Fuel pump '88 XJ-S H&E issue

XJ-S
1

Hi, I know this has been covered before, but I can’t find a thread for my particularly irritating problem. The car stalled in the middle of the road, and I was able to coast to safety. Fuel gauge is fussy, so added gas. Wouldn’t start (but turns over great). Put new fuel filter in, ran like a champ, no flutter in RPMs, lots of power, problem solved, right? Wrong. A few days later, it starts up, then dies. Now when it turns over, it just sounds like it doesn’t “catch” to run. What’s up with this?

  1. Fuse
  2. Relay
  3. Pump
  4. Filter (again?)

I know where to start, but the finish could be long and hard.
Thanks!
BubblesSister

2
  1. Engine temp sensor.
1 Like
3

Thanks, will add to list.

4

One consideration that is worthy of thought. Initially sludge was picked up blocking your filter …you replaced filter… ran well until new filter blocked by the same supply of sludge.
The fix would be to drain and flush your tank.

5

Kirby also mentions many times about sock filter in surge tank clogging.

6

While that sock can clog because of crap in the tanks, filtering is not it’s only function. It is primarily there to ensure that no air enters the fuel lines during cornering, low fuel conditions, etc. The gasoline forms surface tension on the mesh, and as long as it’s maintained, it will keep air out of the system, even if the whole mesh is not submerged. Look at any recent fuel tank pickup, and you will see a similar design. Removing it and replacing it with an external filter, while somewhat simplifying changing filtration, does not maintain the primary function of the sock. You can argue that the surge tank in many versions of the XJS make the sock somewhat redundant. But it is not that hard to change, and you can instantly see if it’s clogged when removed, unlike most easily available external filters.

The best thing to do is flush the tanks, and use ethanol free gasoline to keep moisture, varnish, and rust out of the system.

1 Like
7

Thanks, Greg, I’ll add that to the list. The fuel pump is energizing when I flip the key to psn 2, so it’s thankfully not the pump.

8

Thanks, jal5678, the problem started within a few miles of adding octane booster to 91 ethanol-free fuel, along with some Seafoam into a full tank of gas. I’ve typically altered the additives, but I got lazy and fed them both in on the same tank of fuel. And so my problems began. Today I’ll take out the new fuel filter and check the condition of it. If it’s clogged, I’ll read the book to do a fuel system flush. Anyone know off-hand the size of the lower tank?

9

…never mind. Top tank 14 gallons, bottom 11. “This one goes to 11…” from Spinal Tap. Many thanks to Kirby, it was in The Book.

10

phnellie aka Trev, OF COURSE I have a full tank of gas. Just OF COURSE.