96 DEVILLE CAR KEEPS STALLING

[GTHALACPUSHA]

HEY FELLOW CADI ENTHUSIAST

I HAVE A 96 DEVILLE AND IT HAS A STALLING PROMBLEM WHEN IM AT IDLE. I REPLACED THE MAP SENSOR,IAC VALVE, MASS AIR FLOW SENSOR AS WELL AS THE COIL PACKS AND SPARK PLUGS AND WIRES. BUT YET THE CAR STILL STALLS. SO I PULLED THE ENGINE CODES AND THE ONLY CODE THAT COMES UP IS PC1599 {NEAR STALLING). COULD IT BE THE EGR VALVE EVEN THOUGH IT DOESNT SHOW IN THE CODES?? WHAT COULD IT BE?? I REALLY NEED HELP ON THIS GUYS.

[Cadillac Jim]

Did you pull all the codes through the HVAC buttons and the driver display near the speedometer? If you used a code reader instead, look at the link in my signature block and use the car's built-in capability to display *all* the codes.

If any of the parts you have bought had caused a problem, there would have been OBD II codes. If it's stalling and there are no OBD codes, that in itself narrows things down quite a bit. The possibilities that occur to me are fuel pump, fuel filter (water in the gas?), and FPR. If it's the FPR, you will probably have hard starting when the car is hot as an additional problem. You can check the FPR by popping off the beauty cover over the intake manifold, pulling the vacuum line off the FPR, inspecting it to see if it is visibly leaking, and sniffing to see if gasoline is leaking into the vacuum line. If it's the fuel pump, you can check the fuel pressure and see what's up there.

[Ranger]

When is the last time the TB was cleaned?

[GTHALACPUSHA]

When is the last time the TB was cleaned?

I CLEANED THE THROTTLE BODY CAUSE IT WAS CAKED UP WITH CARBON BUILD UP AND THA MADE SOME DIFFERENCE BUT IT STILL HAS THE SAME SYMPTOMS

[GTHALACPUSHA]

Did you pull all the codes through the HVAC buttons and the driver display near the speedometer? If you used a code reader instead, look at the link in my signature block and use the car's built-in capability to display *all* the codes.

If any of the parts you have bought had caused a problem, there would have been OBD II codes. If it's stalling and there are no OBD codes, that in itself narrows things down quite a bit. The possibilities that occur to me are fuel pump, fuel filter (water in the gas?), and FPR. If it's the FPR, you will probably have hard starting when the car is hot as an additional problem. You can check the FPR by popping off the beauty cover over the intake manifold, pulling the vacuum line off the FPR, inspecting it to see if it is visibly leaking, and sniffing to see if gasoline is leaking into the vacuum line. If it's the fuel pump, you can check the fuel pressure and see what's up there.

YEA I CHANGED THE FUEL PRESSURE REGULATOR AS WELL AND THAT HELPED SOME AND YES I DID PULL THE CODES FROM THE CLIMATE CONTROL. ALSO THE CAR ONLY STALLS WHEN ITS HOT (TEMPERATURE WOULD BE AROUND 220)LIKE WHEN I WAS IN THE DRIVE THRU AND THE AC OFF FOR ENGINE PROTECTION MESSAGE CAME ON THEN A LIL WHILE LATER IT STALLED. AND IT MAINLY TURNS OFF WHEN IM AT IDLE IN GEAR OR PARK WITH THE AC ON HI COULD IT HAVE SOMETHING TO DO WITH MY COOLING SYSTEM? LIKE HEATER CONTROL VALVE OR THERMOSTAT CAUSE THE CAR IDLE ROUGH BUT RUNS GREAT ON THE HIGHWAY

[Cadillac Jim]

Could you please write down the OBD codes and post them here?

Would you mind to take the trouble to post in lower case? Posting in ALL CAPS puts some people off.

[GTHALACPUSHA]

Could you please write down the OBD codes and post them here?

Would you mind to take the trouble to post in lower case? Posting in ALL CAPS puts some people off.

the codes are pc1599 ac1350

[BodybyFisher]

Welcome Aboard

It only happens when it is hot you say

I would check fuel pressure when this happens. Its going to sound crazy, but I would tape a fuel pressure gage to the windshield (this technique was recommended by a Northstar powertain engineer), and watch the gage next time it stalls.

You are not getting any codes that make the problem obvious, other than the obvious after the fact P1599 stall code

So I think fuel problems when this happens, check fuel pressure, it could be the pump crapping out when its hot, a relay, etc Report to us the fuel pressure with the key on, engine running and with the key then off, how long does it hold

You are also getting an C1350 and ENGINE COOLANT OVERTEMPERATURE, that's a new one on me, Ill need to look that up, but, its in the HVAC area of DTC codes and I can only think its the PCM shutting down the AC due to high temps at about 260, I believe. Have you seen any messages about the AC being shut down?, or high engine temps?

Also consider this, when the AC Compressor hub bearing goes bad, sometimes, it will bind and stall the engine at idle. Is your engine stalling at idle?

