Engine stall Problem. Runs Fine then Dies.

[3800Regal92]

92 buick regal 3800 with engine stall problem. Will turn on and run perfectly, nice idle, can accelerate to redline no problem but only for 10-20 minutes and stall out at once although no signs of stalling occur( no noises or noticable RPM change). Just cuts out. Will turn on an hour later and run the same amount of time. Has tried new computer, oxygen sensor, Ignition control module, idle air controller, new plugs&wires,new thermostat,radiator flush, alternator checked, injectors checked, fuel pump checked, fuel pressure at rail is 32 psi... Still stalls everytime.

[bs009]

okay, sounds like you've done pretty well at narrowing it down.

32 psi. is pretty low as far as fuel pressure goes. It should be somewhere around 45.
Did you get that reading of fuel pressure after it dies or did you get it while it's running or did you get it before starting up? you may need to replace your fuel pump soon.

[richtazz]

Welcome to AF

I agree that 32psi is too low. Fuel pressure should be 41-44 psi, key on engine off, and with engine running and the FPR vacuum attached, it should drop 3-7 psi.

[Ruley73]

The next time it stalls pull an ignition wire off one of the coil towers and see if you have spark.

If you don't have spark, your crankshaft position sensor is probably bad.

If you have spark your fuel pump may be bad. FWIW there isn't a way to accurately test a fuel pump - they either work or they don't, but they can also become weak with age. Your fuel pressure is definitely low.

It is possible your fuel pump is weak (and should be replaced), but the engine is still able to run with 32 PSI and that your crank sensor is also bad.

Without knowing anything else, my guess is that your crank sensor is bad and causing the engine to stall due to the engine warming up the sensor and causing it to malfunction.

[3800Regal92]

i have been told that once the crankshaft postion sensor goes, the engine wont even turn over. That the problem is not intermitent and that i would not be able to start it up again.

june 18th 2009-Just ran it for a little over an hour and it did not stall out, however once I turned it off, It would crank and not start up. I tried it twice and it cranked but did not turn on., the third time I tried the engine would not even crank!! just total silence. listened for the fuel pump to actutate when i first turned the key and did not make a sound(the usual whirring of the pump was not there, indication of a somewhat bad pump, I think, i have the replacement motor and strainer at home).
I left for 15 minutes and when i came home I tried to turn it on. Now the engine will crank and turn but will not start??? I still did not hear the fuel pump come on and pressurize the fuel. I am going to change out the pump motor later this week...

.....but Why did the starter not even turn before when i tried to crank the engine?? That is baffling me because if it is a stand alone fuel pump issue then the engine should always crank and just not turn on, right?

Im going to wait another 30 minutes and try to crank it again, I'll listen for the pump first and see if it will turn on.

any help GREATLY APPRECIATED
Next update coming soon.....

[stripe]

Originally Posted by 3800Regal92

i have been told that once the crankshaft postion sensor goes, the engine wont even turn over. That the problem is not intermitent and that i would not be able to start it up again.

june 18th 2009-Just ran it for a little over an hour and it did not stall out, however once I turned it off, It would crank and not start up. I tried it twice and it cranked but did not turn on., the third time I tried the engine would not even crank!! just total silence. listened for the fuel pump to actutate when i first turned the key and did not make a sound(the usual whirring of the pump was not there, indication of a somewhat bad pump, I think, i have the replacement motor and strainer at home).
I left for 15 minutes and when i came home I tried to turn it on. Now the engine will crank and turn but will not start??? I still did not hear the fuel pump come on and pressurize the fuel. I am going to change out the pump motor later this week...

.....but Why did the starter not even turn before when i tried to crank the engine?? That is baffling me because if it is a stand alone fuel pump issue then the engine should always crank and just not turn on, right?

Im going to wait another 30 minutes and try to crank it again, I'll listen for the pump first and see if it will turn on.

any help GREATLY APPRECIATED
Next update coming soon.....

Wierd as it seems make sure your key is clean.

Also I would fill it with high-test gas.

luck to yah

Cheers
stripe

[richtazz]

Originally Posted by 3800Regal92

i have been told that once the crankshaft postion sensor goes, the engine wont even turn over. That the problem is not intermitent and that i would not be able to start it up again.

This is absolutely not true. The crank position sensor has nothing to do with the starter turning the engine over. A CKPS will also act up intermittently, failing when hot, and working again once it cools down.

