Anybody else ever deal with this? Wnenever I let off the gas pedal the idle drops low, into the 250-500 RPM range. It recovers after a second or two and then its fine, but sometimes it dies completely and I don't notice it until I try to steer or look at the tach. I don't think it has to do with the brake booster as somebody else mentioned to me, because it doesn't necessarily happen when I hit the brakes, just when I let off the gas too fast. Anybody have an idea?
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Idle drops when I come to a stop
- Thread starter Adam96
- Start date
I know that the TB is looking good, I just cleaned it not too long ago. But I'm not quite sure about the IACV, I guess I could look at it and see if it looks gunked up. You think just good old carb/intake cleaner to clean it out or is there something better? Could this problem be because of anything else?
From what I have read on 
, regular TB cleaner should be OK for use on the IAC. I am troubleshooting a problem similar to yours, so this will be my first step.
In addition, when was the last tune up? My Jeep would idle very low and one time stalled out upon putting it in drive, but after changing plugs, cap, rotor, and wires, the problem got much better.
, regular TB cleaner should be OK for use on the IAC. I am troubleshooting a problem similar to yours, so this will be my first step. In addition, when was the last tune up? My Jeep would idle very low and one time stalled out upon putting it in drive, but after changing plugs, cap, rotor, and wires, the problem got much better.
Davesxj
NAXJA Forum User
- Location
- Orlando, Florida
CEL on?
I'd check out your TPS. Mine started dying at stops recently ... all it took was taking the TPS off cleaning it up, a few tap taps, and replace. Doing fine so far.
I'd check out your TPS. Mine started dying at stops recently ... all it took was taking the TPS off cleaning it up, a few tap taps, and replace. Doing fine so far.
BruceB83
NAXJA Forum User
- Location
- Dacula, Georgia
Throttle Position Sensor.
I'm having the same problem. I recently replaced my TPS so that's not it in my case, but could possibly be in yours. I'm replacing my IACV next. IACV is the Idle Air Control Valve. I think a bad IACV usually causes high idle and/or a high idle spike when the vehicle is started (which mine does). I'd be willing to bet it's the IACV. Do you have occasional high idle on start?
I'm having the same problem. I recently replaced my TPS so that's not it in my case, but could possibly be in yours. I'm replacing my IACV next. IACV is the Idle Air Control Valve. I think a bad IACV usually causes high idle and/or a high idle spike when the vehicle is started (which mine does). I'd be willing to bet it's the IACV. Do you have occasional high idle on start?
rooneypower
NAXJA Forum User
- Location
- Woodinville, WA
Its your TPS and/or MAP sensor. Just take apart your throttle body and clean it all out with some paper towels and degreaser..
That is what worked for me..
That is what worked for me..
BruceB83
NAXJA Forum User
- Location
- Dacula, Georgia
Wait...what year is your XJ? Remember to post that, it makes a difference.
If it's a RENIX, it could also be a bad gound strap. Also, check the positive cable coming off your battery going to your starter motor relay. Do a search for "renix" if that is what your's is.
If it's a RENIX, it could also be a bad gound strap. Also, check the positive cable coming off your battery going to your starter motor relay. Do a search for "renix" if that is what your's is.
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Nope not a renix. Mine is a 96. The CEL is on, but I have a scanner and it comes up as 'manufacturer controlled transmission'. Whatever that is...anyways, I think I'm going to go ahead and clean everything out and see if that makes a difference. A throttle body spacer or a K&N FIPK wouldn't make a difference would it?
