97 XJ sport 4.0 hard start when cold

[xj4wheeling]

Hi this is my 1st post bin a member for about a year or so lots of good info.Anyway I picked up a 97 Cherokee sport for my doter this summer and its bin running fine up to this past weekend .The colder weather seams to have an affect on it. If its bin siting for 3 or moor hours it starts right up know problem but if you take short trip it dose not want to restart seams like its flooding found if I put the gas pedal to the floor and turn the key it would catch and start.This doesn't seam to be a problem after the engine warms up.Could this be caused by a bad TPS,IAC,MAP or O2 sensors?Any thoughts or ideas would be appreciated. Thanks

 

[SteelHeadz]

Check the T.body first. See if it needs a thorough bench cleaning specially the IAC.

 

[xj4wheeling]

hey Mikey thanks for the feed back. This past June I had to change the head gasket so why it was all apart I cleaned up every thing including the throttle body and changing all the vacuum hoses valve cover grommets and vent and breather.I checked the throttle body anyway and it still looked clean no carbon build up. I was reading about the operation of the IAC and got to thinking if the IAC was not operating properly sticking or something it and closed it would probably start on initial cold start but try again before the engine warms up and the IAC is still closed you would be completely choking off the air to the manifold and the injectors would be squirting raw gas hence the flooding and hard starting.What do you think ? also I just remembered I had a old throttle body off my 94 so I pulled the IAC and it gets pretty gunked up in there I must confess I never took off the other one just cleaned it through the slots in the throttle body so it mite not have cleaned it that good . So you where probably right. Thanks

 

[54cj3b]

Hi this is my 1st post bin a member for about a year or so lots of good info.Anyway I picked up a 97 Cherokee sport for my doter this summer and its bin running fine up to this past weekend .The colder weather seams to have an affect on it. If its bin siting for 3 or moor hours it starts right up know problem but if you take short trip it dose not want to restart seams like its flooding found if I put the gas pedal to the floor and turn the key it would catch and start.This doesn't seam to be a problem after the engine warms up.Could this be caused by a bad TPS,IAC,MAP or O2 sensors?Any thoughts or ideas would be appreciated. Thanks

just messing around with a few mis spelled words
don't take it the wrong way just playing a little no offence

Bin = Been
Doter = Daughter
Moor = More
dose = does
Seams = Seems

OK seriously now

First I would check the timing , Than plugs ,wires etc , if nothing bad there unplug map while running see if theres a change in way it runs if engine runs rougher the map is OK ,plug map back in and go to the next step, check if there are any loose connection on tps or possiton could be off if no loose connection and if positioning on sensor is ok its probably a bad tps and usually o2 sensor goes at same time this should give you a good start in finding the problem :roll:
Also check all your vacuum lines making sure there all conected

 

[SteelHeadz]

I was reading about the operation of the IAC and got to thinking if the IAC was not operating properly sticking or something it and closed it would probably start on initial cold start but try again before the engine warms up and the IAC is still closed you would be completely choking off the air to the manifold and the injectors would be squirting raw gas hence the flooding and hard starting.What do you think ? also I just remembered I had a old throttle body off my 94 so I pulled the IAC and it gets pretty gunked up in there I must confess I never took off the other one just cleaned it through the slots in the throttle body so it mite not have cleaned it that good . So you where probably right. Thanks

So did you fix it?, was it the IAC?.

 

[xj4wheeling]

Hey Mikey thanks for the ribbing on spelling I deserved that one,so much for spell check. Any way my daughter has the jeep at College and wont be home till the 19th, so I plan on working on it that weekend .I think I'll drop the $40 and through in a new IAC.I also have to change the rear brake line from the master cylinder back. Looking a little to rusty for my liking.Same thing with the vapor line off the gas tank I was getting a check engine light code 31 evaporative control circuit, some times the gas cap but the vapor line is rusted to hell.Well it looks like a up coming weekend of wrenching.