dick.breakey
NAXJA Forum User
- Location
- Bellevue/Seattle
89 cherokee(sport i believe) 2 door 4.0 w/ aw4. 155k
here it is. i think its vacuum actuated if im not mistaken. im having trouble with the jeep running correctly. i bought it for 350 bucks from a guy who couldnt get it to run right. from the symptoms i figured it was just a grounds issue and wanted to capitalize on his inability to properly diagnose it. before it would only run with the gas pedal pressed in and it would run very rough. would barely idle if it did idle. after a full tune up and cleaning the iac and tps, and replacing the o2 and cps sensor it now will start on its own, and idle perfectly, for a minute. then it will randomly kill its self. sometimes it just bogs down where the rpm's barely register so it shakes like crazy and then i just shut it off. if i open the throttle too fast, and i mean any faster than a CH at a time, it will instantly die, yet when i do it slowly it will rev perfectly. but most times it will die if i just let off the throttle all the way. if i step it back down it will go back to idling. so ive been troubleshooting this thing on and off, and the haynes manual has helped some but nothing this specific. so ive gone from hardly starting and no idle to starts, idles great(before it shuts its self off) and kills its self when the throttle is opened. i also have not been able to check the fuel pressure cause i dont have a gauge and cant find one for an affordable price. i might just go to harbor freight in a little bit though. anyways. so after everything, i think ive got it narrowed down to either the fuel pressure issue or this thing i have no idea what it is. the pics show where it is on the air box and this flex tube that goes under the intake manifold. what is it and what does it do? i couldnt find it in the haynes either and i have never seen one of these on the h.o. motor, so i assume its renix specific. lastly, while its running, instead of opening the throttle a little at a time, if i go WOT immediately, sometimes it will stay running, but cough real bad for few seconds and then rev up and when the revs come back down and i try again, it will pop as if its coming from the intake, but also kinda sounds like its coming from this mystery part. any help would be appreciated. i dont know the 4.0 real well, only from what ive researched and all my 4.0 buddies say.
here it is. i think its vacuum actuated if im not mistaken. im having trouble with the jeep running correctly. i bought it for 350 bucks from a guy who couldnt get it to run right. from the symptoms i figured it was just a grounds issue and wanted to capitalize on his inability to properly diagnose it. before it would only run with the gas pedal pressed in and it would run very rough. would barely idle if it did idle. after a full tune up and cleaning the iac and tps, and replacing the o2 and cps sensor it now will start on its own, and idle perfectly, for a minute. then it will randomly kill its self. sometimes it just bogs down where the rpm's barely register so it shakes like crazy and then i just shut it off. if i open the throttle too fast, and i mean any faster than a CH at a time, it will instantly die, yet when i do it slowly it will rev perfectly. but most times it will die if i just let off the throttle all the way. if i step it back down it will go back to idling. so ive been troubleshooting this thing on and off, and the haynes manual has helped some but nothing this specific. so ive gone from hardly starting and no idle to starts, idles great(before it shuts its self off) and kills its self when the throttle is opened. i also have not been able to check the fuel pressure cause i dont have a gauge and cant find one for an affordable price. i might just go to harbor freight in a little bit though. anyways. so after everything, i think ive got it narrowed down to either the fuel pressure issue or this thing i have no idea what it is. the pics show where it is on the air box and this flex tube that goes under the intake manifold. what is it and what does it do? i couldnt find it in the haynes either and i have never seen one of these on the h.o. motor, so i assume its renix specific. lastly, while its running, instead of opening the throttle a little at a time, if i go WOT immediately, sometimes it will stay running, but cough real bad for few seconds and then rev up and when the revs come back down and i try again, it will pop as if its coming from the intake, but also kinda sounds like its coming from this mystery part. any help would be appreciated. i dont know the 4.0 real well, only from what ive researched and all my 4.0 buddies say.



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