possum Posted July 13, 2009 Share Posted July 13, 2009 I figure the P.O. disconnected this for a reason (the IAC). My question is will it hurt the truck running it without it plugged in? It runs fine and has been for the past two weeks. I am a chicken to plug it back in as I do not want to wake any sleeping gremlins. Link to comment Share on other sites More sharing options...
Geonovast Posted July 13, 2009 Share Posted July 13, 2009 The IAC is probably shot, and the PO must have done something to keep it open a little. Truck shouldn't idle at all if it's closed. Link to comment Share on other sites More sharing options...
possum Posted July 13, 2009 Author Share Posted July 13, 2009 So should I worry about it or just leave it be for the time being? There are other things I would like to service on the truck first and money is tight at this time. Link to comment Share on other sites More sharing options...
mnkyboy Posted July 13, 2009 Share Posted July 13, 2009 does the TBI use an IAC? these are usually used on mpfi systems,with the TBI fuel is shot in with the air so the TB should be cracked open at idle. if it does have one then It would be worth looking into,sounds like something happened and someone put a bandaid on it. Link to comment Share on other sites More sharing options...
Geonovast Posted July 13, 2009 Share Posted July 13, 2009 does the TBI use an IAC? these are usually used on mpfi systems,with the TBI fuel is shot in with the air so the TB should be cracked open at idle. if it does have one then It would be worth looking into,sounds like something happened and someone put a bandaid on it. Not sure... I've never owned a TBI Jeep. I suppose that would depend on if the injector is under or above the butterfly. I assume it's under. Link to comment Share on other sites More sharing options...
mnkyboy Posted July 13, 2009 Share Posted July 13, 2009 pretty much all TBIs are over the butterfly reguardless of make. I'm thinking the IAC is 91 and up MPFI 2.5L. i think we need a pic of whats unplugged. Link to comment Share on other sites More sharing options...
possum Posted July 13, 2009 Author Share Posted July 13, 2009 Pics are hard for me to do cause I only have work internet access. But the truck is an 87'-2.5-4 speed- 2WD. The part in question if you were looking from the driverside across the engine bay would be on your left hand side of the throttle body. It is a roundish black thing with a rod that looks like it would push the throttle linkage out when activated. It has a weather tight plug on the back. I don't know if that helps or not but the fountain of info that is a Haynes manual(sarcasim) describes the part as the IAC. And from searching and seeing pics of other IACs I am pretty sure that is what it is. The only problem I seem to have with the truck is rough idle on cold starts but it smooths right out after it runs for a few seconds a warms up a bit. The rough idle goes away if you give it a little gas. Link to comment Share on other sites More sharing options...
mnkyboy Posted July 13, 2009 Share Posted July 13, 2009 it looks like a high idle solinoid,carburated engines use them too it just pushes the throttle open a little when the engine is cold,once it warms up it shoud turn off. other then hard starting on cold days and ruff idle at start up you should be ok without it for now. it could also be tied in to work as a dash pot.you will know that if it stumbles when you dump off the throttle. the renix system is still kinda new to me but thats how they work in general it does make me wonder why its unhooked though,going back to the bandaid,i would still plug it in and see what happens Link to comment Share on other sites More sharing options...
possum Posted July 14, 2009 Author Share Posted July 14, 2009 That is what I am talking about in the picture. Maybe I will get brave and plug it in this weekend. It may have come loose by itself too. Thanks for the help guys. :cheers: Link to comment Share on other sites More sharing options...
1987Comanche Posted July 15, 2009 Share Posted July 15, 2009 The on on my '87 2.5L 2WD was unplugged (actually the connector had been cut off and was MIA) when I got her. The reason, as I discovered, was that particular IAC sticks and the truck became impossible to drive when it revved up and stuck (this happened in heavy traffic...not good). I unplugged it again, forced the IAC back in and it was driveable but would not idle when cold without a foot on the gas. It won't hurt the truck, it just won't idle when cold. I replaced it with a JY one a few weeks later and it's been fine ever since. They get disconnected when they die because the cost of a new one is rather high. I scored a complete AMC 2.5 TBI for $30 at Pick N Pull. If you find a Renix 2.5 grab the whole TBI system because a new injector is serious $$$ too. Link to comment Share on other sites More sharing options...
dasbulliwagen Posted July 15, 2009 Share Posted July 15, 2009 That part also bumps up the idle when the AC is turned on, if you have AC. I also have an 87 2.5 4spd, I swapped AC over, and wired everything in, and was suprised to see it move just enough to bump up the throttle when the AC kicked in. Good Luck! Link to comment Share on other sites More sharing options...
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