BToxic

So I've been poking around here trying to find others with similar problems before I posted myself. Either my Google-fu is weak, or it's a unique problem... my guess is the former.

So my truck idles fine, and revs fine, but on the highway when cruising at about 2800-3100RPM it has a tendency to, i don't know, hiccup, or cough. I could imagine that it would be like having air in fuel line.

I had a much more pervasive problem a few years back that turned out to be a issue with the mass flow sensor ( found by flashing the code ).
I did find the O2 sensor to have a broken stud and gasket leaking exhaust out.... I was hoping that was the problem, but I fixed that, and the problem persists.
I've replaced the plugs and wires because the old ones were crap, the distributor looks fine.

I don't get any error codes, either.

I just wanted to post here before I get too much deeper into the repairs....as I just did a massive project re-gearing it.

I'm thinking that the fuel pump may be on the way out, but I'd rather have my suspicions confirmed.

Thanks for any info.

jb451

BToxic, have you checked your spark plug wires to see if any are burned, corroded, or cut? And also that they are making contact with both the distributor and plugs? Chased a problem like that for weeks, found out a plug wire was slightly burnt... Could also be a vacuum leak?

MudHippy

Yeah, it's a rare one. But not unheard of. Lots of threads on it. They're just hard to find. Here's one https://www.yotatech.com/forums/f116...e-nuts-186678/

But you should read this article first http://www.motor.com/article.asp?article_ID=271 . Since the issue is most likely the one discussed therein.

BToxic

Thanks for the information....

jb451-
I know it's not the ignition cables, as i already chased that possibility by changing them all. I did take a second look, this morning, and they seem fine. Vacuum hoses seem fine, but I'll take a closer look at everything plugged into them. I helped a buddy trace down a leak in his Astro by using propane vapour.... I may try that again.

MudHippy-
Thanks for the links, I will read through them.

Cyberman

Just wanted to chime in and say that I have the same problem, and have had it for years.
Runs fine, but will on occasion, die, then recover, all in a split second. It skips a beat, and causes me to skip a beat as well everytime it happens.

I haven't tested the VSS theory. One of these days I might though.