redrider2911

K, so im working on my uncles 91 rs with the 3.1 v6 in it. Originally overheated once but then more problems arised. He took it to a shop and they told him that he had blown head gaskets and wanted a ridiculous amount of money to fix it. So he had me look at it. Jeeps are more my thing but whatever.

I drove it, it would sit right at 240 according to the gauge. Not more not less, just idled there no matter what. I thought it what strange. Started poking around. The electric fan wasnt kicking on. Strange... I jumped it at the plug and the fan worked. Fuse under the dash was fine. So I started it up and still the gauge read the same. I decided to get an infared gun. Engine was only at 210 or so at the thermostate housing.

So first problem. Gauge is reading wrong. The previous mechanic said he replaced it so is it a bad cluster? And the fan still doesnt kick on.

2nd (bigger) problem. In the middle of trying to jump the fan relay. I accidentally jumped the fuel pump relay and across wrong wires and I think I may have fried the PCM... I can jump the red wire and the pump kicks on. The car starts and revs up but doesnt idle. WHY? WHAT DID I DO?

Thanks for any help. Sorry for the long winded story.

redrider2911

Any help guys? Im supposed to give the car back with less problems not more! lol

camaronewbie

Wiring diags might help: http://www.austinthirdgen.org/index.php?pid=19

redrider2911

Yea I saw that. Thanks though. I think I may have crossed the red or orange wire with the dark green wire running from the PCM. Not sure, like I said, accident. Could that fry it? Is there an inline fuse before the computer?

james.gould150

i ould go to a junkyard and spend the hundred bucks and install new computer(very easy to do) also this gen camaros are NOTORIOUS for gueages (speedo,temp,tachetc.) being off most of the time slightly but ive seen them out quite a bit...maybe you can help me im kinda new and dont know how to start my own threads how do you do it?

redrider2911

Red white and blue button above the blue bar that says threads in this forum. When you are viewing the "tech/general engine" area.

camaronewbie

The ECM sends a 12v+ signal to the fuel pump relay, so shouldn't be a problem.

Fuel pump relay has

orange 12v+ always
black ground always
green/white 12v+ signal from ECM
grey (or tan/white on some) 12v+ out to fuel pump
red a wire that runs to a connector that GM techs used to prime pump - not important

So, with black having ground, and orange getting 12v+, when you apply 12v+ to the green/white wire, the relay will click and connect the orange wire to the grey (or tan/white in some cars) wire.

redrider2911

I just went out and did some double checking on things. The orange wire had no power. Jumped a wire strait to it from the battery and the relay and fuel pump seemed to kick on and "prime" like it should. The car started runs fine IF LEAVE MY FOOT ON THE GAS... Take my foot off and let it idle and it immediately dies. I dont understand what is happening.?

Also, where is the fusible link located in the orange wire? I think I crossed it with the black ground wire and melted it.

redrider2911

It seems like everything is working fine. I am feeding the orange wire constant power, the computer is activating the coil in the f/p relay when I turn the key on like it should, orange is connecting to gray. So why is it not idling?

james.gould150

first off thank you secondly you have to be extremely careful when jumping from the fusebox/aldl diog. terminal you can fry circuits in the ecm/pcm...try jumping the a and b ports with a paperclip in the aldl ...turn key to "on" but dont start the engine...if you dont get code 12 3 times in a row then you fried something in the ecm/pcm...your cel or sel light will be what flashes out your codes 12 is flas pause flash flash...hope this helps

redrider2911

Where and what is the aldl? lol

james.gould150

aldl is the obd1 terminal ... most if not all gm cars before 96 have them...its is located under the dash on driver sside (at least on my 91 z28) but as far as i know its all gm obd1 cars...its got 12 terminals i think? look up threads for diagnostic to find more accurate info...if i find a thread or link ill post it for you

redrider2911

Found it. I got code 12 three times! so good news right!? but now what is the problem? lol

redrider2911

It had like 12 ports in it but only 6 or something connectors in the ports. I jumped the top right 2 together.

james.gould150

sounds right to me(as far as diog.) as far as the computer and your issue i havent a clue(sorry) im having similar issues with my z28...the fans dont engage but when jumped they work fine...payday im going to replace the fan switch (on my v8 its on the fromt of the pass. side cyl. head) dunno if it will work ive been plagued with electrical issue since i bought the car a month ago...all i can suggest is when its running(cold and at temp) smell for that sweet pungeant familiar antifreez smell at the tailpipe...if you do it needs head gaskets for sure...like i said im no ace mechanic but i know a few things (not very familiar with electric issues) but i hope you can get it fixed..added note,some cars have the temp switch to engage fans at base of the radiator

redrider2911

Thats still my second issue. I can wire up an acc switch if I absolutely HAVE too. Now Im trying to figure out why it will all of a sudden start, run, rev up, but die immediately if I let off the gas

redrider2911

I out there and now it decides to run. lol These camaros are more frustrating than Jeeps! So now I need to find where the fusable link is for the orange 12v feed wire then deal with the fans tomorrow.

james.gould150

check/replace tps sensor might be the culprit for the reving n stalling issue they go bad and can cause similar issues...and be careful with fans the computer is very sensative with temp...if it is too cold it will send a signal to ecm and falsely adjust fuel/air ratio...yes these cars are a pain in the ***** with the electrical systems i wish i had the money to take mine somewhere and say just rewire and give me new updated EVERYTHING lol buuut not in the cards