92 buick park ave runs when it wants

Don't know what is wrong with this car. When it is cold it will start no prob. When it is warmed up it will turn over and over but no start. Fuel pressure is good. We have replaced about every sesor we can. When driving you have all the power till after about 30 miles then the car can barely move . Push on the gas and it is like there is nothing there, top speed maybe 15 mph. We are wondering if the ECU is bad or the ignition module. At a stand still on this. any help would be apreciated. Thanks.

What is the fuel pressure when this happens? Step one in the diagnosis and any check engine lite? Possible blocked convertor also, if no cel and fuel pressure is in spec at the time then do a back pressure test on the cat. As you have realized by now replacing random parts is both ineffective and expensive. Lecture over. Post back results of tests.

My bad the way I worded the orginal question. We have fuel pressure in specs. gone through all engine codes that were in the ECM. And we replaced the faulty sensors (only the ones that were bad after we tested them for their vlaues). We also did replace all vaccum lines as a precaution since we found a lot of dry rot through out them. After the car has been ran and we park it it is no start till it cools. Engine turns over but will not start. We checked for spark as we had good fuel delivery. Weak spark and intermitiant spark. So far we haven't got any new codes from the ECM just two that keep coming back 22,21. Both refer to TPS sensor which we replaced due to internal short. Codes stand for high and low voltage from the throtle position sensor.

Tap on the ignition module when the engine is running and see if it faulters. You might need to take it to the dealer\mechanic to get the computer scaned professionaly. Because you can't monitor in real time on how the engine is running with a cheap scanner. Nor the "paper clip" trick will help in this case either. I think it would be money well spent, instead of tearing you hair out to find the cause. One last thought - check the wiring all around the engine and the sensor terminal wires, and make sure none of them are damaged.

Remove the ICM and take it to Auto Zone for testing. I assume you have replaced the crank sensor?

well here is where we stand. Ignition module is bad . Has it tested and it faulted in 3 seconds. Replaced that starts right up. But still have a rough idle when it is warmed up. Then when it idles down it will chug and die out. Last night while I was searching for info I came across a thread that had a ECM reset to learn idle speed for engine. The procedure for it and now I can not find it. If anyone can point me in the direction of that I would appreciate it. It was for GM ECM's to learn a idle speed for the engine after reset. Thanks in advance.
:banghead: :puke:

Unless you disconnected the battery there really is no idle learn issue.

There are a few methods floating around, but this is the one used by GM techs.

Reset ECM by pulling the ECM fuse for a few seconds, or remove the negative battery cable.
With A/C turned off, start car and immediately put it in Drive
with your foot on the brake. If the car does not start initially,
keep trying WITHOUT putting your foot on the accelerator.
Let the car idle in gear for at least 5 and no more than 7 minutes.
Shut off the car for 10 seconds.
Start engine, place in drive and let idle for 5 minutes.
Shut off engine.
Idle is learned.

I adjusted the TPS to get it within spec. Unhooked batteries to reset the codes. Test drove to check operation. Engine ran good during test drive and had good power. It idled fine before the engine was shut off. Once I shut it off and tried to restart the engine didn't want to start without slightly pushing on the throttle pedal. When it did run it ran rough and misfired upon acceleration. At idle it would lope and die. Checked engine codes again. Had codes 15, 16, and 21. The check engine light is staying on all the time now and could not retrieve any more diagnostic codes. It wouldn''t return to diagnostic mode. Noticed that the engine temp was up to 220 and the engine fans would not kick in. Also noticed that there was .5 volts on the return wire of the TPS with

I adjusted the TPS to get it within spec. Unhooked batteries to reset the codes. Test drove to check operation. Engine ran good during test drive and had good power. It idled fine before the engine was shut off. Once I shut it off and tried to restart the engine didn't want to start without slightly pushing on the throttle pedal. When it did run it ran rough and misfired upon acceleration. At idle it would lope and die. Checked engine codes again. Had codes 15, 16, and 21. The check engine light is staying on all the time now and could not retrieve any more diagnostic codes. It wouldn''t return to diagnostic mode. Noticed that the engine temp was up to 220 and the engine fans would not kick in. Also noticed that there was .5 volts on the return wire of the TPS with the key out of the ignition. I am getting frustrated. PLEASE HELP.

