Anyone ever replace the fuel pump?

[DannyBNH]

I have this intermittent problem of my fuel cutting out and I think I've exhausted every other possible issue. I bought a replacement fuel pump ( and filter ) hoping this will be the fix. I've heard from someone on Rennlist who had the exact same problem and the only fix was replacing the fuel pump.

So... How messy is this job?
Any tips?

[19psi]

If it's the same as my '82, it's about a 30 minute job you can do on the side of the road if you have the correct size wrenches and something to plug or crimp the fuel line out the bottom of the tank.
I was left stranded Sunday at a gas station after filling up my tank and had to be towed home so I'm in the process of changing mine right now. The only problem is no one keeps the pump in stock. I ordered a new Bosch from Advance Auto which should arrive today. It's $227 and you can apply a coupon code for $50 off which will drop it to $177 with free shipping.

It gets deeper though. My Bosch fuel pump was replaced at around 40K miles by the previous owner just before I bought the car. That was 3 years and 12K miles ago.
Right after filling the tank, I started the car and it died within 3 seconds. Pushed it to a parking space and did some trouble shooting...jumping the fuel pump relay resulted in a loud thunk sound from the rear. It was locked up solid.
After the flatbed tow home (no charge thanks to Hagerty insurance) I pulled the fuel pump. Hooked to an external power source, it would pull about 20 amps and not move. I dissected the pump and determined it was the impeller section that bound up and I was able to break it free by hand. After that it spun perfect and there was no damage or noticeable debris.

After that I drained some gas from the tank into a container and noticed what looked like two small paint chips in the bottom. I could pick them up in one solid piece but they would disappear if you rubbed them between your fingers. The pump tolerances are so close, something the thickness of a piece of paper can jam it solid (I experimented with it), so those easily dissolved flakes could be the culprit.

This is where it sucks because there is a fuel strainer/filter inside the tank that needs to come out. I had to drain 20+ gallons of gas (noticed more chips in the fuel).
After removing the fuel hose I used a 17mm socket to unscrew the strainer from the tank. Luckily it came out nicely...I feared removing the strainer because many times a knurled steel inset that is molded into the tank breaks free instead of the strainer. When that happens you either replace the tank or try to repair with an epoxy. Seems like there is at least one thread a month about this on the forums.

I was glad I removed it because those flakes were actually part of the strainer. If I had just installed a new pump, it would have been destroyed within a few miles.

This is the strainer which is mostly a frame now. Pieces were falling off just carrying it to the work bench.




This is the disassembled pump that it destroyed.

[RichardNew]

Most people, including Porsche shops, are using Fuel Injection Corp. They're great to deal with. The replacement pumps are junk. Especially the Bosch pumps. I think I paid $300 and it was a couple of weeks to turn it around.



It's almost like we've developed certain 911 rules at this point.

• Harvey for wheels
• Tony for interiors
• Fuel Injection Corp for fuel pumps

Richard Newton
Car Tech Stuff

[stepson]

Originally Posted by RichardNew

Most people, including Porsche shops, are using Fuel Injection Corp.

I've owned 7 928s since 2000 and I've never heard of Fuel Injection Corp. Any affiliation?

[19psi]

Never heard of them either.
Also this is the first I've heard of Bosch fuel pumps being junk. Pretty amazing as most cars come off the assembly line with them.

I Googled Fuel Injection Corp. and it appears they REMANUFACTURE fuel system parts. So do they take junk pumps (especially Bosch) and make them better?

[medipedicman]

I would suggest buying the pump and the S shaped hard line (that connects to the filter) at the same time.

I damaged the old line just trying to remove it. I got them both from 928 R US

[harborman]

What is the life span of the original fuel pump? In most cars they last many years.

