You need to get the code, replacing parts is expensive, fustrating, and time consuming. I am sure you can fix this quickly with a code.

 

Pull whatever codes there are and report back. I have an 85 shop manual. We'll walk through the steps to diagnose.

 

Ok here are the new codes I just pulled this morning. Luckily I have the day off.

Codes: 32, 34, 42.

32 and 42 are new to me since last week when I checked.

 

Well this is a mixed bag of codes.

32 is an EGR system failure.
34 is Mass Air Flow signal voltage low.
42 is Electronic Spark Timing.

Let's start with Code 34 which is the easiest to check.

1. Clear codes. This is done by disconnecting the battery ground and then reconnecting.
2. Start engine and idle for 1 minute or until Check Engine light comes on. Turn engine off and leave ignition on.
3. Check for codes.
4. If there's no code, the problem is intermittent and we'll need to move to another list of possible problems. If Code 34 is present, turn ignition off and clear codes. Disconnect Mass Air Flow sensor. Start engine and run for 1 minute or until check engine light comes on.
5. Check for codes.
6. If Code 33 is present, either the MAF is faulty or the burn-off circuit. If Code 34 is present, there is either a short to ground on the 5V reference circuit from the ECM or the ECM is faulty.

 

I'll do that now and update within the next 20-30 minutes. Thanks.

 

Ran the test and got a 34 so I continued. Unplugged the MAF and got 33.

This makes no sense, I have a brand new MAF and relay/burn off. This was the topic of another thread that lead me to where I am now... my issues the whole time were a faulty reman MAF, and I ended up getting a new one which works fine now... when it wants to (aka warm outside.)

On a side note, I think the 42 might have been my failure to clear codes after I reset my timing about a month ago. The 32 is beyond me.

 

Get the wiring schematic and find check the continuity of the wires to the MAS. There are only 4 wires, check each of their connections at their ends and make sure you have continuity in each wire and no shorts to ground, in any wire except the ground wires. A FSM would really be usefull or a Howell TPI book.

Code 32 is EGR and after you get code 34 figured out you will have to trouble shot that issue.

 

Do you know the numbers I should expect while checking the wires with a volt meter? I checked the green wire at the MAF a little while ago and it came back with the number a member gave me, already forgot it.

The ones at the MAF and relay will be a no brainer to check, but I cannot reach the wires that go to the firewall and behind the engine to the ECM.

 

Don't give up yet. The good news is that this is not an intermittent problem.

You replaced the burn-off power relay, not the burn-off module. The module is a metal box located behind the bread box on the dash. You need to verify the burn-off circuit is working. Try this test of the circuit. You will probably need someone to help.

1. Disconnect the front clamps on the MAF that hold the MAF to the air intake. Position the MAF so that you can see inside it.
2. Turn the ignition on.
3. Ground the serial data line on ALCL terminal E.
4. Turn ignition off.
5. Within 4 seconds the internal MAF sensor wire should start to glow. If it doesn't, there's a problem with the circuit or the burn-off module. There's another list of steps to figure which it is.

 

Please explain.

Are you saying to connect "A" and "E" on the diagnostic plug?

 

If that was the correct procedure with "A" and "E" then the MAF didn't start to glow anywhere. A neighbor came over and confirmed when I did it a few times.

What's the next step?

 

Exactly.

 

Do you have a multimeter?

 

Yes, I do. Give me the steps and I'll set it up now.

 

OK. You're going to check for 12V power from the burn off module to the MAF sensor.

1. Disconnect the MAF sensor connector.
2. Connect the voltmeter to terminal E and terminal A of the MAF sensor connector. Terminal E is a red wire. Terminal A is the larger of the two black wires.
3. Turn ignition on for 10 seconds.
4. Turn ignition off and look at voltmeter. You should see 8-10 volts for 4-8 seconds. If voltage drops immediately the burn off module is bad.

 

I'll grab lunch and try it out.

Thank you very much for the info so far, you've been very helpful. I'll send you an add for future reference hahaha.

 

Just tested the voltage and I got about 12.4v with ignition on, and it stayed there for about 6 seconds after the ignition was off. Tested both black wires and got the same reading, if that means anything.

 

OK. Now move the voltmeter from terminal E to terminal D (Blue wire). With ignition on the voltage should be less than 1 volt.

 

This still screams of WIRE HARNESS !

The egr code....inspect the wire in the thermal-time switch by the dist...if its loose, twist it around and try to get a better contact. These are good for causing the code. The ONLY other things that can set this code are the solenoid itself and/or the wire to/from.
Usually its the switch.

Look at the condition of the big bulkhead connector behind the pass side valve cover. Great place for damaged wire to short each other...cross signal etc.. Use air to blow crud off...its too fragile and too hard to get to for repairs. Avoid chemicals on that thing...

If you can, start it, and do some harness wiggling around...gentle but big pulling and tugging on different sections and listen closely to the engine. It will tell you immediately if you have stumbled onto the harness fault. The eng sound will have a subtle change in tone...The primary point of failure is the trunk line on the firewall under the wiper motor. This section has a bunch of very cheesey splices and it also is where the most critical grounds drop out to the bolt by the oil filter or whatever the grounds are attached to...trans, block, whatever. Jumper post as well. If those are dirty it will do the same things...all wrong.

These are ALL eng control systems and the splices corrode and/or the insulation cracks and cross signaling takes place. I had the intermittent misfire and in general PP engine performance for months until one day when I grabbed a handful of the harness and jerked it trying to see behind the driver side valve cover....the engine suddenly smoothed out and ran right at idle for the first time in months ! After some more exploring..I ended up hacking the whole driver side of the harness out and replaced it with new wire soldered in, all new plugs to inj and sensors...and its been trouble free since. The problem originates from a very poor grade of wire that had insulation that was NOT appropiate for automotive use. GM DID have service bulletins about this in the early 90s IIRC...the Gov even got involved because the wire and harness are supposed to have a minimum life expectancy to meet federal guidelines...and this did NOT meet the minimum.


Hope this helps, I've been there done that. Know how frustrating it can be. You'll get it...patience is the key,. You already KNOW you will solve the problem simply by the fact that you are addressing the issue. The question is..when, how long and whats it gonna cost?
You;ll get it. Your "team" is here to help.

good luck !

This is without a doubt...
the best support group I've run across since I learned the 12 step.....(not dancing..)

 

At this point, we have a MAF error code. The FSM points to either the MAF or the burnoff circuitry. He's just about done checking the burnoff circuit. The key here is that the MAF sensor wire did not glow in the diagnostic mode. So it's either the signal/power to the MAF or the MAF.

I suspect the EGR code could be related. The ECM uses the MAF signal along with others to control the EGR. The MAF signal could have triggered an EGR code.