Hello everybody. I could use alittle help diagnosing my fathers 88 bronco. Here's some history. It was on propane and sat for about 10 years. I've switched it back to gas, installed a new tank, in tank pump, rebuilt injectors and fuel filter. It ran fine for the first couple test drives then started to loose power after longer drives. It would hardly rev over 3500 rpm. So I put my fuel gauge on it and found it loosing pressure (like down to 10 psi when trying to rev it up) so I was thinking maybe some crap from the lines plugged the new filter. Changed it out and it still is the same way. Hardly any power after it runs for more then 20mins. The fuel pressure is just a tick over 30psi at idle and climbs up to 38ish with the regulator unplugged. It also holds good when I shut the truck off. So I'm thinking high pressure fuel pump maybe? What do you guys think? Thanks in advance.

 

Here's a diagram to help you out. Compliments of Subford:

 

I had a 88 bronco with a 5.8l and it had a pump in the tank along with a high pressure pump on the frame rail. Didn't realize it had two pumps until I had the high pressure one on the rail start acting up. It would get hot then quit, after replacing it twice, I finally realized it had one in the tank. Replaced it and I didn't have anymore problems.

 

Thanks for the feedback. Ya I replaced the one in the tank already.

 

I replaced the high pressure pump today. Same thing. Runs out of fuel around 3500rpm. So other than the fuel pressure regulator (which we ordered) and the lines it will all be new. Anybody have any ideas. I sure would appreciate some help here.

 

Is it possible for something to stick inside the fuel resivour? Or get plugged. Seems unlikely because of the amount of fuel that poured down my arm when I changed the high pressure pump.

 

Some of those fuel reservoirs have a filter inside of them....

 

I spun the bottom off it thinking that there was but there wasn't. I'm wondering if there was something in the new tank that's plugging up the inlet sock on the pickup tube. Running out of ideas.

 

So if just like to finish up this thread incase it help somebody in the future. Finally had time to work on the bronco. Started at the tank. Removed it and cleaned it out. Wasn't dirty but had to try something. Tested the In tank pump was good. Blew the line out to the fuel reservoir and it seemed fine. Removed the reservoir and found crud plugging up the little check valve in there. So cleaned that all out and it's night and day now. All good. I actually just got rid of that check valve completely. There is one in the high press pump anyways. She has lots of power now. Thanks