Fuel system woes on an 86 2.9

[mclumber1]

I have an 86 ranger 2.9 4x4 that has been in our family since 1989. When my dad drove it, it ate up several low and high pressure pumps. After a year of scratching heads why this was happening, a local ford expert indicated in might be the inertia switch. After looking into it further, the switch was bad, and was only sending out 10-11 volts to the two pumps, which what was causing them to fry themselves.

I've now had the truck for the last few years, and for the most part, has been pretty trouble free. However, I've recently started experiencing what I can only assume are fuel pump/system issues. Once the truck is warmed up, the pump (And I'm thinking it's the HP pump) becomes very noisy. Eventually, the pump begins to cut in and out and then stop, which kills the engine within a few seconds due to no fuel pressure.

I've checked voltage at both the fuel pump relay and inertia switch and have a good 13.x volts while the car is running. I changed out the low pressure filter (that o-ring is frustrating), and the problem persists. I've also exercised the fuel pressure regulator with a vacuum pump and the regulator seems to be able to be moving freely.

I have not yet checked the HP pump itself or the filter, but according to my dad, both are only about 3 years old. Running codes only gives me issues with the EGR system and the "heated exhaust" (which I'm assuming is o2 sensor).

What else can I check to see why I'm having these issues?

Alternatively, how difficult would it be to install a single, high pressure pump from a 90 or newer 2.9 system?

 

[IIBRONCOS]

It seems you need a new HP fuel pump. That o ring on the accumulator stays in place better with a light coating of grease, but is still touchy to install.

 

[alwaysFlOoReD]

I can't speak to personally installing a HP pump into an early tank. However I did own a B-2 that the previous owner had put a 4.0 into. He told me he sourced a HP pump from a mustang. When I looked he had cut/filed the tank opening so the tangs in the pump would fit. So it definitely is possible. Perhaps someone else has personal experience?

 

[RonD]

Ford reversed the Gas gauge OHMS in 1989 and up, so you would lose the gas gauge if you swapped the whole fuel pump assembly in the tank.

3rd party fuel pumps may only last a short time, not unusual.

You said you can hear a noise after warm up, have you confirmed it is the pump in the frame rail and not the lift pump in the gas tank?

If so I would replace the pump again
Motorcraft(stock) pumps run $500+, 3rd party $70-$100 so most DO USE 3rd party pumps

 

[mclumber1]

Ford reversed the Gas gauge OHMS in 1989 and up, so you would lose the gas gauge if you swapped the whole fuel pump assembly in the tank.

3rd party fuel pumps may only last a short time, not unusual.

You said you can hear a noise after warm up, have you confirmed it is the pump in the frame rail and not the lift pump in the gas tank?

If so I would replace the pump again
Motorcraft(stock) pumps run $500+, 3rd party $70-$100 so most DO USE 3rd party pumps

I wouldn't be too heartbroken if I lost my fuel gage, as it goes from F to E after about 40 miles into a full tank. I use my trip odometer to know when to fill up with gas.

Do I know for a fact that it's the HP pump? No. However, putting my ear near the pump vs the tank, it seems to be louder at the HP pump. If I don't do a single pump conversion, it probably would be worth it to change out both pumps. I was concerned about having to drop the tank and doing either method, but I just realized (after watching some youtube videos, it's easier to tilt the bed up (or remove it) to get to the top of the gas tank.

 

[RonD]

Yes, removing the 6 bolts that hold the bed on and the 3 screws for filler hose is easier way to get at the top of the gas tank

Dropping the gas tank is not the hard part, getting it back in with wires and hoses intact and lined up is the hard part

The bed bolts can be rusted pretty good/bad, but you can hit wrecking yards to get replacement bed bolts and nuts, front two are longer than rear 4 bolts

If you are going to slide the bed back don't for get to unhook the tail lights



If you decide to go with the newer(1989 and up) high pressure in tank pump and sender it is 16(empty)-158ohms(full), there are 3rd party gauges that are 15-160ohm which will work

 

[mclumber1]

I can't speak to personally installing a HP pump into an early tank. However I did own a B-2 that the previous owner had put a 4.0 into. He told me he sourced a HP pump from a mustang. When I looked he had cut/filed the tank opening so the tangs in the pump would fit. So it definitely is possible. Perhaps someone else has personal experience?

That's good to know. I've heard that people have in fact done this retrofit with a 90+ Ranger pump, but I'd want to verify that it's a direct fit in the tank without any modifications to the tank or pump.