I've been reading this board for a couble of years but this is the first time posting...hope you can help... I have a 1990 Big Bronco with a 302/fuel injection. The truck starts just fine and will run fine for about 15-20 minutes, but then it starts to bog down real heavy. If I putt around on flat, slow streets, I can usaully get where I'm going. But if I have to put any speed or a hill into my driving plan, I'm doomed. I've done all the basic things(new plugs, cap, rotor,etc...)and it still bogs after 20 min. everytime. Any ideas what my problem is? Thanks

1990 Bronco XLT/302 F.I.
Flow Master exhaust

 

Sounds like your cat is clogged. Take it down to a muff shop and they can test it. you didnt say if you had an automatic or manuel but if its auto you might change fluid/ filter as well. YOu could also have a clogged fuel filter. it sits on the frame just below the driver side. might also have your fuel pressure checked as well.


good luck
later

 

I recently worked on a Ford F 150 that would bog as you call it down to 30 mph and would not run any faster until you parked it and let it cool off. The problem was the owner had recently installed a new brake master cylinder which was not the right cylinder. The pedal rod was two long and as he drove down the road hitting bumps the pedal would apply the brakes making them get hot and swell slowing the truck down to a crawl. This is the second time in thirty years I have come across this problem.

 

im no car genius and im probly stating the obvious but it sounds lke something is going wrong bc its getting too hot or something is causing it to go wrong bc of heat. just my thoughts.

 

I had a similar problem on my baby bronco, it was the tranny(a4ld) overheating. i put the biggest aftermarket cooler i could find(had to modify grill) and now a LOT less problems.
Tim

 

Could be heat related fuel pressure problems too. Any "check engine" light? Even if not, check computer codes they could yield some information or at least point you in the right direction.

 

your bronc has two fuel filters.

If the canister filter, as listed below, breaks down, you will get the same problem you describe.

1) the primary is located on the left frame rail forward of the fuel pump under the drivers seat.

2) you have a fuel dispersion canister mid-way back towards the fuel cell on the left frame rail.

REPLACE the fuel dispersion canister ( as well as your maintenance fuel filter). there are 4 fuel lines going to it. Be sure to get replacement duck bill clips. you WILL need them.

The pre-87 bronc's had a replacement filter for the canisters, however, i believe Ford has discontinued those for a non replacable fitler canister. Inside the canister is a small rubber (flap) valve that WILL go bad.

The canister runs about 20 bucks if memory serves me right.

ambrose