Check all connections at the Ignition module, one of the connections supplies 12 volts and if it is disconnected the car will not start, so, if that connection is intermittant you will stall.

Finally, if none of those ideas pan out, you should tap test the PCM or at the very least, swap in a known good PCM. We have seen some PCMs that act wacky when they are hot, but act find when they are cool

Let us know how this works out

[BodybyFisher]

Just for fun, have your battery load tested, and make sure the connections are clean and tight

Watch your volt meter carefully for awhile to see if its fluctuating wildly or what your charging rate is

If you have a scrap yard near you, buy an ignition module and swap it in

And find out why you are overheating, pronto

[BodybyFisher]

And YES, all CAPs is really annoying as its hard to read

[Cadillac Jim]

B1350 Engine Coolant Over-Temperature

P1350 Ignition Control System

P1599 Engine Stall or Near Stall Detected

I'm going to guess here and say that the ignition module connector is loose or dirty. I think that "ac 1350" is P1350, not B1350, because the engine coolant code would be accompanied by other codes and messages like "CHANGE OIL NOW" and such.

When you start to run the codes, all the dash lights turn on for a few seconds as a bulb check. Also, when you turn the key on but the not to Start, the "Check Engine Soon" light comes on, but goes out; when you turn to Start, all the rest turn on for a second or two.

Are any of the bulbs out? Are there any warning lights lit once the engine is running for a few seconds?

If the codes are History, not Current, and you can clear them without them coming back quickly, the most likely things are water in the gas, the FPR and the fuel pump.

[BodybyFisher]

I think you are right about the 1350 Ignition Control System code Jim, because of the stalling, I picked up the wrong code

[GTHALACPUSHA]

Welcome Aboard

It only happens when it is hot you say

I would check fuel pressure when this happens. Its going to sound crazy, but I would tape a fuel pressure gage to the windshield (this technique was recommended by a Northstar powertain engineer), and watch the gage next time it stalls.

You are not getting any codes that make the problem obvious, other than the obvious after the fact P1599 stall code

So I think fuel problems when this happens, check fuel pressure, it could be the pump crapping out when its hot, a relay, etc Report to us the fuel pressure with the key on, engine running and with the key then off, how long does it hold

You are also getting an C1350 and ENGINE COOLANT OVERTEMPERATURE, that's a new one on me, Ill need to look that up, but, its in the HVAC area of DTC codes and I can only think its the PCM shutting down the AC due to high temps at about 260, I believe. Have you seen any messages about the AC being shut down?, or high engine temps?

Also consider this, when the AC Compressor hub bearing goes bad, sometimes, it will bind and stall the engine at idle. Is your engine stalling at idle?

Check all connections at the Ignition module, one of the connections supplies 12 volts and if it is disconnected the car will not start, so, if that connection is intermittant you will stall.

Finally, if none of those ideas pan out, you should tap test the PCM or at the very least, swap in a known good PCM. We have seen some PCMs that act wacky when they are hot, but act find when they are cool

Let us know how this works out

yea the ac off for engine protection came on and the connections are fine and it cuts off when the air is on as well

[GTHALACPUSHA]

B1350 Engine Coolant Over-Temperature

P1350 Ignition Control System

P1599 Engine Stall or Near Stall Detected

I'm going to guess here and say that the ignition module connector is loose or dirty. I think that "ac 1350" is P1350, not B1350, because the engine coolant code would be accompanied by other codes and messages like "CHANGE OIL NOW" and such.

When you start to run the codes, all the dash lights turn on for a few seconds as a bulb check. Also, when you turn the key on but the not to Start, the "Check Engine Soon" light comes on, but goes out; when you turn to Start, all the rest turn on for a second or two.

Are any of the bulbs out? Are there any warning lights lit once the engine is running for a few seconds?

If the codes are History, not Current, and you can clear them without them coming back quickly, the most likely things are water in the gas, the FPR and the fuel pump.

theres no warning lights either or service lights and how do you clear all the codes?

[Cadillac Jim]

The process for clearing the codes is available from the same process that you use for reading them. Be very careful because you are executing the process for programming your car's computers.

Press <Off> and <Warmer> simultaneously as when reading codes; all the lights will come on for a few seconds then go off, and the codes will begin.

Press <Fan lower> to skip the code readout, unless you need to read them to make a list. You will have a prompt "PCM?"

At this point, I will show how to clear the PCM codes, the ones that are of the form Pnnnn, where nnnn is four numerical digits.

At the "PCM?" prompt, press <Fan Higher> to get into the PCM programming.

Press <Fan Lower> repeatedly until you see "Clear Codes?" then press <Fan Higher>

After you get the "Codes Cleared" prompt press "Info Reset" to exit the diagnostic mode.

For other modules, when you get to the prompt "PCM?" then press <Fan Lower> to go to the next module. The modules will come in order. A typical order will be PCM, IPC, ACM, SDM, TCS, PZM, IRC, RFA, CCP, MSM, MMM, etc. Different years and models will have different modules. When you get to the module where you want to clear the codes, press <Fan Lower> to enter the programming mode for that module.