Hello everyone, stoked to be here. Just bought an 89 rs on ebay, drove her from twin falls Id to San Diego...she made it too. Bunch of q's please bare w/me. Her idle, after cruising for a while & she is warmed/hot tends to jump from 1000rpms to 1800-2000 rpms. This is a 2.6 by the way, if she does stop jumping she tends to hover around 2000rpm's. I can shut her off at the stop light for 20 seconds & she'll still idle high but won't jump. Any suggestions? Will ask the other q's later. Hope I'm doing this right, I'm a "newbie" Thanks to all who respond

The best initial suggestion I can make is to use the search feature. You might find answers to questions you didn't even know you had ! <img src="/forums/images/graemlins/smile.gif" alt="" />

I think a keyword like IDLE +SURGING will get what you are looking for, don't forget to set the DATE field on the search page.

How's the temperature doing? Typically from experience in the past is that when the temperature starts to creep up, it starts doing that to try and circulate the water to cool the motor. Second, check for vacuum leaks. If you don't find any at first, get the motor good and warmed up until it starts loping like that. Then go and check them. It could be that the leak doesn't show itself until warmed up to a certain point.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />

You could try "burping" the coolant system of air.

Madcat <img src="/forums/images/graemlins/kewl.gif" alt="" />

Gads, many things come to mind. Have you looked at the throttle cable "seat" at the firewall? Those plastic clips can be an issue. Is it stick or auto trans? The most significant improvement in my idle quality (after repairing dozens of vacuum leaks, basic tuning proceedures, self diag ECM,etc) was a clean and adjust of the throttle switch (TPS on auto trans units). If you have a manual box, I suggest you read Troopersphere's well written article on tearing down and adjusting this switch, my ECM never knew idle until I did that job. The old brute has manners now.
Check a few things out and post results here, perhaps we can nail 'er down.

Thanks, I did a quick search when I registered but will try agin w/ your suggested phrase. Thanks for the time! -Noel-

Thanks for replying! Initially the temp was running very (over half on the temp guage)high & that is when she would typically surge. I've since solved the high temp problems & I haven't seen the surge issue as of late, but she will still stick around 2000 b4 idling down to 1500 or so. I've only been doing city driving though & have not been on any long distance stints since bringing her from Idaho. Thanks for the suggestion & will look at the vacuum side of things as well. Take it easy. -Noel-

Thanks for the reply, will look at the "seat" & investigate. Also she is a 5spd. Will look at the troopersphere's article as well. Do you have any suggestions on purchasing one of those portable electronic analyzers, as far as which one would be best for an 89RS? Thanks for the tips & time. -Noel-

Good article, click here ...

If your search didn't find this one, check it out...

Diagnostic equipment? Zu's self diagnostics are quite enough for sensor error. Many codes can stem from the failure of one sensor though, knowing this sequence can take some time, but it's possible for all. Usually the first code confuses the ECM and sets alternate stemming codes, but not always.
I almost d'rather not suggest this, but have you tried checking head torque? My '88 2.6 had somewhat similar symtoms and a re-torque made 'er smooth for a few days. I changed the head gaskrt since and all's fine fer 3K. I would particularly like to know what the movement of the left rear head bolt is. Muh best...Cal