[aluminum]

Use Line Wrenches not standard Wrenches : The job is simple except as some have mentioned Gas leaks from the disconnected line so crimp it off or drain the tank into some clean container .
Job Is Not messy with the right tools . Bosch Pumps are Just fine and high quality . I put a Used one on my 928 ( $75 ) and it still works fine now the years running by same pump .
I would be sure to check your Circuit panel is in good order first . Buy Brass Fuses if you don't have them ( the Aluminum tip Fuses Corrode and fail connection ) Clean the Panel Connections .
Fuel Pump Relay prongs must be clean with no Corrosion ( look for green color Corrosion ) Remove Relays very carefully or they well brake most often one must remove one to remove another pry from behind along edge
Now to remove and replace and clean the Tank , That's a Messy Tricky Job and requires a new Sender Gasket on top for sure or it shall leak. Something you might consider to clean out your tank . Pressure Wash at car wash or home .

[aluminum]

Use Line Wrenches not standard Wrenches : The job is simple except as some have mentioned Gas leaks from the disconnected line so crimp it off or drain the tank into some clean container .
Job Is Not messy with the right tools . Bosch Pumps are Just fine and high quality . I put a Used one on my 928 ( $75 ) and it still works fine now the years running by same pump .
I would be sure to check your Circuit panel is in good order first . Buy Brass Fuses if you don't have them ( the Aluminum tip Fuses Corrode and fail connection ) Clean the Panel Connections .
Fuel Pump Relay prongs must be clean with no Corrosion ( look for green color Corrosion ) Remove Relays very carefully or they well brake most often one must remove one to remove another pry from behind along edge
Now to remove and replace and clean the Tank , That's a Messy Tricky Job and requires a new Sender Gasket on top for sure or it shall leak. Something you might consider to clean out your tank . Pressure Wash at car wash or home .

[GabrielS]

I've a 84 928 s where the fuel stopped flowing. Checking the simple stuff first like connections and fuses, I found it was a defective fuel injection relay (about a $15 part). After applying some dielectric grease on the contacts then installing it, the engine started right up. I checked all my fuses and relays, cleaning all contacts and applying the grease to prevent corrosion and major headaches down the line.

[JK McDonald]

Hey Danny, Just a comment or two about fuel pump problems. I had a locked up fuel pump strand me one time in a mall parking lot. Our home wasn't too far away so I called my wife for some help and had her bring over my trouble shooting/emergency tool bag and some electrical stuff from the garage. I also asked her to bring a motorcycle battery that I luckily had on a trickle charger. After jumpering the fuel pump relay it was clear that the problem was definitely the pump. What the #$! it was only a year old. After dropping the rear cover plate and disconnecting the pump wires I used some short alligator clipped jumper wires to apply the motorcycle battery to the pump. Then repeatedly reversed the polarity of the battery until the pump started spinning. Use some caution and only touch the leads for a brief moment until the armature is free. Once the pump was running and I made it home, I drained the tank and replaced the tank's internal filter. I did later replace the pump but kept the old one for a spare.

Good Luck, Michael

[ROG100]

Most people, including Porsche shops, are using Fuel Injection Corp.

I buy all my rebuilt WUR and CIS distributors from them but CERTAINLY not fuel pumps.

Nothing wrong with Bosch pumps and I sell more than most people have had hot dinners 8>)

[Landseer]

For reliability its one of the key items to replace premptively during refresh/refurb of the vehicle.

Along with new strainer, tank-to-pump fuel line, fuel filter and sender gasket. Clean the fuel tank before installing it all.

Careful with the strainer removal, sometimes tank can be damaged.

[Danglerb]

$300 for a rebuilt pump seems a bit whack.

[tlister67]

I was able revive a Bosch fuel pump on my 928 project. It was varnished up from not running for many years. I pulled it off the car and used several doses of Berryman b12. Tried the polarity reversal and that might have helped. I might have to replace eventually but I can use while getting it running.

[harborman]

Make sure you disconnect the battery when doing the fuel pump! You don't want sparks around gas!

[lfausty]

the three washers in proper placement- wrenching the line down - get paper thin/got no crush left to them , wont tighten down enough without a leak, may not be right away few days they start backing off. * bring in hand to hardware store if don't have part number.