Car Dying While Driving--Fuel Filter?

[BASS]

Ok, I filled up my car, drove down to the races (about 70 miles), and the car was running fine. Car sat for most of the day, fired her up, and drove back home..After about 5 minutes of driving, the car started to stall out..It would stall out escpecially when Im coasting at the lights..So then, I would pull over and have a hard time starting it..Let it sit for a few minutes, and it would start then...then drive for 2 minutes, and it would cut out again...Did this cycle for about 1/2 hr, it felt like the car was not getting gas...Im thinking great, maybe its a bad crank sensor?

Im thinking maybe it was the MAF, so I disconnect it and drive the car, same thing (kept cutting out)...So, I pull into the gas station and figured Id get gas and see what happens..To my surprise, it took 10 gallons (even though I only drove the car about 70 miles)..Also, my digital gas gauge said I had 12 gallons still. Im thinking wow, this car got the crappiest gas mileage...So, on I go leaving the gas station, and the car ran fine! In the past, I would let the gauge go down to showing 2-4 gallons, and the car ran fine still..

Is it possibly a clogged gas filter? Im thinking maybe I got crappy gas from the 1st fill-up in the morning? The tank still had at least 6 gallons in the tank before I had to fill it up again, so the stalling problem was not because I had no gas in the tank... I replaced the gas filter about a year ago with a GM one, I guess it got clogged? Is this the typical symptoms of a bad/clogged filter? With a clogged filter, wouldnt the car not be able to idle at all? My car idled ok before I got the second gas fill-up..

 

[BASS]

UPDATE--I changed the gas filter, and drove the car around and it died on me again

Went to the gas station, filled it up with about 13 gallons, so, it looks like it dies out when I have about 5 gallons left in the tank (my digital gas gauge said about 6-7 gallons left, which is normal for the gauge to be off by 1-2 gallons)...

In the past, the car always ran with the gauge showing 2 gallons to Empty with no problems..

Im convinced it has something to do with the fuel pump (which I replaced about a year ago with the good Walbro one/new sock, etc..)..Is it possible that when there is about 5 gallons left, the pump isnt picking up the gas due to a back fuel sock or something??

I also noticed that when the car died out and if I let the car sit for about 5 minutes, it would start right back up and be able to drive for about a mile before it dies out again...

 

[Scott Atk]

When you did the pump did you change the hose that connects the pump to the sending unit assembly? Those are known for deteriorating. Once they develop a pinhole it will act similar.

 

[BASS]

Hmm, I cant remember if I changed that hose, but if it was in the kit that came with the pump, i most likely did..

If its not the hose thats the problem, im thinking it may be the Walbro pump itself.. Maybe its overheating when the gas level gets too low and just stops??

 

[Scott Atk]

When you drop the tank, check which p/n pump you have. If it's #169 they had a bad batch about the time you installed yours. Unfortunately you don't have any recourse as the time for returning them has lapsed. I would definitely replace it though.

 

[BASS]

Yeah, I knew there was a bad batch the other year but didnt know the #...Ill check when I take it out..Thanks!

 

[groumoutis]

This may be out there but do you have to crank it a while to get it to start? Longer than normal? If so the fuel pump relay could have failed and the oil pressure sender could be backing up the bad fuel pump relay and when you coast or idle the oil pressure drops and the oil pressure sender shuts down the fuel pump. I am not sure if it would shut it down but I know the oil pressure sender is a backup to the fuel pump relay in the even the fp relay fails. Turn your key on without starting the car and listen for the fuel pump to kick on!

 

[Razor]

Sounds like you have a bad fuel level sender. You make decisions based on what the gas guage tells you and these decisions have been bad ones.

If your filter was clogged.. it would do the stuff whether the tank was full or not.

So fill the tank up to the neck and drive around. If the problem goes away, then your problem is fuel pump/hangar/sock/etc inside the tank.

Those digital dash level gauges are not the best. Better not trust in it anymore. Better yet, reset your odometer everytime you fill up.

If your getting poor gas mileage, time to start looking as to why. Your scanmaster should give you a clue.

