idling a little off

[armyhorse86]

so ive got an 86' bronco 2 with the 2.9 liter, whenever i have the truck idling it sounds like it is misfiring. ive checked all the plugs and even put a timing light on it and it seems to be fine, as it idles the motor shakes just a little more than normal. could it possibly be a bad valve? or something else...

 

[armyets2003]

i have a few suggestions, but there are many things that could cause what you are describing. Vacuum leaks, bad motor mounts, cracked/corroded distributer cap and or rotor, spark plugs and or wires, and dirty injectors, among other internal components. that being said my 87 seems to do exactly the same thing you are describing. i racked my brain and tested this and looked at that till i was crazy. i had always suspected the injectors were just really dirty but it wasnt confirmed until i installed a propane system on it. it runs perfectly while on propane but goes back to the same when running gas. start with looking at your vacuum hoses after this many years, they are surely very brittle.

Shawn

 

[armyhorse86]

ill definatley check out the cap and rotor, all of the vacuum lines seem to be fine. I also forgot to mention when i hit the gas pedal it has a slight hesitation at first

 

[armyets2003]

oh yeah i definitaly have hesitation running on gas. it started out barely noticable and just got progressively worse over the last 3 or 4 years. it makes it hard to work the clutch right on start off. sometimes i guess right on the hesitation sometimes i end up reving the hell out of it cause i wasnt quick enough. its a guessing game. no problems with it running on propane though. i just need to break down and buy new injectors. good luck i hope its something obvious and inexpensive.

Shawn