1993 Ford Ranger V6 4.0 bucking and stumbling on acceleration

[cookiejar]

OK sounds good, I will try that tomorrow.

 

[cookiejar]

I warmed up the truck today until the problem started again, I pulled it over when the truck would go no further and I pulled the 30 amp fuse for the fuel pump relay. The idle slowed way down but it did not stall so I gave it a little throttle and then it stalled out. I put the fuse back in and started it up again without turning it off and I had full pedal with good acceleration again. Tried it twice and got the same result so most likely the fuel pump or in tank filter but not the computer?

 

[RonD]

If you pulled the fuel pump fuse it should stall instantly even at idle?

You sure it was fuel pump fuse?

According to this diagram it should be a 20amp fuse
30 amp is the computer fuse

 

[cookiejar]

Oh sorry the truck is a 1991 and the engine compartment fuse box is labeled 30 amp Fuel Pump Relay I think

 

[RonD]

OK,

In 1991 Fuse #1 should be fuel pump power
Fuse #8 is computer
both 30amp

The FP relay doesn't have its own fuse, however it is powered by fuse #8, the EEC(computer) fuse

So fuse #1 is the one you want to pull, so computer stays running but pump shuts off

But I would think pulling #8 would shut down engine instantly, no injectors, so maybe you did pull #1

 

[cookiejar]

I am including a picture of the fuse box under the hood on the passenger side. I pulled the one labeled Fuel Relay and one time it stalled right away and one time it continued to turn over very slowly until I reved the throttle Then it stalled. The fuse box does not have numbers for the fuses but there is one called Engine Comp LP 15 amp.

 

[RonD]

Thats the right fuse, the FP Relay, odd it is labelled like that

 

[cookiejar]

I pulled the correct fuse to shut down the fuel pump and the issue goes away for a few miles. I only had the fuel pump shut down for about a minute. Is the most likely issue the in tank fuel pump or the filter?

 

[RonD]

Well filter is cheap, change that first

 

[cookiejar]

The truck is fixed!!!! Thank you RonD, you were spot on, the fuel pump strainer filter was all plugged up and the bottom screen on the pump itself was clogged. Runs like new! Squeals the tires and 85 before I am off of the on ramp! And easy to replace, I thought I would have to drop the tank but just 6 bolts slide the truck bed back about 8 inches and pull the fuel pump out.

 

[RonD]

Good work

Thanks for posting the FIX that worked, it will help someone else down the road