Hard start / dies when hot.

[Sweepspear]

The latest gremlin to appear on my 1992 Park Ave. Non Supercharged w/ 63,000 miles, is a hard start, sometime stall condition when hot.

When hot, it has to turn over quite a bit to get the engine started. If I don't step on the throttle a little once it starts it will immediately die.

On 2 occasions, one of them being today, after I have been sitting stopped and idling, at a drive through lane at a fast food restaurant for example, when I let my foot off the brake and start to pull away the engine has died.
No hesitation, nothing, just dead.
Then, I go through the routine in starting it I mentioned above all over again and it will run fine.
Doesn't matter if the AC is on or not.

Maintenance items that have been done over the past year other than fluids.
New AC plugs.
New AC Plug wires.
New fuel filter about 90 days ago.
New coil pack and ignition module to correct a rough running / stutter problem.
At the time I was diagnosing the rough running / stutter problem, I tested fuel pressure and it was within spec at 45 lbs. (If I recall correctly)
No codes are ever stored when I check.

As a cheap, what the heck solution, I have run a can of injector cleaner through it.

Any ideas before I spend the money for a shop to diagnose it?
I am for the most part a do it myself guy and have both the mechanical & electrical factory service manuals for the car. Though, they aren't as layman friendly as they used to be.
The only thing I have used shops for in 31 years of driving is tire mounting and balancing.
But I digress.

Thanks in advance!

Dale

[Scrapper]

well i see you never had your maf sensor check.but when it gets hot a dies could even be your coilpack that sets on top moduler.

[Sweepspear]

Originally Posted by scrapper1

well i see you never had your maf sensor check.but when it gets hot a dies could even be your coilpack that sets on top moduler.

No, haven't checked the MAF sensor.
Both the coil pack & ignition module are less than 60 days old though.

[maxwedge]

The maf could cause this, so can the crank sensor.

[HotZ28]

You might want to try cleaning the MAF sensor wire with MAF cleaner before testing. Of course, a scan tool is the best method of testing. A full function scanner will show air flow in terms of grams of air per second (gps), with a range from 3gps to 150 gps. The MAF sensor produces a frequency output between 32 and 150 hertz.


The harness to your MAF sensor is three wires labeled A, B, and C. (it is that thing near the air intake area) It has a pink/black wire (C), a black/white wire (B), and a yellow wire (A). Wire C goes to a fuse in the relay center under the passenger side dash. Wire B goes to ground. Wire A goes to the PCM.

First thing: check the wires and harness for trouble.

Second: disconnect electrical connector, turn key to ON position, engine stopped. Read voltage between wire A and ground. It should be between 4-6 volts. Is it? If yes, connect test light between wires B and C. Light should be on. Is it? If yes, you have a faulty MAF sensor connection or sensor. If no, connect test light between C and ground. Test light should be on. Is it? If yes, the ground wire (B) has an open. If no, the pink/black wire (C) has an open.

If the voltage was not between 4-6 volts above:

If it was less than 4 volts, either the yellow wire (A) is open or shorted to ground, or you have a faulty PCM.

If it was more than 6 volts, the yellow wire (A) is either open to voltage or you have a faulty PCM.

[Sweepspear]

Originally Posted by HotZ28

connect test light between wires B and C. Light should be on. Is it? If yes, you have a faulty MAF sensor connection or sensor. If no, connect test light between C and ground. Test light should be on. Is it? If yes, the ground wire (B) has an open. If no, the pink/black wire (C) has an open.

I'm confused.
If in both cases, the test light should be on, and it is, that indicates trouble?
Did you mean to say the light should be on, but if it isn't that indicates trouble?
Can you clarify please?

Otherwise, you have given me clear directions for testing. I will check it out tomorrow.

I appreciate your help!

[HotZ28]

Did you mean to say the light should be on, but if it isn't that indicates trouble?
Can you clarify please?

Either way could indicate a problem!

Wire A goes to the PCM.
Wire B goes to ground.
Wire C goes to a fuse in the relay center under the passenger side dash.

