92 Buick GS stalls with low fuel light comes on

[kenmolloy]

92 buick regal GS 3800 203,000 km.
stalls intermittantly..... most times will start right up, sometimes i have to wait a couple minutes before it will start. what i noticed is that the low feul light comes on even if tank is full befor it stalls out. has never stalled when low feul light is off.
what has been done.....
fuel tank was leaking so i replace with new tank & fuel pump....
fuel filter has been replaced.
crankshaft & camshft sensors have been replaced.... this has made it a bit better but still stalls just not as often.... speed does not seem to matter it will stall on highway doing 100 km/hr +, also will stall driving in town 50 km/hr and even at idle. with low fuel light on it does idle lower than when the light if off and idles a little rough with low fuel light on

Scan codes recieved.... 41 Cam sensor (recieved this before i replaced cam sensor and am still getting it after it was replaced....) had coded cleared scanner used was snap-on...

Service engine soon light on
ABS light on
seatbelt light on (does go out some times)

[richtazz]

Welcome to AF.
When you replaced the cam sensor, did they inspect/replace the magnet in the cam gear that the cam sensor gets it's signal from?

[kenmolloy]

thanks for your reply
No i did not, i could not see into hole, car has been running good today only stalled once this AM, and fuel light has been going off after 5 min (approx) from starting. if magnet was missing/damaged would the car not run good ever?

any advise on how to get to check magnet without taking front end apart?

[kenmolloy]

well, got in to checking the magnet behind the cam sensor today. and there is a magnet there took it out and cleaned it up and replaceced it and still no difference. on thing though it stalled today when the low fuel light was off. also noticed that the speedodometer pegs to the right when it stalls.... never noticed this before, the tach does move a bit when its starting to die but does not move much. the magnet on the cam is very small not sure how big it is supposed to be but the magnet is only abouot 1/3 size of the slot it is sitting in. called jobbers today to see if i could get a new magnet but they do not list one, wondering if I need to buy the cam to get a new one? hope not. magnet seems to be ok, it was very dirty, cleaned it up but car is still stalling....???? anyone have any ideas????

[richtazz]

the magnet is very small, and has a little plastic retainer "cage" that holds it in the cam gear. The magnet part number is AC-Delco 25530386. It runs about $16 at a Delco retailer, or about $22 at the dealer. It doesn't sound like this is your issue though with the other electrical gremlins you're having. I would inspect the ECM for water intrusion damage since it's mounted under the hood and exposed to the elements. It's under a cover in the passenger side fenderwell between the wheel well and passenger side headlamp.

[kenmolloy]

Thanks rich, i apprieciate all the time your spending on this to help me.

this is good to know, when i first saw magnet it was so full of crud in the cage the magnet looked like it was the same size as the cage, then when i pulled out it seemed that the magnet was starting to disintergrate down to the size of a Tic Tac..

Was also talking to an old friend from Vancouver (He runs his own auto shop there) he told me i should replace the pig tails on both sensors, he was saying that this is a common problem with these buicks, so he just replaces the pig tails whenever he replaces the sensors, he admits that it is not always neccessary but it reduces clients returning to his shop.

So when i was checking out the magnet I had a good (best i could) look at wiring and when i felt for the harness the loom was disintergrating in my hands, and i found a few wire repairs to both harnesses.
I tried to source out new pig tails and only GM has them and they want $150 bucks for the pair.

So my plan this weekend is to take off power steering pump, alternator, & water pump pulley, and check out the wiring and pig tails before throwing $150 on a maybe, also good time to replace wiring loom as well.

Also i will take a good look at the ECM like your suggesting, any advise at what i should be looking for.... i had a quick look at the ECM when i replaced the Crank Sensor and did not see any obvious damage there.... should i pull it right out? any test i can perform with a multi meter? I have a decient one (Fluke).

Thanks in advance
-Ken

[kenmolloy]

Removed the ECM and it looks fine, it is encased in Plastic, no signs of any water damage, removed wiring and pins look new.

removed the wiring harness for the cam and crank sensors to the ICM, the wiring repairs i saw early were factory maded for where the wires from can and crank join, check for continuity of all the wires and could not find any opens in the wire (.01 Ohms resistance in all wires) re-loomed the harness, put it all back together and the SES light came back on as soon as i put it in gear

Was working at a friends bout 20 mi away so decieded to head home, this time it kept stalling really bad, and would not restart for several minutes between, i noticed that the fuel pump was not turning on after it stalled, but as soon as it came on the car would start and drive about 2-3 min, stopped by another friend on way home (he has a scanner) scanned and..... code 41 Again, told him i was sure it was fuel now and not electrical, cause now when it dies it dies like it running out of fuel, not like before it would just die no sputter just like i turned the key off. so i borrowed his fuel gauge and.... when i turned on it would pressurize to 40 psi but very slowly (maybe this has something to do with the low fuel light being on), started car and pressure would drop to 20, then rise to 40 and then back again, when it died the pressure dropped alll the way to "0"....

