OK, turned out to be the ignition coil. But I still get a MAF ses code. Says that voltage to high. Put in another one, reads voltage to low. WTF. Also, with the voltage low MAF sensors, the car wont stay running untill the ses light comes on. Any suggestions

Steve

 

Voltage issues (code 33 and 34) can have a bunch of different causes. If you do a "MAF" search on thirdgen.org you'll find a wealth of info on both.

Code 34s can come from the MAF, the ECM, or a relay. Code 33s can come from the MAF, from a mal-adjusted CTS, from the relay or from a PROM issue that was present on the earlier cars.

 

do u know what # the codes are? b/c in my car last week i had a code 33 and 36...i replaced the MAF Power relay and MAF burnoff relay and now i have no codes

 

Same here, replace the burn off then no code. But now it's back. Replaced all 3 relays (2powers and 1 burnoff) but this time it's still on. I think I got a bad burnoff. I'm going to replace it with a new GM relay. Jim85, you seem to be wise in teh relm of 3rd gen. I'll be there one day.

 

Trust me. Once you have as many problems as I have, you'll be wise too.

I remember all the MAF codes by heart because I see them ALL THE TIME. Right now I'm fighting with a code 33 in the IROC that only occurs when it's in the 40s or colder outside.

Anyway, a code 36 points to the burnoff relay (which some of you already knew) and not much else can cause it. It's possible for the burnoff circuit in the MAF to tank, but I don't think that will throw a code... it'll just cause the MAF to get full of crud and throw a 33 or 34.

BTW, only 2 of those 3 relays are MAF relays. The other one is the fuel pump relay.

 

Have you adjusted your throttle stop screw at all? The one that opens the throttle blades if you turn it on the drivers side of the TB? If so, that may be your problem. You can get an SES code from that because the source code has a "high error diagnostic" setting set at 45 grams per second. If the car sees 45 grams before the TPS reads a certain voltage the car thinks the MAF is reading incorrectly and will throw a code.

Jim, this goes for you too. I have the same problem as you, I need to readjust the set screw so the blades are open less and rely more on the IAC through tuning... which I still have yet to tackle.

 

BTW, only 2 of those 3 relays are MAF relays. The other one is the fuel pump relay.


Intresting bit of info. That means that my fuel pump is being "relayed" by a maf power. I'm sure they both probably do the same thing.

RedIroc, that makes sence. I have a bit of a weird idle too. I know the IAC has just recently been adjusted but I've also had the intake off recently as well. I could have thrown the IAC out of wack in the prosses. Thanks

 

I'm getting a very (VERY) noticable stumble when driving, so the code 33 is more than a mal-adjusted TPS. The MAF is having legit problems, which seems to be a bad contact which is only apparent in the cold. I think I'm getting an interrupted signal, which is what is causing the car to stumble and throw the code. Adjusting my TPS won't fix that.

BTW, my IAC issue is a botched abortion that I can't fix. I've set minimum idle a hundred times, changed the throttle body, IAC (twice) repinned the plug with new plastic and changed the ECM (twice). Still having IAC issues.

 

Jim, you have a modded motor right? Also, you do your own tuning?

 

I had a similar problem, turned out to be the MAF fuse near the fender well, a red wire and a yellow wire going to a seeming dead end.(On my '86 )

 

I'm not aware of a MAF fuse. That sounds like the ECM fuse from your description.

Yes and yes.

 

I'd also like to know of this MAF fuse.