Skinner Posted January 16, 2011 Report Share Posted January 16, 2011 Just started this morning go out to start the Jeep and turns over fine stumbled to start and finely stalled out. tried it again this time will a little gas and it started and would not hold idle and stalled out. Tried it a 3rd time holding the gas and it started held the gas to keep it running and sat at 1k rpms for several min. once it warmed up is was fine no shudder and it runs smooth. turned it off make back about 5 hrs later and same thing again. Is not throwing a cel and when cold it smells of gas like its flooded out. Not sure what it is other than annoying. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted January 16, 2011 Report Share Posted January 16, 2011 Year / model / mileage? Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 16, 2011 Author Report Share Posted January 16, 2011 oh yeah that would help wouldn't it 98 Jeee Cherokee 4.0 125.xxx miles I broke out a ohms meter and tested the coolant temp sensor its within range hot and cold. Also tested the manifold air temp sensor tested out range when hot but unable to find a ohm range when cold. Was unable to test the TPS as I am by my self. Not sure if there is anything else to test. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted January 16, 2011 Report Share Posted January 16, 2011 Do you have a fuel pressure gauge? Does your Jeep have a port post-regulator? If key off and key on pressures check out, I'd check battery voltage at start and idle. Quote Link to comment Share on other sites More sharing options...
jeffro Posted January 16, 2011 Report Share Posted January 16, 2011 had this same issue with the dakota about a week ago. it did this right after the battery died. as you mentioned, had to hold the gas to keep it from dieing. after that it didnt have any issues. perhaps bad gas or water in the line. i didnt have any issues from it after that. Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 Do you have a fuel pressure gauge? Does your Jeep have a port post-regulator? If key off and key on pressures check out, I'd check battery voltage at start and idle. don't have a pressure gauge to check it with. It does have a fitting on the fuel rail I can test it with. Will look into that tomorrow but honestly I don't think that is the issue. Went out to test the battery and started right up as the engine is still warm. The battery tested fine as will 12.6 volts off and 14.3 at idle. Quote Link to comment Share on other sites More sharing options...
Not Brian Posted January 17, 2011 Report Share Posted January 17, 2011 hard start when cold that's what she said Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted January 17, 2011 Report Share Posted January 17, 2011 Cool, once fuel pressures are known, that will be half the battle. I was thinking fuel issue b/c maybe it was bleeding off while sitting, and it was taking a few pump cycles to get the pressure back up. Didn't fill up at a non-usual station this past week, didyuh? Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 Cool, once fuel pressures are known, that will be half the battle. I was thinking fuel issue b/c maybe it was bleeding off while sitting, and it was taking a few pump cycles to get the pressure back up. Didn't fill up at a non-usual station this past week, didyuh? fillup was at Kroger we always use and have gone through half a tank. Its not the gas. Also don't think fuel is the issue as normally pumps work better cold. But to rule it out anyone on the west side have a pressure gauge I can use for 5 min? Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 that's what she said look a funny one. LOL. Quote Link to comment Share on other sites More sharing options...
EvoXbmx Posted January 17, 2011 Report Share Posted January 17, 2011 You probably need to replace your o2 sensor. Hard cold start is a talltale sign of a bad o2 Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 You probably need to replace your o2 sensor. Hard cold start is a talltale sign of a bad o2 I would think a bad O2 would throw a code. Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted January 17, 2011 Report Share Posted January 17, 2011 just putting a meter on the coolant temp sensor may not tell the whole story..... with the engine cold soaked you need to put a scan tool on it and make sure the sensor doesn't read something retarded like -100 (it'll still ohm out ok at that reading) if the coolant temp sensor checks out have a look at your map sensor and tps one of them will be whacked Quote Link to comment Share on other sites More sharing options...
EvoXbmx Posted January 17, 2011 Report Share Posted January 17, 2011 What goes bad is the heater element inside of it. They go bad just enough to pass the monitor test, but not enough to work effectively. Oxygen sensors work shitty when cold, its why theres a heater in them to begin with. The element is a lot like a light bulb on a mercedes. They can be burned completely out, but the instrument cluster sometimes does not notice due to an amount of resistance still present so it does not trigger any error messages. something like that just putting a meter on the coolant temp sensor may not tell the whole story..... That too! If any of the vital sensors are out of range for a long period of time, your fuel trims are probably way high. May wanna do a "ecu reset" too. Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted January 17, 2011 Report Share Posted January 17, 2011 the pcm in that jeep doesn't reference the o2 sensor untill it reaches operating temprature Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 just putting a meter on the coolant temp sensor may not tell the whole story..... with the engine cold soaked you need to put a scan tool on it and make sure the sensor doesn't read something retarded like -100 (it'll still ohm out ok at that reading) if the coolant temp sensor checks out have a look at your map sensor and tps one of them will be whacked dave you have access to a scan tool that I can check this with? Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 got up today and it started just fine only thing different today is it's above freezing. so not I am really stumped. Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 also pulled it into the garage and heated it up for a couple hrs and he CTS still tested fine. Quote Link to comment Share on other sites More sharing options...
mjrsplat Posted January 17, 2011 Report Share Posted January 17, 2011 I had a friend with a jeep that had a similar issue. it turned out to be his IAC valve. iirc it wasnt that expensive to fix either. On my friend's jeep, he could crack the throttle open just a little bit while he was cranking and then hold it there for a minute with the jeep started, and it would make it a lot easier to start. Quote Link to comment Share on other sites More sharing options...
Skinner Posted January 17, 2011 Author Report Share Posted January 17, 2011 I had a friend with a jeep that had a similar issue. it turned out to be his IAC valve. iirc it wasnt that expensive to fix either. On my friend's jeep, he could crack the throttle open just a little bit while he was cranking and then hold it there for a minute with the jeep started, and it would make it a lot easier to start. Thats exactly what it is doing. the ICA or MAT as Jeep refers to it is testing bad (out of range ohms wise). I plan on replacing it shortly just haven't left the house today and was making sure it wasn't anything else. Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted January 17, 2011 Report Share Posted January 17, 2011 dave you have access to a scan tool that I can check this with? no it got stolen along with my van back in may got the van back, but not my scan tool. Quote Link to comment Share on other sites More sharing options...
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