Sooo... I removed the fuel relay and jummpered it... bang right up to 40 psi and held it there.... drove to gas station and put $20 in (wanted to keep tank above 1/2 with the relay jumpered (btw low feul light is staying on), went for a nice long drive both city and highway and no more stalling,but now car idles low (500-600 rpm) before when car was running good it would idle at 900-1000 rpm. and it sounds rough at idle and sometimes stumbles a bit at take off.

not sure where to go from here I am thinking ICM? priced one out and.... $450 , hoping they though i was asking for a ECM.., someone suggested it may be the TPS.... anyone have any ideas/tests i can do to isolate further....

On the brighter side now i can at least drive more than 5k at a time...lol

[kenmolloy]

well been 3 days of driving with the fuel pump relay jumpered and the car has not stalled, still idleing at 500-600 (does not stay constant) not sure what the idle is supposed to be at?

other than that car is running great since i cleaned up enging grounds and reloomed the crank/cam/ICM harness.

one point i forgot to mention in previous reply was that the wires were exposed at the ICM pigtail, and i repaired them by taping each one and then holding with slight pressure i filled the spaces between all wires at the ICM pigtail with high resistance RTV, i feel this has improved my problem as before when it stalled sometimes it felt like electrical and sometimes it felt like gas. Now when it stalled (before jumpering relay) it always felt like lack of gas, and would never start right back up

low fuel light keeps coming on but does go off more often than before.
seat belt light workes properly.
SES light staying on.
anti-lock light is still staying on, I am pretty sure ABS is working as i have done several panic stops (from 60 MPH) and cannot get brakes to lock up, and vehicle stops quickly.

Not sure where to go from here and was hoping someone would have some suggestions for me to try as i try to isolate the problem so i can fix car properly...... (jumpering relay before starting and removing when i park is annoying, although a great anti-theft exercise...lol).

Thanks in advance
-Ken

[kenmolloy]

well it looks like nobody has any further sugestions fo me to try, thx anyway guys

[3100]

Hi, loss of cam signal will not stall your engine, you have other problems. Your engine is sfi sequential fuel injection and when it looses signal it will go into MFI mode. It will still run and will be able to restart with increased fuel consumption. Give me all your codes (please just give me numbers don't interpret codes).

[kenmolloy]

Hi 3100
only code i get is 41....(code i got before doing anything and still same code i am get today)

to recap for you i have replaced gas tank (was leaking bad) and replaced fuel pump assembly while i had tank out.

cam sensor, and crank sensor have been replaced.

removed the wiring harness for cam crank and ICM) wires tested and no opens found... did repair harnes at the ICM pigtail, plastic coating was breaking off due to heat. heald pig tail in vise applied slight tension to wires so the kept separated and filled in with high heat resistant RTV to keep wires from shorting against easch other, allowed RTV to dry then reloomed and put back in.

removed PCM and inspected case and plugs for any signs of water damage or corression. there was no signs of any damage to case, plugs, or pins.

at this point car still stalled, and codes were cleared via a scanner and car through a code 41 again.

Jumpered the fuel relay and now car has not stalled since(June 27), does have a slight miss at idle (this is itermediate, and i believe it is due to small crack in vacuum line at the electronic EGR, will be getting some vacuum lines this payday and will start inspecting all lines and replacing as nessary)

Any ideas and suggestions will be greatly apprieciated.
Thanks in advance
-Ken

[3100]

Hey, Kenmolloy I need to know when you turn the key into run position do all the lights for the gauges come ON? Does the light for oil pressure come on? Does the fuel low level come on and remain on for 3 seconds?

[kenmolloy]

3100:
low fuel indicator does not come on
Oil Pressure does not come on

Coolant lvl comes on for 1/2 sec then goes out
Check gauges light comes on
SES comes on
Anti-Break comes on

-Ken

[3100]

please try this: Put the f/p relay back in and disconnect oil pressure switch. Test drive the car and tell me what happens.


oil pressure switch you will find above crankshaft balancer and it has 4 wires (black, tan, gray and maybe orange (not sure about the color of the 4th wire))

[kenmolloy]

hi 3100,
not sure what colors the wires were but there was only one sensor where you're describing other than the cam shaft higher up and towards waterpump.

pulled plug and replaced f/p relay, and when i put key into run position. oil pressure gauge went all the way to the top and car would not start.
pulled f/p relay and jumpered and car still not start.

replaced plug and oil gauge went back to normal.
but now when i turn car off the volt meter goes down as far as it can. with key in run position the volt meter goes to zero. all gauges are workin when car running.

car stalled a few times on me today after i performed this test, but started right back up.