fredgr: I believe so.

Cherokee54: Popped the cap, and although externally it looks new, inside it appears pitted. Ditto the rotor. I will pick up the son from work and run down and check on Nick, see if he still grieves. Well, and pick up a distributor cap and rotor.

 

Well, who would'a thunk parts stores close early on a holiday? I will hopefully score the sought-after replacement parts tomorrow, although The Wife wants to go to Fish Creek and commune with fossilized sea bottoms, so we'll see. Thank you for your input. Keep it coming.

 

Just make all left hand turns and don't use brakes ...lol...

 

Thank you, freedgr. I will check this out.

 

Cherokee54: Replaced the cap and rotor. It still bucks. Any other suggestions?

 

I've been working on this most of the day, and I have several more observations. When below forty-five miles an hour, sustained distances, it doesn't buck. Get on the freeway, get it up to cruising speed, and its kicking all over the place. I really do need help.

All Help Greatly Appreciated,

 

Try a different MAP sensor, sometimes they work at idle and low speed but fail at sustained or freeway speeds.

 

I'll try that highmileage. I wish I had the equipment to check it first, though.

 

You could check your TPS to see if it is adjusted correctly and has no dead spots. Cruiser has the procedures in his pink link.

 

You can "borrow" one off of a Chevy to check, if available, same sensor.

 

I hate to admit it, but I took it to a shop. My wife knows the owner. They replaced the crankcase sensor, that wasn't it. Then they tore into the ignition wiring underneath the dash. They didn't see anything out of place, but then they took it for a ride on the freeway, and the problem was gone. So they apparently fixed it, but they don't know how. They told us to take it home, and if the problem didn't return, we could pay them.

 

We took it out to the desert for a camping trip. It overheated getting there, but once we settled in, we took it down Carrizo Wash. South Carrizo Wash Road had reached new heights. It wasn't fine sand, it was silt. The mound between the two ruts was eight inches tall, and six inches after we plowed through it. I've owned a few four-bys before, but I've never felt such a solid low range pull, ever. I slipped it into low-range, and the damn thing nearly bellowed, 'I'm Home!'. When you'd come out of the dry silt bog, and the front wheels hit solid(er) ground, it jumped forward.

Now, about the over-heating. It doesn't appear we're boiling off that much water. The auxiliary fan doesn't seem to come on until its already running hot. Is there a way to adjust it do it comes on at a lower temperature?

 

check/clean you vehicle speed sensor (vss) and after that I'd check for bad grounds, run a new ground

 

Throttle position sensor? mine did that almost thought the tranny was going out....

 

Mine would only buck at 25 mph sometimes not at all but that sensor can cause all kinds of symptoms bucking/hiccuping being a main one