Hi guys. Please allow me to add a few comments of value. A real lot of people have had trouble with repeat failing fuel pumps on Chrysler products, but it is not the pumps' fault. As the typical story goes, the running or failure to start problem is solved with a new fuel pump, but it fails again, usually within a few weeks. Second, third, and fourth pumps do the same thing. Finally, out of frustration, you buy one from the dealer and have no more problems.
The dealer's pump was not the solution. The cause was determined to be microscopic debris in the tank that plugged the impellers causing the pump motors to run slow or not start up at all. If it does get up to speed, it will rarely stall during that drive cycle. I'm suspicious that debris is caused by mold that feeds on the alcohol in today's gas.
With each new pump, a little more of that debris gets collected in the impeller, until after multiple replacements, most of that is gone. Be aware too, a fuel pump is not something a company is going to go through all the research and development, and then produce the lowest quality, (cost) version possible. They usually try to improve on an original equipment design. Many of the aftermarket pumps you can find, (Napa's in particular) come from the same supplier that built them for Chrysler. They just rebox them with their own name on them.
The other consideration is how the pump is replaced. If you buy a complete housing with the new pump and motor inside, it comes with a new fuel level sending unit and a new strainer. Those strainers cause a lot more trouble than the fuel filter. In fact, on older models where the filter is along the right frame rail, the fuel filter typically lasts the life of the vehicle, unless it rusts out and starts leaking. It is very unlikely you'll solve a running problem by replacing the fuel filter on those older Chrysler models. I don't know the history of the newer style with the filter in the tank.
Often people like me look for the least expensive route which is to replace the pump itself and reuse the housing, sending unit and strainer. This is more work but lower cost. Either way it's not addressing the actual cause of the problem. If the old strainer is collapsing from being plugged and the pump is pulling a vacuum on it, the symptoms will return right away. If it's the impeller that's becoming plugged, it takes a few weeks for the symptoms to return.
The solution for repeat fuel pump failures is to have the tank steam cleaned at a radiator repair shop, then install the new pump. As for that strainer, or pick-up screen / sock, mine became plugged twice over 440,000 miles on my '88 Grand Caravan, causing a very intermittent and elusive stalling problem. A new sock cost $12.00 and just snapped onto the bottom of the fuel pump's housing. On my '94 model, that sock was not available or replaceable separately, but I never ran into a plugged one either.
One major clue to a plugged or collapsing sock is the engine runs worst when the highest volume of fuel is being pumped, which is during coasting. Under load or when at highway speed, there won't be any symptoms and the engine runs fine.
I had plugged strainers on two older carbureted cars years ago, but those ran okay at idle when enough fuel could sneak through. Both ran okay at highway speed for the first 15 miles, then, after sitting on the side of the road in a pile of tears, they would start and run again for another two or three miles before I had to give up and coast to the side of the road again. The theory was they needed a couple of minutes to relax and expand to their original shape so fuel could get through again. Those just slid onto the pickup tube at the bottom of the tank, and cost $3.00 each from the dealer's parts department.
As a point of interest, this same problem occurred on a mid '70s GM car. My instructor did a demonstration where he removed the gas cap, then pulled the fuel supply line off the mechanical fuel pump on the engine. He used a rubber-tipped air nozzle to give it a shot of compressed air into that pipe, and blew the strainer off the pickup pipe. It solved the fuel starvation problem. There was still GM's sintered metal filter in the carburetor to collect debris that got through. Don't know how or if the owner addressed the strainer after that.
Mechanical fuel pumps are of a different design, and they won't be affected by that debris in the system. According to an instructor from Napa, Chrysler's electric fuel pumps are built to very tight clearances to make them quiet, but that is what makes them more susceptible to plugging up and binding. Other than that, when their pumps do fail, it is almost always due to worn brushes and a failure to start up. That leaves you sitting in the driveway or parking lot. (Often banging on the gas tank gets them going). GM's fuel pumps rarely fail to start up. They seem to fail more due to worn bearings. They stop running while driving, leaving you sitting on the side of the road. Most of the time they will work again for a little while if they're allowed to sit for a little while.
MARWEE, you didn't say what you found for fuel pressure. The second time this happened to my van, I drove for a year and a half with the fuel pressure gauge tied to the radio antenna so I could watch it. The symptoms finally acted up with regularity when I was dragging a tandem-axle enclosed trailer home from an old car show swap meet. That trailer is bigger and heavier than the van. Normal fuel pressure is around 45 - 50 psi. With the really heavy load, the pressure would slowly drop to 20 psi. A lot of engines, especially GM truck engines, show symptoms when fuel pressure drops just five pounds. Mine didn't start to sputter and lose power until pressure dropped to 15 psi, which really surprised me. What I found is if I lifted the accelerator pedal for just an instant, pressure would pop back up to 50 psi, then resume its gradual drop over about 20 seconds. I nursed it 55 miles to home that way. Next few weeks, with no trailer, there were no symptoms again.
I had to stick my nose in here because I've had this problem multiple times. Hope this gives you guys some more ideas.
Tuesday, February 7th, 2023 AT 4:47 PM
