I have the 2000 4.0 OHV. It has just about 101K on it. Over the summer, I noticed that when I would crank it, it would sometimes idle real low (tach at 0) and the volt meter would falter. On the way to summer camp (Wisconsin from Florida) it did this for quite a while one morning until I got on the road a ways, so I swapped the battery as it was shown to be dying. Durring camp, it started doing it again, so I had the alternator checked thinking the problem electrical. Alt seemed fine. Took it into a shop and was told it needed a tune up. New plugs gapped right, new wires and the like dropped in. Ran great! For a while. Still continued to do it from time to time. This afternoon (rainy all day) I get it and it does it all the way to the movie store. (Get out of car, check out under hood, slam hood in frustration.) Come back out of cideo store and all is smiles again.

I've read everything from IAC, to vaccum lines to MAP sensor. My buddy checked it with his OBDii and it popped no codes out. When it runs great, everything if fine. (Little rough idle here and there) but I'm at wits end with this thing at points. How do I get this thing to run smooth? Could the coil be bad (don't recall if it was changed)?

Any help would be greatly appreciated.

Thanks

Chance

 

Double check the torque on the lower intake bolts.

 

"It seemed fine (alt.)" Was it checked out to be fine?

Is a wire grounded someplace? The electrical to alternator and to the coil pack good? Ensure good connections...it's tedious.

Have you checked all your hoses, EGR/valve/canister (3 parts) & related hoses...one of those could be bad.

https://www.ranger-forums.com/forum2...d=1#post768923

 

Thanks for the replies, folks! I'll be checking everything out this weekend if I can.

Also, would a vacuum leak lead to the brakes acting strange. (Strange as in the case that you can press them down sometimes and it slows the car vs. pressing them down and almost locking them up and sitting on the dash.) Could this all be connected to the vac leak from the fuel rail/ intake manifold posted previously?

Chance

 

Well, I finally got tired of the hesitant idle this weekend and then had a gas cap light thrown on Thursday afternoon. (As I kept it running to get home.) Checked it with a reader and no code came up. Next morning, I checked it cold, just to be sure, and it cranked right up with no hesitation. That afternoon, same old thing.... hesitant and stumbling. I decided to swap the IAC. DAYUM!! Workin' GREAT now! :) kinda runs up a high idle at start, but then settles down after a minute or so. I'm happy as a clam now! Now I can go back to working on the VWs and not feel guilty that my truck isn't running right.

Thanks again for the help folks!

-Chance

 

i was going to say check the pcv and the hose going to it, but i see you got it fixed.

 

I did check those first and they were fine too. The post about the cracked pcv seal made me do a double check.

Thanks,

-C

 

the elbows on the pcv hose like to split and cause problems.
that or they get really thin and suck them selfs closed at higher rpms.