background: 4 months ago on vacation, the fuel filter on my 96 4.0L clogged up. Had a shop put a new filter in, and it ran fine after that. I did have the mechanic check the pump, and it tested out at 32PSI, slightly below the factory recommended minimum of 35psi.

Fast forward to yesterday: The van died out on me again (started missing and acting sluggish, then the engine died.) Pulled into a lot and waited a minute and it would start, sputter and die. Waited 5 minutes, and it started back up and I was able to drive it the rest of the way home (1/2 mile or so).

These symptoms are exactly the same as when the filter went out before! There have been no other performance issues since I put the new filter in (no misses, lugging, etc.)

Questions: I will be putting a new filter on tonight. What the heck could cause this one to foul up after 4 months and about 2,000 miles? Anything I should do about that?

Do these fuel pumps die a slow death - should I have this one tested again?? My past experiences with fuel pumps has always been a catastrophic failure - it either worked or it didn't. What is the likelihood that the fuel pump itself is causing problems?

Thanks in advance, I'll post some more after I change things out.

 

That is rather odd. Since the fuel tank is plastic, a rust fouled filter could be eliminated. If the new filter solves the problem, cutting open the old one to verify the type of contaminant would be a first step.

Unless there is some bizarre reaction occuring in your tank to clog a new filter, I would tend to think there are other explanations. In general terms, I tend to agree with your view that fuel pumps either work or fail catastrophicly. However, any electric motor can wear down to a point of intermittent failures. Starters are a good example.

Another remote possibility is the tank is failing to vent properly during operation, allowing a vacuum buildup that reduces the pump output. Waiting the several minutes before restart may allow the pressure differential to equalize. You could wait until this happens again and quickly open the gas cap to see if the tank is carrying a heavy vacuum. Now, having said that, I can theorize how it could happen but I don't know how in reality it would occur, since the tank is vented at the gas cap, the fuel pressure regulator return line and the vapor cannister line. All three would have to fail to cause this - fairly unlikely.

Odds on favorite at this point would be the fuel pump. Interesting problem, keep us posted as to what you find.

 

Thanks for the reply. I will check the filter when I pull it out.

The only other thing I can think of is that somehow, some contamination got into the tank and is now getting stirred up and pump out of the tank. (I bought this thing used, so I don't really know it's history).

 

Ford has problems with fuel pumps in some years of Focuses. They start wearing inside and the junk from that goes through the pump and can plug the fuel filter. I wonder if this is the same sort of problem.
Like aerocolorado said the fuel pump is the likely suspect. Sometimes they die when they heat up and run again after cooling down for a few minutes.

 

Sounds like my issue. Seems to work fine around town. Both times it died was after a few miles on the freeway in hot conditions.

Pulled the filter last night and installed a new one. The old one had some moderate blockage (based solely on my ability to blow through it). I'll monitor it going forward.

I'd rather not have to drop the tank and replace the pump, but I'll add that to the list of things to do.

Thanks for the help, guys!