Originally Posted by 3800Regal92

june 18th 2009-Just ran it for a little over an hour and it did not stall out, however once I turned it off, It would crank and not start up. I tried it twice and it cranked but did not turn on., the third time I tried the engine would not even crank!! just total silence. listened for the fuel pump to actutate when i first turned the key and did not make a sound(the usual whirring of the pump was not there, indication of a somewhat bad pump, I think, i have the replacement motor and strainer at home).
I left for 15 minutes and when i came home I tried to turn it on. Now the engine will crank and turn but will not start??? I still did not hear the fuel pump come on and pressurize the fuel. I am going to change out the pump motor later this week....

Do you have a security light illuminated on the instrument cluster? When the security module doesn't recognize the resistance in the key, it will disable the fuel pump to prevent the car from starting. In other words, the fuel pump not kicking on at prime may be a whole different issue unrelated to the low pressure readings you're getting. I do still believe the fuel pump and or fuel pressure regulator are bad due to the low pressure readings. The most common causes for the security light coming on are a dirty key or bad ignition cylinder. There are two thin wires that lead from the key cylinder that send the key resistance information to the security module.

Originally Posted by 3800Regal92

.....but Why did the starter not even turn before when i tried to crank the engine?? That is baffling me because if it is a stand alone fuel pump issue then the engine should always crank and just not turn on, right?.

You are correct that if just the fuel pump is bad, the engine should crank over, so you have other issues than just a possibly bad fuel pump. Some GM cars (the Camaro I know for sure) will disable both the starter crank circuit and the fuel pump if the security module can't recognize the key resistor, so these issues may be related. I cannot remember if the Regal is set up this way or not.

Originally Posted by 3800Regal92

Im going to wait another 30 minutes and try to crank it again, I'll listen for the pump first and see if it will turn on.

any help GREATLY APPRECIATED
Next update coming soon.....

Lastly, the suggestion above to try "high test" fuel is irrelevant. Your car only requires 87 octane so using higher octane will do nothing but cost you more to fill up.

[toddman67]

Start with the battery connections/starter connections. Although the starter may engage, you may not have power to the fuel pump or associated relays. If I'm not mistaken, you should see voltage to the fuel pump relay #30 all the time, 10-12 ga wire either orange or pink. The ignition will complete the circuit when turned on.
Fuel pressure should be no less than 37-42psi. Then check to see if the pressure rises with the regulator vacuum line either disconnected or pinched off and you should see 44-46psi. I noticed that you did'nt mention a new fuel filter? Replace the filter and don't skimp on the new fuel pump if that is your next move. GM, Delphi, stay away from airtex.
You also mentioned several new parts installed but did you remove the throttle body and do a good passage and bore/plate clean? Also clean the MAF and MAP sensors.
Your car will run good when cold being that the computer is in closed loop, Once things warm up the computer uses the sensors to make necessary adjustments during open loop. At anytime did you check for codes? go to www.troublecodes.net if you are not familar with obtaining flash codes.
Hope this helps.

[toddman67]

I failed to mention vacuum line in my last post. Check or replace them all. They may appear good but over time become porus causing leaks. These older cars used steel vacuum lines with hose connectors. check them all. Trans modulator, purge valve at canister and so on.

[3800Regal92]

changed the fuel pump(that was fun for the first time ever in the rain!). made a big mistake when purchasing the fuel pump bought an AIRTEX. lasted 25 min, then burnt out dead. finally found a delco parts dealer near me, thank god (anyone out there working om a GM, do yourself a favor, find a delco dealer<West Springfield auto parts>) got the delco pump put it in, still stalling upon heating up to temp. going to do the crank sensor now.

[3800Regal92]

no results after changing the fuel pump, still stalls. going for the crank sensor. hope it helps. anyone have ideas? i'm out of solutions after this one. please help

[3800Regal92]

need help on this one,i'm stumped.

[dwaynlakrz]

have u tried the mass air flow sensor?

[toddman67]

First of I would check for flash codes. Check www.troublcodes.net for information. Also many times these stalling issues can be solved by removing the throttle body, removing the sensors and cleaning it good with throttle body cleaner. Make sure the passages are clear. Vacuum lines are also a major cause of stalling. Check and clean EGR valve if applicable and the IAC valve seat and plunger.

[toddman67]

I moved my suggestion from your last post, so it's in the right area.
For the other folks out there you should be more specific on your troubles beginning with the year, make, engine and a brief explanation of the trouble and the components that you have replaced already.
The more information you can provide the more useful information you will receive.
Thanks.