'm getting close to being upside down with this car, in terms of money invested. In fact, you guys words make it easier for me to come back each day to try a different avenue.

Thanks

No Poker Champ

No, I did not take offense to your comments. I've grown to consider myself a reasonably good mechanic. And it took a minute, but I soon saw that I was possibly running around chasing symptoms instead of looking for the problem. My rationale early on was it was a new car (to me) and any replaced parts gave me a bit of confidence in the mechanical stability of the car. (Meaning the parts replaced were a part of my investing in the car). When I saw I was running in circles I sought out you guys expertise. That being said, like many newbies that come here I / we just don't know. And what is reasonably simple to you guys can seem like brain surgery to us rookies.

That being said, I know that with you guys assistance I'm close to a break thru. And when it happens we can all sit down and enjoy a collective sigh...
Thanks

tunedport85inject

Poker here a good tutorial about digitalmeter how to.If you have some doubts read over this tutorial.
https://learn.sparkfun.com/tutorials...ter/continuity.

I have pics of code 33-34 and 21-22 from the FSM ,but my 85' is slightly different in this circuit and i would generate confusion.Some guys here will post 88 ' FSM code 33-34 and 21-22 for TPS low and high.

i advice you to pull the codes from your ECM , grounding pin A e B on ALDL connector under the dash .if ,as you told the problems start with the MAF and/or TPS connected then you have to go through the pages about the codes.with your patience and our collaboration we'll solve the problem

No Poker Champ

I want to truly thank all of the members who took the time to help me
with my corvette issue. I was definitely at my wits end. And I really got to learn a lot about the value of interest groups and my car.

My original post was about replacing everything from the rooter to the tooter. And it seems I did. After replace everything connected to the throttle body system (TPS, IAC, MAF found out the after market MAF was defective, BURN OFF RELAYS, FUEL PUMP RELAYS, FUEL FILTER) my car would start and run only when I disconnected the MAF and the TPS. When my car would start and run without those components, I foolishly discounted and accepted a low fuel pressure 25 - 30 pounds. So as you guys can tell, I walked away from my sweet corvette for a couple weeks. And came back and decided to go All In (a poker players term for putting everything in), and shell out another $75.00 on a fuel pump. What could be the worst thing that could happen right. Went out to Napa. Installed it. And BAM, MY BABY STARTED RIGHT UP. I connected all the components and let that sweet thing run for almost 45 minutes. I can't wait. Cause tomorrow after I get of work, she goes for a spin thru the neighborhood. To stop the neighbors from asking that pesky question, (with a hater's sneer...) "WHERE'S YOUR VETT". Now again its in their face, where the Corvette Forum says it should be.
Again thanks All