hi, on my Iroc I went to start my car and it wouldn't idle. so i unplugged the MAf and bam it starts right up and goes. so I figure okay time for a new MAF. so i got 3 used ones to try out on it and they had previously been tested on another Iroc and were working on that one just fine. so i hooked them one by one up to mine and the car wouldn't start but when i unplugged them it cranked right up, what the heck is going on? any help is as always greatly appreciated.

 

Is your CEL on (as in any trouble codes set)?

Also, is the engine stock or modified/hacked?

 

the CEl has always been on, and its not the cars stock engine but its a stock 350 from a trans am with the right chip as well. ive had it in the car for about 2 years now. the only mod is headers.

 

With a new motor, you'll have to start from SCRATCH. Absolutely from SCRATCH.

Your ECM needs to be completely re-written, and probably some of the harness connector pins' sockets will have to be re-pinned. If the motor came from the same year model, it will help a LITTLE.

You'll need FSM's for YOUR car, AND for the DONOR car (for the motor's sensors).

I re-pinned a front panel 7-pin connector for a desktop computer once, for Start, USB, and SD/MMC port connectors.

I DO NOT want to do it again.

 

really? I just put my intake on it and just spliced it it in. whats the FSM?

 

yeah and up until now that MAF has been working fine so now is it rejecting a new one?

 

Factory Service Manual;
the bible you should own unless you like paying out $$ or guessing what your problems are


So the obvious thing to do would have been to pull the engine codes and see what is causing the light.

A code , say for the MAF means a fault somewhere in the whole system; power , connections , grounds , wiring , etc; not just that the MAF itself is faulty.

If you owned the FSM for your car you could work through the fault flowcharts to identify what is actually wrong ;
instead of just throwing parts at it and hoping for the best

 

He states
"stock 350 from a trans am with the right chip as well".

 

well i should rephrase, the motor came out of a 91 trans am that was setup for speed density, so i had to take the chip from a 87 iroc with a 350 cuz it was MAF. so its a 350 chip that matches my ecm.

 

Once the computer is gone it makes no difference what system it was before.

 

well so what could be wrong then? i would like to get my MPG back up again lol

 

Find out why the SES light is on for starters.

Light only comes on because the computer is trying to TELL you you have a problem somewhere.

 

Well, maybe not ALL that, but, if if there's a DTC code for some sensor's CIRCUIT, you might find that the ECM is looking for something that was on the donor car (or donor cars' motor), and NOT on your car.

With motor swaps, even if the donor motor is PERFECTLY tuned, you can have circuit incompatibilities, that will cause nightmares with the OEM hardware.