PDA

View Full Version : Idle/random issues also



Prerunner06
04-21-2016, 08:31 AM
I recently put a new header on my 96 xj 4.0 last one was cracked. In the process I cleaned the throttle body and IAC. After installing the header I have a odd idle issue. It idles at 1k but if I pop the throttle coming up to a light of press brake and pop throttle it will settle down to 700/800.

My other issue that just came back after a while. Is I had my a/c on yesterday and while trying to pass someone my Jeep acted like it was in nutruel when it tried to go into OD. I then realized I wasn't going into OD and the sec I shut the AC off the Jeep shifted into OD!

Are these problems linked or am I hunting for 2 separate issues I am at my wit's end with these issues.

Already tested for vac leaks there are non new IAC was installed (last one was corroded) everything else on the Jeep works great just the odd idle and AC/transmission issue

Sent from my XT1585 using Tapatalk

nickyg
04-21-2016, 08:39 AM
I've heard that the neutral safety switch controls the overdrive on some years.
But That's not confirmed, just water cooler gossip.


Sent from my toaster using Tapatalk

4.3LXJ
04-21-2016, 10:54 AM
When you cleaned the throttle, it is possible your throttle position sensor didn't like it. Since you tap the throttle and it settles down, I think it might be time to replace the throttle position sensor. Not sure on the AC thing though. Having it on sometimes affects idle speed, but shouldn't affect the tranny, unless again it is the throttle position sensor affecting the shifting of the tranny. It does do that and a damaged sensor is probably the culprit there.

Prerunner06
04-22-2016, 08:45 AM
Small update.

Tested the TPS it did lose voltage in the same spot at 3/4 throttle. Got a new one and jeep ran better at the initial start up then something started to calibrate and my idle started to adjust settled down to 600-700 rpm took for a test drive was driving fine. Got home idle back at 1k put it in park 1500k. I blipped the throttle idle settles down to 6-700.

Also at the tail pipe the idle sounds odd almost like a miss fire but not as harsh don't know if it's the new header or just part of the problem.

I am still looking for ideas is it possible my throttle body is hanging up?

Sent from my XT1585 using Tapatalk

4.3LXJ
04-22-2016, 09:40 AM
Steve, these Jeep ECM are kind of stupid. Takes them awhile to learn when you change something. You might try to reset it by disconnecting the battery terminals and touching then together. Don't be surprised if it runs a little weird for a day or two afterwards though. Like I said, kind of stupid