Code 15: engine coolant temp. sensor indicating low temps, or your engine coolant sensor circuit is open.
Code 16: DIS (distributorless ignition system) circuit fault
Code 21: TPS (throttle position sensor) circuit open, or voltage out of range (more than likely high)
Your fans aren't turning on because the faulty coolant temp. sensor is telling the ECM that your engine is running cooler than normal running temperatures. Replacing the ECT should fix this.
You said you replaced the ignition module, but what about the coils on top? You can have them tested, or just replace them since you got a new module. If they test faulty, this may solve the DIS trouble code you got.

There are a few methods floating around, but this is the one used by GM techs.

Reset ECM by pulling the ECM fuse for a few seconds, or remove the negative battery cable.
With A/C turned off, start car and immediately put it in Drive
with your foot on the brake. If the car does not start initially,
keep trying WITHOUT putting your foot on the accelerator.
Let the car idle in gear for at least 5 and no more than 7 minutes.
Shut off the car for 10 seconds.
Start engine, place in drive and let idle for 5 minutes.
Shut off engine.
Idle is learned.

You have got to be kidding me. Please tell me you are kidding me. Everytime I disconnect the battery for any reason, I will have to go through all this?? Whoever thought not to have the engine idle speed burned into the prom so it doesn't have to to be reset all the time deserves to be shot. What happens if my battery dies on the road and I need a jump start? Will my engine not idle properly because the ECM forgot what it was supposed to be doing and possibly stall out leaving me in search of someone else to jump start me again??

92-95 3.8L VIN L CODES

15 Coolant temperature sensor signal indicates a temperature colder than -36° F for at least 4 seconds after the engine had been running for 2 seconds.
16 Charging system voltage was either below 9 volts or above 17 volts for 10 seconds.
21 TPS voltage was above 0.8 volts for 5 seconds when engine was running and air flow was less than 15 gm/sec, or the TPS voltage was over 4.8 volts at any time.

You need to check your alt output!

ok guys here we go. The darnest thing to be a problem that we overlooked. The water pump, no squeling, no rattling, no seepage.....NO PRESSURE. Top hose hot, lower hose cold as ice..hummm. Pinch the top hose no pulsing. pump was turning but not cicrulating the coolant! thermostat might have been good but we replaced it anyway. After we figured out the ECM was bad and swapped it out the engine ran great just kept building heat, no codes , also noticed the fans were not kicking in...humm. Water not getting to the temperature sensor in the radiator telling the fans to turn on . Once again no circulation, so we go after the water pump and replace it. BINGO water moving, fans kicking in, thermostat opening, engine not overheating! A buddy of mine who works for Freightliner came up with a explanation for the pump's actions. When the pump would get hot from running the impeller would expand just enough to sit on the shaft even though it is turning and not pump. Due to heat expansion the pressure holding on there was gone . We tested the theory by heating up the pump impeller to about 205 degrees after we had it out (no visible signs of damage) and turned it with a drill, held the impeller with pliers ... sure enough the shaft turned and the impeller stayed put easily. now ain't that intersting! It would cool down and grab. Car is now running great, slight lope in idle but nothing to be really concerned with. I just had to share this find. I have never seen anything like it. Thanks for all the help guys.

Wow, who would have ever expected something like that? Were you still running the original water pump, or was it a rebuild?

It was the orginal water pump . We talked to the owner we bought it from. He had a notebook with dates and milage for all maintence that had been done to it since he owned it, and he was the orginal owner! He even had the bill of sale and sticker in the notebook as well. Very detailed with all the repairs. He gave us the notbook and we added in all our repairs. Probally the most complete history on a car I have ever seen. The car is at 152,000 miles.

ebez1,
Just curious, did you replace the ICM & ECM?, I noticed in post 6, that you replaced the ICM and in post 14 you said you replaced the ECM also.

