Dotren

Greetings all,

I've got a 1985 Iroc Z28 Camaro 5.0L 305 (should be VIN F I believe) and I've been having some MAF problems lately.

My original MAF was giving a code 33 and was bogging a bit on acceleration. Normally this seemed to smooth out after driving it a while but it would always accelerate oddly when first driving. I had it replaced but the first one we got caused the engine to constantly stall and run rich (black smoke coming out of exhaust). We got a second MAF replacement.. this one seemed to run terrific and there were no more codes other than an Oxygen sensor that is acting up after extended driving.

Unfortunately, less than a week later, I went to start the car in the morning and it was stalling and running rich again (same problem as the first MAF replacement). Again I got a replacement MAF and installed it.

The engine is running better again although it still feels like its hesitating when it accelerates but I'm getting a code 33 again as soon as the engine starts.

I've attempted to locate the MAF relay, which from what I've read should be on the driver's side firewall, but I can only locate what I believe is the fuel pump relay. I've attempted to trace some of the wiring from the MAF sensor with no luck so far (red wire seems to go into the front passenger side wheel well and from there into the body via a connector along with a mass of other wires).

Unfortunately I don't have a lot of high quality tools to troubleshoot this and after replacing the MAF sensor and a new radiator this weekend I'm starting to run low on funds. I'm worried that the MAF sensor I had that was good may have gotten burned out somehow from the vehicle and I'm not sure how much more swapping the shop I bought it from will do if it happens again.

Anyone have any advice?

Thanks!

305ho

iTrader: (1)

Need more info. Is your z manual or auto, carb or TPI 305

Dotren

It's a TPI automatic.

305ho

iTrader: (1)

I am working on it for you. Just made a call to a good a friend of mine that been working at GM since the early 80's stand by.

305ho

iTrader: (1)

Here is a list of Items to replace with part numbers, only use GM parts for this repair. After replacement unhook the battery for about 30 seconds to clear code or codes

SENSOR EXH OXYGEN
Replaced by: 19178953

17113483VALVE EGR (1985)

GASKET EGR VLV
Replaced by: 10077547

These two part numbers below are no longer available thru GM. Have the parts person do a search to see if another dealer might have these two Items still in stock. I am sure there is some where

14080620

MODULE MASS AIR FLOW SEN BURNOFF


1997111

SOLENOID EGR CONT VLV RLY (1985-86)(CPS)

Dotren

Thanks 305ho! Your help is greatly appreciated.

Are all of those parts related to the code 33? I was under the impression that 33 related to a MAF problem or a vacuum leak somewhere?

Thanks again!

305ho

iTrader: (1)

All these Items work inconjuction with each other and just because you have code 33 does not limit it to just the mass air flow. I have been in your shoes with my camaro dealing with check engine lights and running issues. I had just one code that pointed to the EGR but there was other Items which caused the EGR to fail. Replace what I mention and you will be good and running like NEW again. Just use GM parts NO after market parts when it comes to Emmission Items.

Dotren

Ok thanks again 305ho I'll see what I can do with the money I have at the moment.

This certainly answered one big question I was running into which was "where is the mass air flow relay and burn-off relay?". Apparently, from what I'm reading online, that 14080620 part is actually the equivalent of both the relays I was looking for, all part of one module which should be mounted to the ECM. I plan checking that out later today after it cools down outside.

305ho

iTrader: (1)

Good luck and just save up so you can repair your Camaro correctly. Other wise you will just keep replacing the same parts over and over. Keep me posted.

Happy trails

Dotren

Quick update.

I believe I've narrowed down the problem to the Burn-Off Module. After determining that replacement wasn't a very viable option (cheapest I found it was under $350 from NAPA but it's out-of-stock nationwide at the moment.. Vintage Parts apparently has some but they're over $1,000) I took the module apart and had my friend take a look at the board. We couldn't find anything overtly wrong with it so we plugged it back in and tested it out of it's box so we could observe the relay in action.

Sure enough, the relay functioned and no Code 33 occurred. Unfortunately, after putting it back together and re-mounting it I was getting the code again. After playing with it a bit we believe there is a short occurring, possibly due to a loose connection where the wires connect to the board or in one of the nearby plugs, or perhaps a broken wire that is making intermittent connection. When a test occurred where the relay did not function, moving the unit wiring around would cause the relay to suddenly engage.

I have the ECM and module sitting on my passenger side floor for now so that I can make adjustments to the wires should the code appear again until I can either trace the wires or have someone take a look at it.

**Edit**
I should also note that on my test drive when there was no code 33 the car ran great... no more hesitation on acceleration!

ASE doc

Im sorry 305ho, but how do we get to replacing the EGR valve for a code 33? Also, Dotren, good job on not going out and spending several hundred on parts because someone miles away, who's never even seen your car, told you to. Its irresponsible to tell someone to buy parts without testing and verifying that a particular part has failed. Im not that hot on spending others' money. That parts list is about $600+ worth. BTW, Im a GM engine performance specialist of 25 years.

The failure in your MAF module is probably a failed solder joint between the relay and the printed circuit board. You can verify this by looking closely at these connections with a magnifying glass. If you or someone you know is good with solder, you could repair it and save $350.

cIaRmOaCrZo

had this problem in my 86 for forever. buy new GM burnoff relay and maf relay ONLY. swap em out. theyr located on the firewall by the brake booster. theyr all side by side. at least they are on 86's.

ASE doc

The 85 is different. Relays are built into a MAF module. Its discontinued from GM, $350 from NAPA.

rednekwizard

My 86 keeps coming up with code 34, and fails smog because the hydrocarbons are way up there, I took out the mass airflow unit and ran the part numbers on it and only one supplier in the world carries it and they want over 700 dollars for it, I need help getting it fixed for smog testing so I don't lose it.

ASE doc

The 86 MAF controller is a one year only part. This makes it a rare part these days.

rbcobra666

i had the same problem throw code 33 randomly and get what felt like fuel cuts at low rpm, went down to autozone to see if i could get the burnoff relay they gave me some chinese part they said to try i did and for some reason havent had a problem yet but when i say its random it is pretty random so who knows.