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Last week, my 1988 F150 with two in tank pumps, one on the rail and a fuel tank selector valve, stopped running properly on the front tank.
Also, the rear tank is filling the front tank.
Yesterday, I put a fuel tank selector valve on, and drove a 15 mile loop on the front tank, and a 15 mile loop on the rear tank. I also drove it about 25 more miles, just on the front tank. As of yesterday, everything seemed good, but I did notice the front tank fuel gauge wasn't dropping.
This morning I took off on about a 20 mile round trip. About 5 miles in, running on the front pump, the truck started acting the same as last week. The truck stumbles and almost stalls, until I switch to the rear tank, then it runs fine, but continues to fill the front tank.
I'm thinking I need a new front tank pump but why would the rear continue filling the front?
Yep. Front pump needs replacement. I don't fully understand why, but each pump has some kind of back flow device that seems to go out as the pump fails. This allows the return line to fill the non selected tank. I have had the same issue with my 94.
Yep. Front pump needs replacement. I don't fully understand why, but each pump has some kind of back flow device that seems to go out as the pump fails. This allows the return line to fill the non selected tank. I have had the same issue with my 94.
I'm thinking front pump too, but the '88 pumps were different than the '94's. I'm not sure if the '88 pumps had a check valve, or if that was done in the fuel tank selector valve.
I bought it new through Amazon. It wasn't the cheapest one, and it came with "official" looking installation instructions.
About 2 out of 10 reviews were bad.
In 2018, at the beginning of this project, I put new tanks, new in tank pumps and a new fuel tank selector valve on.
There were times periods where the truck sat unused, but I usually started it at least every few weeks.
Was in Ford packaging? Did it have the engineering number on it somewhere?
It has a sticker on it. I'm getting ready to look at it right now.
I'm going to take the DFR I removed yesterday apart. Maybe I'll see something obviously wrong with it.
If that's the case, and I can fix it (I know that's a stretch), I could put it back on the truck.
This is the DFR I took off the truck yesterday. I cleaned it up and lubed it with motor oil and put it back on the truck.
Sitting here now with the truck idling. It has stalled once on the front tank and wouldn't restart until I switched to the back tank.
It's idling on the front tank at the moment.
Your fuel will not pump into another tank without going through the revisor first. Looking at your last picture, your front tank is very dirty, which has contaminated the original revisor. Clean it up good, drop your front tank and clean it, then put in a new fuel pump, since the old one obliviously has lost the filter screen, or has a deteriorated filter screen on it.
I guess that explains it. I just ran a 12 mile round trip, half on one tank, half on the other. Is there any chance that rust is from the top metal washer in the DFR, from times that the truck sat?
There's no doubt there's a lot of debris in the fuel lines but it must be either from prior to 2018, which is when I put new tanks, pumps and a DFR in, or it's rust that formed between 2018 and now.
There were times it sat and I didn't get to start it very often.
The DFR that I posted the picture of, was stuck in the "down" position. I pulled the center piston out and loosened everything up best I could.
I appreciate the help and advice.
Here's a picture of the sticker that's on both DFRs.
Your fuel will not pump into another tank without going through the revisor first. Looking at your last picture, your front tank is very dirty, which has contaminated the original revisor. Clean it up good, drop your front tank and clean it, then put in a new fuel pump, since the old one obliviously has lost the filter screen, or has a deteriorated filter screen on it.
What's the best way to clean that front tank out once I get it down out of there?