I have seen several water pumps with press on impellers fail, like the one you had. About five years year’s ago, we found one not pumping and it was later at night, (all parts stores closed) and we went for the JB Weld trick on the shaft and impeller. It worked, and that pump is still on the car today!! (Over 40K miles)


Glad to here you are getting the problems resolved. Unfortunately, a car with that many miles, will offer many more challenges for you in the future.
One thing about an older Buick, they will keep you active!!

Yuppers had to replace them both! Impressed by the longevity of the epoxy fix! The expoxy trick, I was eyeballing some marine epoxy I had there cause it was late, but not to late to get to a store. The ICM got so hot that the internal wire connectors sunk into the insulating gel and shorted out. Fried that . LOL. So then we replaced that (Had the new one tested also)((Recommended highly)) as it took 3 of them before one tested clear. Moved on to the ECM, when hooking up our code reader it started getting codes then the CEL stayed on(solid light) and would not go out, give any codes, nothing. Well a few scraped knuckles later that was done. Installed. Ran great. Then started to get hot again,fans were working but no flow, then we figured it out. Felt a bit dumb but a good learning experience. Thus the solution. Funny thing is in our family lol we have 2 PA 95, 92. Also Delta 88, 3 Le Sabre's 03, 00, 97. So much of what we learn is well applied. By taking care of my vehicles I have done well for mileage out of vechiles I have owned. 324,00 out of a Grand Am 91 Quad 4 engine , 4 door. And still traded that 2 years ago for 2200 on trade in.

92-95 3.8L VIN L CODES

15 Coolant temperature sensor signal indicates a temperature colder than -36° F for at least 4 seconds after the engine had been running for 2 seconds.
16 Charging system voltage was either below 9 volts or above 17 volts for 10 seconds.
21 TPS voltage was above 0.8 volts for 5 seconds when engine was running and air flow was less than 15 gm/sec, or the TPS voltage was over 4.8 volts at any time.

You need to check your alt output!


What's about those codes?
I just had my 94 PA Ultra in a shop to check out why the SES light is coming on. (Advance only reads 95 and later.) They read 3 and 4 digit numbers like PO131, PO171, PO1406. They charged me $500.- for an EGR and O2 sensor but the SES still comes on. Are you and I talking about the same diagnostic or obd codes?

With the conversion to OBD11 starting in late 94, you will have some 94's with an OBD1 PCM and a 16 pin OBD11 ALDC connector. Some would read OBD1 codes (commonly referred to as OBD1.5) and others would read OBD11 codes. All vehicles after 96 are OBDII, and require a scanner to access them. Look under the hood at the sticker for emmisions and you should see that it is OBD11. The OBD1 & OBD11 codes are listed in the links below;
service engine soon (http://www.geocities.com/dann8785/serviceenginesoon.html)
Diagnostic Trouble Codes (http://autorepair.about.com/cs/generalinfo/l/bl_dtcs_main.htm#1985)
By the way, if I paid 500 bucks to get the codes cleared and using some parts that might not have solved the problem, I would be back at the shop asking questions about why I still have codes. They need to see if the codes are the same as before.

What's about those codes?
I just had my 94 PA Ultra in a shop to check out why the SES light is coming on. (Advance only reads 95 and later.) They read 3 and 4 digit numbers like PO131, PO171, PO1406. They charged me $500.- for an EGR and O2 sensor but the SES still comes on. Are you and I talking about the same diagnostic or obd codes?
Code PO131 = Upstream heated O2 Sensor circuit low voltage (bank 1, sensor 1)
Code PO171 = System Adaptive fuel too lean
Code PO1406 = Sorry, can not find that code in my books
The top two codes are actually 5-digit codes,PO is included as digits in the code. Dont know of 6-digit codes.
Ouch you paid a price for that! The O2 sensor is about $20 at O'reilly'sfor a Master Pro brand Takes about 15 mins to swap out. I dont see why the EGR valve was replaced. What was the car doing? Sounds? Temp? Running condition?