 

[BASS]

Groumoutis,

Yes, the fuel pump turns on as soon as I turn the key, so I dont believe its the relay..

Razor,

Yes, it def. has something to do with the fuel pump and/or sock since the problem went away when I filled it up...The problem occurs when there is about 5-6 gallons left in the tank..I was driving around for a while just wasting gas to lighten up the tank so I can drop it (maybe tomorrow) and see what the problem is...Im thinking its one of the faulty Walbro pumps that I installed the other year.. I have a feeling that the pump is overheating when the gas level is low because its no longer submerged in gas to cool it off..

One thing that I did notice, the car becomes extremely quiet when im coasting to come to a stop at the lights on the highway...Its as if the car is shut off and I can hear a pindrop inside the car, but it doesnt stall out and the car is normal (when the tank is full)..RPMs are at around 1200-1500 when im coasting down from 55 mph to the light...I guess this is normal, but its much quieter from what I can remember..

 

[Razor]

Me.. I'd have a brand new pump ready to install when the tank is dropped. That way I can address any possibilities.

Could also be the sock came off the pump as they are simply pressed on. This will allow it to aerate when the tank comes down fuel wise.

 

[robertmee]

I'd be interested in the solution as my 86 GN is behaving exactly the same way. Filled up, drove around for about 50 miles and then it died on me when coasting down a hill. Pulled into a parking lot and wouldn't restart for awhile. Removed the gas cap, reset the ECM, etc. and it finally restarted. Drove about a mile and it died again at the next light. Restarted after about 5 minutes and then drove it the rest of the way home two footed. As long as I kept the RPMs up I could keep it from dying although it would hesitate. I too have a Walbro, circa 2006 timeframe. Replaced the fuel filter, fixed some vacuum leaks, installed a fuel pressure gauge, and it ran fine on a full tank of the gas the next day.

 

[BASS]

Update--I dropped the tank and took out the pump, and everything appears normal (sock was still attached (clean), clean gas, and the fuel line attached to the pump outlet looked brand new)..I didnt see any pinhole leaks in this fuel line..

I also checked to make sure this wasnt one of the recalled Walbros from 2007.

Im guessing that the pump just crapped out and overheats when the gas level is too low..I ordered a new one already and ill be installing it soon and see what happens...

In the meantime, im sanding down the surface rust it has on the top of the tank and coating the whole tank with rust converter..:smile:

 

[BASS]

Ok, I swapped out the new pump on the sender, and I noticed that the center pipe (fuel return) that goes through the the plate of the sender assembly has a crack (looking at it from the bottom of the sender) all around the pipe directly where the pipe goes through this plate of the sender. It does not appear that the pipe itself is cracked, because when I wiggle the tube, it also wiggles the same way/direction on either end of the plate..It kind of looks like this is the tack weld that cracked thats located underneath the plate where this tube goes through the hole...I tried to see if the actual pipe iteself cracked by blowing through it and putting water through it, but it appears its ok...


Would this situation be OK? I also notice that the pump itself is mounted on this return pipe, and I am able to slightly wiggle this pipe due to this crack..

Here is a pic, but its kind of hard to see:

 

[BASS]

Update---It ended up being the fuel pump that was bad...I replaced it with a new Walbro today, and I ran the car all the way down to 2 gallons left in the tank and it still ran fine..

So I guess the old pump (Walbro, about 1.5 years old) crapped out and was overheating when it was no longer submersed in gas...:frown:

 

[pacecarta]

that wiggling tube is not good
the pump grounds to the hanger tube (return pipe) but the ground back to the battery is attached to the hanger cap out side the tank and completes the ground for the pump and the sender ,a loose or poor ground can cause fuel gauge to read higher ,
ive found those tubes wiggled loose from the pump weight and considering how hard our cars launch

the harness connection should have been attached to the return line above the tank
easy fix is attach a new ground lead outside the tank from the harness to the return tube using a hose clamp
looking at the underside you could attach a jumper ground from the return tube to the vent housing using small hose clamps and not have to worry about corrosion