• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Renix help.

Gunter

NAXJA Forum User
Location
Aurora, Colorado
so i ll keep on sunday with it and it's running like crap.
i need it working sunday, next week or next weekend. i dont want to spend 300 dollars in sensors till it runs again.
i have some money now and will have more next friday. i dont want to take it to a shop and listen to the non sense of the other 99 problems it has. i need it to run so i can get to work. i can repair as i go but i need the Jeep to run right. I need to stop being stranded, i need to be able to drive and not worry about it shutting down. I need to not ruin my engine.


who wants to earn some post superbowl cash? :helpme:
 
1988 with 4.0 and aw4
only works at full throttle barely.
only have 3rd and 4th gear.
all the usual TPS issues, but that is not it.
fixed the splices in the harness, they were confirmed as cause of voltage changes at the TPS when the harness was moved
all of my TPS adjustment is right, and always it stays with high idle. re adjusting doesnt fix it.
cleaned all the engine area grounds except the one on the head. i need a deep socket, i can do that at work monday.
the engine runs strong at WOT and does not out run the fuel supply. so i dont feel it is a fuel system issue.
battery and alt work fine.
starting is fine
it usually works better when cold. and gets worse as it gets hot.
before this, only issues were low idle and it would get into high gear quickly. all 4 gears were available. shifted firm and no slipping, and has a small leak in trans cooler lines
 
ok have some info here for it. found some defects and fixed them. have some functionality back.
here is what i checked
map sensor voltage is 5.06
engine quits when i unplug map sensor.
IAC has 9.3 V at term B
TPS the new one, i could not get the required voltage setting so again, i go back to the original one. it is at 4.96 in and 4.09 out and .82 also the used one voltage changes smooth thru it's range. no dead spots.
CPS has 3.53 V and intermittent Ohms reading of 1 to 12 and back to 0. i have a spare i ll swap in.
02 ? i thought i was checking it, but it was an un connected plug to something else. I did connect the 02 and moved on.
Block temp sensor reads 5.02 V and 378 Ohms
did not check knock sensor or intake air temp as those are not available for replacement. or maybe just the intake air sensor?
gave the wires a look and feel, did not find any holes or melted spots. checked voltages again and wiggled harness and watched to see if voltage changed, it remained steady.

i still have high idle
my cat is not clogged. cut it off and checked with Mk 1 eyeball.
no more popping out the intake.
dist cap was moist and washed it out with thinner and dried it after wiping dry. also the rotor button and contact was all eff'd up. fixed it, will replace on friday.
was not able to check 02, cylinder head ground or sparkplugs.
trans now goes thru all 4 gears.
it runs ok when cold, as it gets hot it goes crappy and then will strand me if i shut it down. takes about 30 to 45 mins to cool down and re start.
shifts down and up.
cps voltage goes up slightly when engine is running.

question
can stuck egr cause my high idle? and maybe i need fuel pump? or check FP pressure.
 
Last edited:
it runs ok when cold, as it gets hot it goes crappy and then will strand me if i shut it down. takes about 30 to 45 mins to cool down and re start.
.
I have an 88 also....years ago my problem was the Ignition Control module. Something you might check.I didn't see that listed in your searching...but I coulda missed it.
 
I diagnosed an ignition module that stopped working when it got hot. The people I was helping had it bench tested three times, when it was cold...

The high idle may well be a different problem.

Scott, I have an extra ignition module you can try. Just don't laugh when I pull up in my wife's Hyundai. :D
 
Did you spray motor with brake lean/ intake clean near intake to check leaks causing bumped idle?
 
I diagnosed an ignition module that stopped working when it got hot. The people I was helping had it bench tested three times, when it was cold...

The high idle may well be a different problem.

Scott, I have an extra ignition module you can try. Just don't laugh when I pull up in my wife's Hyundai. :D
maybe i can try it next weekend?
 
ok i have some new information here. and new problems.
after work, my Jeep died. turned out to be rubber line in tank came off the pump.i re installed it, and then checked fuel pressure. it was at 17 to 18 psi. now at 35 .
next up i was given the wrong sock filter, so will just go with out as an emergency solution. i ll check fuel pressure again after filter replacement.
also have a vac leak from yesterday. i ll track that down and repair.
i still have high idle
i still have all 4 gears shifting up and down properly :)
i got a new ignition module, in case i need one. and i got a new fuel pump if it turns out i need that as well.
i repaired the hard plastic line for the MAP sensor. i am wondering if the repair is interfering with correct MAP sensor operation? i used 3 layers of heat shrink to fix it.
 
Did you try the suggestions above?
well actually no, but i did find a vac leak. my egr is jacked up. the metal tube that connects to the diaphram is blowing exhaust gas and the bottom of the plastic is gone, no place to re connect the vac line. what do you think of egr delete?
 
Back
Top