Are you sure that you had a P1406, or could it have been P1404?
Listed below are the 1404 & 1406 codes. It looks like GM only uses the 1404.
P1404 EGR Closed Position Performance (GM)
P1406 Heated Catalyst Internal Control Module Checksum/ROM Error (BMW)
P1406 DPFE Downstream Hose Off Or Plugged (Ford, Mazda)

With the conversion to OBD11 starting in late 94, you will have some 94's with an OBD1 PCM and a 16 pin OBD11 ALDC connector. Some would read OBD1 codes (commonly referred to as OBD1.5) and others would read OBD11 codes. All vehicles after 96 are OBDII, and require a scanner to access them. Look under the hood at the sticker for emmisions and you should see that it is OBD11. The OBD1 & OBD11 codes are listed in the links below;
service engine soon (http://www.geocities.com/dann8785/serviceenginesoon.html)
Diagnostic Trouble Codes (http://autorepair.about.com/cs/generalinfo/l/bl_dtcs_main.htm#1985)
By the way, if I paid 500 bucks to get the codes cleared and using some parts that might not have solved the problem, I would be back at the shop asking questions about why I still have codes. They need to see if the codes are the same as before.


I just came back from the shop, watched them hook up a scanner under the dash. Again PO131, PO171 and a new PO123. PO1406 (EGR) was gone.
These codes were located in system section "memory", the "current" section
was empty even though I drove up with the SES light on.
So can I assume that I have a OBD11 PCM? There is no emissions sticker anywhere, perhaps because we don't do emission tests?
And what about not reading a "current" error when the SES is on? -Was on before I turned the ignition off!
The specialists scratched their heads -and other body parts- and promised to call me after some research.

Code PO131 = Upstream heated O2 Sensor circuit low voltage (bank 1, sensor 1)
Code PO171 = System Adaptive fuel too lean
Code PO1406 = Sorry, can not find that code in my books
The top two codes are actually 5-digit codes,PO is included as digits in the code. Dont know of 6-digit codes.
Ouch you paid a price for that! The O2 sensor is about $20 at O'reilly'sfor a Master Pro brand Takes about 15 mins to swap out. I dont see why the EGR valve was replaced. What was the car doing? Sounds? Temp? Running condition?

Actually, none of the above.
I don't know if it is related, but I had them swap the charger with my standby so I could rebuild the original.
Some when after that the trouble started, the SES light came on, that's all.
I always had some knocking when accelerating under load and since the EGR
was never changed under my ownership I aggreed to replace it. They told me
1406, since the EGR is replaced now and the code is gone I can not confirm that. I found out later that the EGR sells for about $150.-.
There is no obvious drivability problem as far as I can tell. Had no chance yet to test accelleration under load.

If the PCM is spitting out PO codes, it is OBD11 and the PCM should be located under the hood. Did the shop clear all the codes again? What is the problem with the car other than a SES light? Skipping, surging, poor idle, or poor performance? You may have a PCM going bad!

P0123 = Throttle/Pedal Position Sensor/Switch A Circuit High Input

If the PCM is spitting out PO codes, it is OBD11 and the PCM should be located under the hood. Did the shop clear all the codes again? What is the problem with the car other than a SES light? Skipping, surging, poor idle, or poor performance? You may have a PCM going bad!

P0123 = Throttle/Pedal Position Sensor/Switch A Circuit High Input



Yes, they cleared the memory, and on my way home the light came on again.
There is no obvious problem other than accelleration knocking (occasionally), but I had that for years, no SES light.
The supercharger was swapped recently (seal, coupler) so I could rebuild it.

