TAREK

My 86.5 AT drove 172,000 mi with no fuel issues...EVER!!! I had to let it sit for about 10 months (since last SITM) starting it occasionally, until 3 weeks ago when it wouldn't start. Concluded a failing fuel pump, which I replaced, and voila! it started right up. Following another week of sitting, it wouldn't start, and it was the fuel pump again!!!! Replaced it and voila again! It's a week later (also not driven) and no start again!!! Sure enough, fuel pump #3 is dead!!!!

Has anyone had this happen to them before? Is it possible that a tiny wiring problem somewhere keeps feeding current to the pump while sitting and kills it eventually?

I had to pull pumps from other cars, so now I'm down 3 pumps. anyone wants to sell me 3 fuel pumps for a reasonable price?

jpitman2

Are the 'dead' pumps electrically damaged? ie, is there a short to the body from either connection, or open circuit or short across the connectors? If there is open circuit I suggest you look for a high resistance somewhere in the wiring (relay or fuse?) that is lifting the amps and frying something. The fuse should blow before this happens, so check the fuse for correct rating.
Does the pump conduct? I would guess they have ingested some rubbish and are jammed internally. My normal pump draws ~6A running delivering fuel. If one of yours (in liquid) draws nothing then its open circuit internally. Try applying reverse polarity briefly (not good to run dry) and see if it will spin at all. If it jerks as you apply 12V its trying to turn. Mine died in traffic on me once, and when I put +12V across it (out of car), it spat out some small object, and hasnt stopped since.
jp 83 Euro S AT 49k

Rehan

If you have an in tank fuel pump, change that one and clean the gas tank. If the in-tank fuel pump is broken it will let debris pass in to the high pressure fuel pump.

TAREK

Yes pump #1 and #2 were trying to turn and would "jerk" instead....but were electrically dead when tested out of the car. Could be because they jerked too many times as I tested?! I haven't touched this last one, so I'll be more methodical this time. I work fairly long hours, but I may get to it late tonight. I would be surprised if it turns out to be debris in the tank, because fuel was flowing strongly (by gravity) as I disconnected lines for pump replacement.
Thanks!

TAREK

If all electrical issues are a pass, I will make sure to do that. Thanks for the suggestion. How does one test the in-tank pump independently?
Thanks

Rehan

You have to remove it to see if it's broken or not. There's a rubber hose that is part of the pump, that just breaks. You need to empty the tank to get to it.

Rich9928p

Rehan is correct, you need to check your in-tank filter [item number 2], or, if you have a 2nd fuel pump (in-tank) check that along with the intake filter [item number 1]. Often, this in-tank filter gets clogged or breaks and the fuel pump doesn't run properly or inhales large particles that causes the pump to freeze.

This diagram shows the details. You will need to replace the Sealing Ring [item 3], P/N 928 201 187 02.

heinrich

I'm thinking sitting that long (not too ling actually, 10 mos) ... maybe there's crystallised fuel / debris in your tank. Check that while you're in there.

UKKid35

If two out of three are now seized that would definitely suggest debris. You might decide to open up one of them to see, you have nothing to lose.

TAREK

I guess it's time to remove the tank and look at everything in there. With the car being outside and me having time only at night, it's starting to look like a weekend job!

Rixster gave me a decent deal on 2 pumps. Thanks Rixter !

Rehan

Tarek, there's no need to remove the tank. Just lower the rear tank straps and that will give you enough space to access to the in-tank pump. Don't forget to empty the tank before doing this.

TAREK

Will do. Thanks. I guess it's a good thing the car is parked on a slanted driveway, facing up!

Tarek

Scott M.

Tarek;

You don't have an in tank pump. I didn't see one while under there.

The 2nd pumps life was suspect. A relay jumper was left in place most likely contributing to its' demise.

I did mention to you of the few burned wires I saw under the fuse panel. Start there. Also, look at the FP relay and make sure it isn't faulty (stuck on).

I'll call you in a few minutes after I get those measurements you need.

Scott

Garth S

The in-tank pumps generally appeared late '88 on - but you have the strainer Rich demonstrated.
There can be some risk of spinning the fitting out of the tank if done less than perfectly: another side step is to lift the hatch rug and round cover behind the passenger seat. If you can loosen the ~4" gland nut, the level sender gear lifts out. With a flashlight securely anchored to your neck, you should be able to see a crystal clear pool of gas - and the strainer.

partstat

check that gas tank is venting. I had a creased vent line in front pass. fender that made me eat 2 pumps a while back. Next time car is running open gas cap and make sure it is not getting pressurized.