[cadeucsb]

When the jeep sits outside all day on a day like today (below freezing all day)...I go to start it, it struggles to life and I have to give it gas to start it up, then keep gas on or it dies. When its warm out, or its in the garage, I dont get this issue.

I sit there giving it slight gas until its up to temp, but even at temp when I go and let off the gas, it sputters on its way to dying and will die if I let off the gas. Now if rather than letting it die, I just shut it off (after getting up to temp) and start it back up, it starts right up and runs fine.

Its strange that its running, up to temp and still requires gas to constantly to run, but if i just restart it, that issue goes away. Seems like a really odd issue to have a simple restart just cure it.

I have replaced the plugs, wires, batteries recently. I havent cleaned the IAC yet and still intend to. However I wouldnt think the IAC would want to kill my idle, then just work again without issue after a quick restart...same goes for the battery and most electrical parts I would think.

Anyone have thoughts? If it died every time, I would think the IAC was sticking in the freezing, but being that a simple restart solves the issue, it seems a bit more odd.

[cadeucsb]

any thoughts? I am fairly baffled.

[JeepNE]

TPS maybe?

[gcfishguy]

I'd guess (and it's just a guess) your coolant temperature sensor is shot, reading wrong at the cold end of the scale.
Post up to your local club, see if someone has a scanner. Park it outside, start it up and check the reported coolant temperature with the scanner. If it's not reading close to ambient temperature, that's the issue.
If the temp sensor is at fault, it's likely reading hot when it's actually cold, and it's running lean when it should be rich.

[austentatious]

i had this happen to me once because i left my lights on all day during school and the jeep had to "relearn" everything. such as the idle

[cadeucsb]

Originally Posted by ausTJ01

i had this happen to me once because i left my lights on all day during school and the jeep had to "relearn" everything. such as the idle

yea, its almost as the ecu needs a reset after its warmed up to remember how to function...but very strange.

[cadeucsb]

Originally Posted by gcfishguy

I'd guess (and it's just a guess) your coolant temperature sensor is shot, reading wrong at the cold end of the scale.
Post up to your local club, see if someone has a scanner. Park it outside, start it up and check the reported coolant temperature with the scanner. If it's not reading close to ambient temperature, that's the issue.
If the temp sensor is at fault, it's likely reading hot when it's actually cold, and it's running lean when it should be rich.

would I see a difference on the temp gauge on the cluster due to a bad coolant temperature sensor? I assuming this is different than the coolant thermostat which definitely would register on the cluster ....time to research.

For $15, assuming its easy to get to, ill probably just replace it and see what happens next time its cold....then move on to the TPS etc in the future.

[cadeucsb]

gcfishguy, I think you may be right on....

From the manual: "The sensor provides an input voltage to the PCM relating coolant temps. The PCM uses this input to determine proper operation" ie: warm up mode via idle mode.

So my thought is the temp sensor isnt relaying the cold conditions as you said, so by me keeping it alive until it warms up and then restarting the car (thus restarting the PCM), it now can just run in regular idle mode since its warm.

That would explain the need for the restart...could still be the TPS, but based on the fact that the PCM needs a restart, it def sounds like a sensor reading not working properly. However if it was TPS, it should occur in any/all ambient temps.

[cadeucsb]

I replaced the ECT and picked up some throttle body cleaner for the IAC. Problem is I cant really test it until sits in the really cold weather all day.