I need to share this with you:
About 3 years agao I had the PA in a dealership for alignment.
When it was ready to pick up, they were not able to start the engine and concluded that the "computer" was bad. They replaced it, all was ok and I got a bill for alignment and computer, $600.- if I remember right. I tried to argue that the car was running fine when I brought it in and would not pay for a computer, but they refused to hand the keys over. At this time I had a repair insurance and they finally coverd it.

I am assuming that "computer" and PCM are the same thing?

Yes, they cleared the memory, and on my way home the light came on again.
There is no obvious problem other than accelleration knocking (occasionally), but I had that for years, no SES light.
The supercharger was swapped recently (seal, coupler) so I could rebuild it.

I need to share this with you:
About 3 years agao I had the PA in a dealership for alignment.
When it was ready to pick up, they were not able to start the engine and concluded that the "computer" was bad. They replaced it, all was ok and I got a bill for alignment and computer, $600.- if I remember right. I tried to argue that the car was running fine when I brought it in and would not pay for a computer, but they refused to hand the keys over. At this time I had a repair insurance and they finally coverd it.

I am assuming that "computer" and PCM are the same thing?

Yes the "computer" and PCM is the same thing. I hate to suggest this once again; however, your shop needs to diagnose the problem using the codes. If they don't have any active codes and the SES light is still on, then it could be a bad PCM. I assume that the shop has a live scanner that can monitor all sensors input and output. You had a code that indicated a lean condition on one bank (3cylinders) and they should be able to find the reason for that! You said that you have a pinging in the engine. Do you run premium fuel in the car (93 octane)?

Yes the "computer" and PCM is the same thing. I hate to suggest this once again; however, your shop needs to diagnose the problem using the codes. If they don't have any active codes and the SES light is still on, then it could be a bad PCM. I assume that the shop has a live scanner that can monitor all sensors input and output. You had a code that indicated a lean condition on one bank (3cylinders) and they should be able to find the reason for that! You said that you have a pinging in the engine. Do you run premium fuel in the car (93 octane)?


Yes, the good stuff, always Ultra for the Ultra.
I once tried to have that pinging fixed, but the previously mensioned Dealership (a female associate) told me that there is really nothing they can do except changing out the engine. That was at about 95k miles. For obvious reasons I decided not to go with this option.
Since then and after browsing the forums I would assume that the knock sensor should prevent pinging in the first place and less than 93 octane should have no consequence other than less power.

But.... I wait what they come up with regarding the SES light. Perhaps a smoking gun overlooked for the last 5 years.

The knock sensor should pick up the ping and retard the timing. The amount of timing retard you would have is built into the “retard timing table” in the PCM. Usually it would range from 2-10 deg of retard. I was just wondering if the pinging started sometime soon after the dealer replaced the PCM? Not all PCM’s have the same timing tables and retard tables. The PCM would have to be specifically for the year and model car. The Ultra with the SC, would have a different fuel and timing curve, than the NA 3800 and would require a specific PCM program for that application. You should not have pinging under any conditions if the PCM program and knock sensor are correct and operational. Yes, lower octane fuel would cause a loss of power and some surging and bucking. The reason you would have a loss of power would be due to the timing retard when the knock sensor picks up a ping.

The knock sensor should pick up the ping and retard the timing. The amount of timing retard you would have is built into the “retard timing table” in the PCM. Usually it would range from 2-10 deg of retard. I was just wondering if the pinging started sometime soon after the dealer replaced the PCM? Not all PCM’s have the same timing tables and retard tables. The PCM would have to be specifically for the year and model car. The Ultra with the SC, would have a different fuel and timing curve, than the NA 3800 and would require a specific PCM program for that application. You should not have pinging under any conditions if the PCM program and knock sensor are correct and operational. Yes, lower octane fuel would cause a loss of power and some surging and bucking. The reason you would have a loss of power would be due to the timing retard when the knock sensor picks up a ping.


I do not recall if it was soon after, but I know for sure that I did not have (perhaps just did not notice) a pinging before.
How would I figure out if I have the right PCM?

http://www.aa1car.com/library/pcm.htm
http://www.aa1car.com/
http://www.carleysoftware.com/