I'm fixing my a/c (never had it work since I've had my car.. 5+ years)... and I replaced a few things and its not quite working right. The "high" setting on the flow deal on the left makes it stop, but I did a search and might have found out what is doing that....

..anyway... I have this blue wire that has one of those grip washers on it. Its on the passenger side of the motor in the back. Its coming out of the big wire loom and its taped up to the wire loom.

I wipped out my Haynes book and the only wire that I can find on the car that is a blue ground is for "(grounded w/ heater only)" BUT it says 3.1L V6. My car was not wired like a 90-92 car. Its got the stock 2.8L stuff on it.

When I grounded the wire while the car was running, the car stumbled and ran a little rough for a few seconds. Weird. It is right next to the blower motor, and I would think it should be grounded there considering it reaches right there, but I'm not 100%

I'm gonig to get a pic in a few min....

Any ideas?


-Bud

 

Knowing what year & model it's in would help.

 

His signature where it says "88 Camaro 3.4" might help with that

 

yea.. lol... its an 88.

As far as I know its the original wiring for the car... but when I tore my motor apart it turned out to be a 3.1 crank (I assume the shortblock was 3.1). It's still MAF and all that, so I'm almost 100% positive its the original stuffs.

Pic:

 

oh yea... all the blower motor speeds work like a champ and all the vaccum settings work also.

Still no idea what the blue wire is for though.

I have a knock sensor plug too, but I didnt think MAF cars had knock sensors? It's not plugged in, but I got a replacement knock sensor to plug up the hole on the 3.4 block. If I remember correctly there was something in the way of it getting plugged in. Weird.

heh...

-Bud

 

Yeah, it might at that. TechSmurf, got thrown by the 2.8L comment he had in there.
I went out to my car (89 Iroc) and checked the wiring there, I found a light blue wire but it didn't have the crush terminal on it and I don't have my 88 manual at the moment.
Yep, MAF cars have knock sensors in them.

Going through my schematics, I have found that there is a ground in that loom. It is for the coolant fan and grounds near the right hood strut. Dig a little deeper in the loom and you may find where the wire has been spliced at some point.

 

... or that might be why we had to wire my fans to my ignition b/c they didnt work maybe? lol. Guess I'll keep that wire taped up

back to the knock sensor though... I found the connector (or what I think is it), but its a green/white wire... not a blue wire like the haynes book says it should be...

Is this for sure it you think? Only plug that isnt plugged in and the knock sensor is the only thing not plugged in... and it reaches.... seems like it'd be a real big coincidence if it wasn't it...

 

The knock sensor wire on your car is dark blue, the green wire that you are holding up is for the coolant fan switch above the starter and slightly rearward of the knock sensor. The wires for those two components varies from year to year for some reason. In my 89 Iroc, they are black & white. Go figure!!!!!!!!!

 

How much worse would my car run w/out the knock sensor plugged in? I can't find that plug to save my life (not giving up though heheh)

Timing is set to ~10degrees @idle w/ that connector unplugged and it's stationary. My car has always run **** poor in the past (I dyno'd it w/ the old motor and put down 77rwhp and used to get like 12mpg around town), but its running its best now.. but it's still not a smooth hum, but then again I've never ridden in another thirdgen v6 so I dont know how smoothly they are supposed to idle either... gah

The car wasn't setting codes except for running rich (which I fixed hopefully.. we just tore the topend off and reset the valve lash and replaced a blown intake gasket).


-Bud

 

I'm thinking this is part of the problem...

Two dark blue wires spliced into one only ~6" from the computer....that's not factory is it...

 

Is that a solid uninsulated splice on that wire? if it is, that would be a factory splice. Does that wire go into the computer and if it does, what is the pin location?

 

It had some tape around it.
It connects #12 and #13.

There is also a wire that is a little darker of a blue that is #9.

 

Pin C9 is Fan Pressure Switch Input
Pin C12 & C13 are Throttle Position Sensor Input. BTW, that is a factory splice.

 

Those were the only dark blue wires coming out of the computer on that plug.. what pin# is supposed to be the knock sensor?

This is insane.


-Bud

 

Okay, I have to retract my wording on an earlier post although technically it is correct to a point. MAF cars for that year do have a dark blue wire for the knock sensor and a green wire for the coolant fan switch. However, this does not apply to the 2.8L engines of that year. This is because those engines did not have a knock sensor in them, only the 5.0L & 5.7L engines had them. Sorry for the mis-info.

 

I looked in the Haynes book and saw a knock sensor and the blue wire that supposedly came out of my computer. If I really dont have a knock sensor.. that's at least two things fairly recently that book has been incorrect about and caused mass confusion. Set the valve lash incorrectly according to that book too.

I think I'm just going to burn the book and buy a different one.

It's cool about the mis-info. I greatly appreciate the effort mang.


-Bud

 

Buy yourself a nice GM service manual for your car off e-bay. They are cheaper that way, that is where I get mine and they beat Haynes and Chilton in every way. Haynes and Chilton try to cover too many years and models and not go into detail enough about any of them.

 

800 pages of goodness will be on its way soon.

http://cgi.ebay.com/ebaymotors/ws/eB...&category=6761

Thanks a lot for all the info/effort again mang.


-Bud

 

Yeah, 82-89 2.8's shouldn't have any knock sensor! '67, that GM book you're getting will even have pictures in section 8 of where all the individual wires and wire looms go. The only thing you won't get is how the wire looms were run around the car... like, where they attached to framerails with clips, or how the alternator wire snakes under the motor- but you'll get a picture, for instance, of the rear right head, with a picture of a bolt and two ring terminals with wires going to it.

EVERYONE should have a GM manual by now!! Like Trickster said, the Haynes is good for a beginner, or if you want a standard procedure- like how to rebuild a master cylinder or drop out a transmission- any diagnostic stuff REQUIRES the GM book.

How'd you fix the high speed setting? Was it just the high speed blower relay, the high speed relay's fusable link, or that plastic connector on the HVAC controls?

 

I replaced that relay that is attatched to the plastic next to the blower motor. It was all corroded and dirty. You can actually see the new one hanging on the right side of the first pic... lighter in color...

Either that fixed it or it was a coincidence heheh. Either way high works now. I was thinking it was that red wire back there... I read in a post that wire has somehting to do w/ that, but mine was fine. Recharge the A/c and I'm good to go.

Time to put the dash back in tonight and continue work on the bumper/tail light

 

After I totalled my car and put it back together, I was never able to reattach the high speed relay to it's bracket (the plastic slide on the back of the relay snapped, and the bracket was bent to hell). So, I just let the relay hang. Well somehow water was getting in there, and rusted up the contacts! I had all speeds but high speed.

I popped the relay open, and everything was rusted inside. A few swipes with some 400 grit paper cleaned it all up, and this time I "hung" the relay so it sat upright.

But I was worried too about that HVAC wire, luckily, that wasn't the problem.