Morning,

First post here...

I've recently become the owner of a family "heirloom"...my dad's 89 RS.

I've searched (exhaustingly!) on this issue, but I couldn't really find any clear answers (and come conflicting ones as well!)

My main issue is that once it's really warmed up (about 30-45 minutes of driving), RPM's are dropping dramatically at idle when in gear...to the point where it will frequently stall.

She hasn't gotten a lot of driving in the past 3 years due to some health issues my dad was having..not that it was ever driven frequently / hard anyway...only about 70k original miles over 23 years...isn't alot of mileage.

For about the last 6 months, she was sitting with the battery disconnected. When i reconnected the battery, it was realllly hard to get started. Plenty of crank..just wouldn't catch. Had to pump the pedal to get it started.

That's when I noticed the hot idle problem. Searching on that topic lead me to possibly having screwed up the "idle relearn" by pressing the throttle. Then I read other threads that said this car/motor didn't have an idle relearn. So i erred on the side of "it can't hurt anything", so I disconnected the battery for 10 minutes and was going to try it anyway. But when I reconnected the battery, i had the same problem as the first time i hooked up the battery.

Sorry for the long dissertation, but my main question at this point is..does this motor have an idle relearn process, or does it just build that profile from driving? If it does have a true relearn process that I need to follow, any ideas on why it's next to impossible to get started after a battery reconnect?

Any help that anyone may have would be greatly appreciated! This is a great site and a wealth of information, so I plan to re-visit often!

Thanks in advance!

 

Iv got the hot idle issue aswell, I'd like to know what causes this and how to cure it if you find an answer

 

evilemodkid94 - there is a wealth of info out there on the warm idle piece. Most of it centers around the IAC and TPS.

My issue is, I don't want to take a bunch of unnecessary steps (that could mask the actual problem / make it worse). I think the hard to start after reconnecting the battery is symptom of what's really wrong with mine, but I can't be sure. There's a lot of differences between model years (especially the 89 2.8s's) so it's hard to get a definitive answer.

 

no idle relearn on the 2.8, thats only on the 3.1 and can make driving it a real pita until the idle relearn is done

its only hard to start the first time after disconecting the battery??then fine everytime u try to start it after?

whens the last time the car had a full tuneup?


full tuneup is were i would start if it hasnt had one done anytime recently


also do u get a check engine light at all?

 

project89 -- thanks for the definitive word on "idle relearn"! I did a full tune-up on her last summer, so I don't think that was my issue.

I decided to just go back to the start and retrace my steps from the day before on the off chance something got missed. Disconnected the battery, then pulled the IAC and clean it again. I then took a long q-tip (the kind that people used to clean the heads on old tape decks), sprayed it with throttle body cleaner, and cleaned out the IAC passage (all the same things I did before)....but this time, a nice chunk of carbon came out on the q-tip. I had gotten some out the day before, but this was a nice sized "sliver".

Buttoned her all back up and reconnected the battery. Fired right up! Now not only is the cold idle solid as a rock, the warm idle is 100 times more stable than it was. Still reads a little low on the tach (half a needle width below 500rpm), but I can't necessarily rule out the tach on that one. The gauge cluster is not the original and is from an older year (only has 85mph).