Brand new motor runs but bogs down after driving a mile.

Asked by Oct 12, 2016 at 03:52 PM

Question type: Maintenance & Repair

I have an 88 bronco 2 with the 2.9 liter. It runs
great for a mile and then starts to bog down and
runs rich. I have replaced both fuel pumps, fuel
filter, distributor cap, rotor button, plugs, and wires.  
All vacuum lines are new. What else could it be?

6 Answers

Is the distance concurrent with thr speed you get to? Perhaps the carb needs adjusting to handle more fuel as youre getting up to speed. Could be as simple as the choke....

It is efi no carb

52,655

Have it scanned for codes. Could be a problem with the O2 sensor(s).

52,655

MAP sensor can cause issues also.

Funny thing is no codes are set . That's what I've been told is those 2 sensors by a couple people. Might as well change them everything else is brand new. Thanks.

102,155

It could be in the KOER test, and yes the MAP and O2 sensors are high fail on these, you may also want to check the resistance readings of the ACT and ECT sensors just to make sure they are not out of specs, I've seen these go wacky but set a trouble code or light.

Your Answer

Shortcuts

Maintenance & Repair Experts

  • #1
    Tom Demyan
    Reputation
    182,010
  • #2
    dandyoun
    Reputation
    96,120
  • #3
    tennisshoes
    Reputation
    79,830
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.