j2b4o

Car has 126k on it and has no CEL or codes stored and the bulb is good.
The symptoms it produces is intermittent acceleration at low speeds and from a stop. Throttle position isn't a big factor in its behavior sometimes it comes back at WOT sometimes only when I feather te pedal. It isn't rapid it's atleast a second or 2 from power to no power.
It has only happened 3x. The first time it was very low on gas( barely above E). The next two times it happned right around the quarter tank mark( last time just above). All 3 times it was Hot as hell out and the car had been in slow moving bumper to bumper traffic for over an hour. Each time getting gas has solved the issue entirely. It doesn't happen every time I hit a quarter tank though.
My suspicions are that below a quarter tank the fuel pump is no longer submerged in gasoline and therefore not cooled. So under a constantly varying load in very hot weather it starts to overheat.
Has anyone ever had these symptoms under similar conditions? Anyone have a fuel pump burn out on a ufc10? If so what were the symptoms if any before it quit?

Thanks!

j2b4o

I forgot to include this in the first post.

The early symptom that this is going to happen is usually idle fluctuation at a stop. It's so quiet that I don't hear the idle drop by when it comes back it surges a bit (well under 800rpm) and i can feel it pull against the brakes. I think the ecu is trying to increase fuel pressure to compensate for the lack of flow so when the pump regains consciousness it comes back strong for a second or 2.

j2b4o

Reminds me of vapor lock on the old carburated jeep engines.

RA010623

iTrader: (1)

maybe check the fuel pump or fuel filter. sound like fuel delivery problem
when were those changed or inspected?

j2b4o

Yea I'm thinking fuel pump I finally found the thread I've been looking for. Several gen1 owners have had this exact problem and fixed it with a new pump. I'm fairly sure I changed the filter when I got the car if not I should have a new one in a box in the trunk because I know I bought one. Probably won't get to doing the pump untill next week sometime but I will report the results.

j2b4o

Was waiting till I was sure to update the thread.

Today I drive all over in mega traffic and severely oppressive heat. The gauge was right on a quarter tank when I left the house and is very close to E right now. The car has been running like a top the while time. More responsive and a noticable gain in Mpg.

The hardest part of replacing the pump was the small hose section that connects the in tank line to the one leaving the tank( the one exposed as soon a you open it up). It wasn't really a problem but a bit of a PIA even lubricated to get the hose fitted tl both lines, clamps and all.