Surging Tachometer 97 6cyl

[anthropisces]

Folks,

 

I'm having surging problems with a 97 pathfinder that I bought about a year and a half ago. I'll be driving down the highway (or sidestreets for that matter) and the rpms will rapidly climb (surge) for some period of seconds. I generally have to accelerate (up or down) to stop it and then it will be fine for some period of minutes afterwhich it will repeat.

 

It began doing this soon after I bought it and then the problem seemed to lessen for awhile (at least that's my recollection) and lately it seems to be doing it again. It will do it on local roads as well.

 

Can you offer me any advice?

 

Thank You

 

Anthropisces

[88pathoffroad]

Do you have any ECU error codes? Try the simple things first. Look for missing or damaged vaccuum hoses, clean the throttlebody and MAF sensor, check your air filter, etc. Done a tune-up recently at all?

[mikemike]

fuel filter??

[4x4le]

^^^^^^probable not

 

Im sorry guys, I have seen so many of these posts and I always forget that I fixed this peoblem befor on my old 89 240. I had to replace the resistor on the tach wire. I dont know if the pathy has a setup like this, but I guess you could ask the stealer. It wasnt high, like 10 or 15 dolla. And It would be a dealer only item anyways.

Edited January 25, 2007 by 4x4le

[anthropisces]

4x4, did the rpm's related to your problem actually climb or was your tach reading simply unstable? My engine RPMs are actually climbing. I'm not simply seeing my tach needle climb and fall.

[anthropisces]

I want to thank everyone posting. If there are any additional suggestions, I will be very glad to get them. I intend to adopt a staged, shotgun approach. I'll try everything until its solved.

 

I've never tuned it up, so that'll get done.

 

I'm going to clean the egr valve too.

[4x4le]

It was not linier to my rpms. It would sit on 0 and then when I gave it some gas it would budge a little. When I would gouge on it it would clime maybe to 4k at the most and then when I would hit the rev limiter it would read higher than the limiter was actually set at. It would bounce from 8 to 0 during revlimiting. It was kinda neat lol. I cant remember what I was telling people but I had some stupid story made up that I modifed it that way and it was telling me something I made up about the engine. People believed me because as a kid I knew alot more about cars than my friends did.

[anthropisces]

Fixed It![/b]

 

The surging problem I was experiencing is gone, thanks to a new Throttle, Position Sensor. Ironically, I've been having this problem for awhile and only just recently felt that the TPS was the most likely culprit. A couple of days before I went to buy the part, the check engine light came on. The error code generated was for a TPS. I bought one for $82.00, disconnected the battery, noted the position of the old TPS (there is some adjustment possible that is sort of like and advance-retard type of thing, depending on how you mount it). Reconnected everything and wah-la. The problem is solved. She rides like a dream.

 

EXCEPT for the diabolical rocking from side to side. I'll be installing new poly-bushings all over the rear linkages shortly. I'll keep you posted.