Hey guys, thanks in advance for any pointers on what to look at here...Well I have a 1989 4.0 renix xj, replaced head gasket, new jy head that was decked, checked if it sealed, had 1 valve seal replaced. new exhaust manifold gasket, new exhaust manifold, all new o-rings on fuel injectors, new o-rings on fuel rail. New water pump, new t-stat, new zj clutch fan, new valve cover gasket, new cap and rotor, new spark plugs, new plug wires, grounds refreshed and bought new battery cables from 5-90, new head to firewall ground cable. after I did all that I checked for vacuum leaks, no leaks, took it to smog, smogged perfectly fine. Moved out of my house and used the jeep to move everything, it ran beautifully, started up everytime, I was happy. Then it started to do long cranks like my fuel pressure was low, so I replaced tps, cps, both premium ones from NAPA like cruiser54 suggested, checked fuel pressure with a tester, my check valve was bad, bought new fuel pump- spectra premium from rockauto, just installed today. My problem is, I'm not getting long cranks anymore, but I'm still getting sputtering, stalling issues at idle, and when I floor it, it does not seem like it wants to get up and go...Not so much a sputtering, just a slight hesitation/sluggishness it feels like. Brand new fuel pump though. and theres just enough gas in it to not have fuel light come on, a bit above red. about 3 gallons. I'm kind of broke right now, couldn't afford any more fuel to really be assured that its not just low fuel condition. I'm pretty much out of ideas on what to do next, IAC maybe? I took it out and cleaned it with carb cleaner and a toothbrush when I bought the jeep about a year and a half ago...could it just be bad? Fuel filter hasn't been changed since I bought it either. Please help, I really need this Jeep running right so I can go apply for jobs.

Thanks guys

 

Light it on fire and collect the insurance money!

 

Too poor to afford full coverage sadly

 

My friend had the same issue on his 96, even though its not a renix his issue was the IAC went bad. You can take it back out and clean it etc etc. But if the actual electeonics are getting worse...then theres not really much to do about it but replace it. My friend got his at advanced for like 50 bucks, i know cash is tight but if you got a good buddy its not too big,

Other then that maybe pull off the throttle body and do a good deep cleaning...is the air filter clean or pretty dirty? You can clean it up with rubbing alcohol or anything that evaporates 100%

 

I'd clean up the IAC and see if it helps. Might check the TPS and CPS voltages too just to check for problems. Make sure no vacuum leaks have crept in.
How does it run at higher RPM?

 

Yeah iac seems like it may be the hot ticket, runs great at high rpm in park, but it just feels a little sluggish in drive at WOT though, I need to take it out for another test drive with a bit more gas in it to make sure though in the morning. Its pretty late here and my Jeep is loud

 

Drive faster.

 

If they cant appreciate the roar of an i6 at any hour they dont need to be your neighbors

 

haha true not so much the neighbors per say, one has a sweet 60's mustang that sounds beautifull. It's my gf's sister's baby is all haha

 

As soon as the gf statement was read i understood the situation lol

 

Tell her we said it's OK. It'll be fine.

 

I would try to see if a bottle of Sea Foam or Red Line doesnt help before going and replacing sensors. $8 vs more. Poor some of that in with a full tank and take it on the highway and blow it out (***** out).

Also make sure the TB is tight as not to produce a vac leak

 

Double check the intake manifold bolts. They may have loosened up on you, allowing a vacuum leak. Do you have a vacuum gauge? If so, what is your vacuum at idle?

 

Didn't think to recheck those, will do for sure when I wake up. And no, I don't have a vacuum gauge sadly

 

How did you adjust the TPS?