Remember, you are checking for proper voltage going to the MAF sensor. If the voltage checks ok going to the MAF, then you have a problem with the MAF. If not, you have wiring, connector, fuse, or PCM problem. Read the instructions several times, for a better understanding of the procedure.

[Sweepspear]

Ok, checked it out.
Voltage between wire A & ground is 5.02 volts.
Test light between wires B & C results in test light being on.
Test light between wire C & ground results in test light being on.

The procedure made more sense to me when I found the flow chart in the service manual for it.

It also mentions the throttle position sensor binding, or having a high voltage signal with the throttle closed. "Should read between .33 - .46 volts @ 0% throttle angle."
Or, the coolant temp sensor.
What are your thoughts on these being the cause?
Is there a way to check these using a multi meter?

Man, I am surprised by how much a MAF sensor costs! About $140.00 for a rebuilt one with a $70.00 core.
Wish I had access to a known good one to swap out to be certain it is the cause before buying one.


I appreciate the help!

[Sweepspear]

Update.
My neighbor let me swap in the MAF sensor from his Olds 98 for test purposes, and what a difference!
Fires right off, and when idling at a light the engine is so smooth you would think it wasn't running.
Now I feel better about spending the money.

Thanks for all the help!

[HotZ28]

I was about to ask when you were planning to change the MAF! Anyway, we appreciate the feedback and I hope that this thread will help save others alot of time and frustration.

[doorunrun]

It's nice to have spare MAF; I found they are somewhat specific to the engine model. If you can match part numbers, all the better. I think they all start with AFH50M, but the last 3 digits indicate a certain engine application curve. And I'm sure that's why they cost so much.

I my situation, I tried using a MAF from a junked non-supercharged '3800 on my '92 PAU. The numbers were pretty close, when I used it on my supercharged engine, boy did I see performance problems....mostly under hard acceleration and a Code 57 popped up out of the blue.

I came across a listing on another forum as to what fits what; sorry, I don't have the link.

[Sweepspear]

I'll pay attention to the part # when I go to the yard this weekend.

I did notice that for an aftermarket sensor from Autozone for example, shows the same part # for both the Supercharged, and non supercharged.

I have a feeling they are calibrated (if that's the word) as a compromise between the 2, and not the way GM would have intended.

[doorunrun]

Below is the table I was referring to earlier..I did not send the original link for fear of "advertising" the site. This is probably easier anyway. BTW, it was a site devoted to Bonnevilles. Now, the original MAF on my PAU is a '02C. I pulled a '02E from the junkyard and had troubles. I thought I got one from a '92 but at this point who knows. Good Luck!

[doorunrun]

I guess I'm on a roll on this issue....I checked the AC Delco web site for the part and the MAF for a '92 PA is either 213-230 or 213-1619. For the '92 PAU the number is a 213-231 or 213-1620. I didn't check Rock Auto, but they're pretty good on the cross references. Anyway, be careful.
Also, at my junkyard the MAF modules seem to go quickly. There usually isn't one on any of the cars that have been there for a while. I hope you find one.

[Sweepspear]

Originally Posted by doorunrun

I guess I'm on a roll on this issue....I checked the AC Delco web site for the part and the MAF for a '92 PA is either 213-230 or 213-1619. For the '92 PAU the number is a 213-231 or 213-1620. I didn't check Rock Auto, but they're pretty good on the cross references. Anyway, be careful.
Also, at my junkyard the MAF modules seem to go quickly. There usually isn't one on any of the cars that have been there for a while. I hope you find one.

Yeah, I'm not sure I will find one at the yard, but what the heck?
Some yards pull parts like these and have them on a shelf.

But, I need to find a couple of other parts like the chrome bumper strips / trim that run along the quarter panel.
My car is in great condition except for these.
It was a little 'ol lady car with 30,000 miles on it 3 years ago when I bought it.
Why is it that on all the trashed & rusty Park Avenue I see, these chrome strips are in nice shape while mine have rust holes in them?

I haven't gone yard scrounging in a long time so I am looking forward to it.
So many yards I used to go to are long gone and housing developments now stand in their place.

Any ways, thanks for the info.
Was that site you mentioned the Pontiac Bonneville Club forum?