low RPM etc.

ok i may be hasta , but i need to know a few things.

1; even after takin my 89 limited to the garage it still has extremely low RPM's (i'm talkin the first line at idle).

2; because of #1 problem she stalls when i let up on the skinny pedal. (not a good thing).


it almost feels like she may need a new fuel filter/pump (in-line filter or in-tank on pump? or both?)
also since this started (yes i've asked about the tps on other sites, it's fine. even had the throtle turned up). it's almost like the ecu (darn computer:flamemad::badpc: ) isn't workin correctly. it is almost 20 years old after all .

also just out of my own ebil couriosity..... can an OBD 2 computer (out of a newer 1993+ 4.0 jeep) be plugged in to an OBD 1 (i.e. to replace ) with out a bunch of b.s. switching out other junk? meaning are they the same plugs or do they need to be replaced as well?

not sure if the electronics are going south on here or just the filters. not lookin to drop a bunch of cash on tryin to get her running right. (don't have it to drop).

got to get her running right before i can even think of doin any "fun" up-grades to her.


thanks & good wheeling to all that respond.:wave:

Hey there lust outta curiousity what were your readings when you adjusted your TPS? Also I have had several computers fail and one thing remained the same about them, that is I lost multiple outputs at the same time not just one thing or another. Check this site out: http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm
and if you find somehting funny repost or even if you fix it repost. I am interested in what would make it run like that.

not sure what it was when she took it in. i was at work when she took it to the garage. just told her that they turned it up. i didn't replace the TPS, just put the old one back on before it went to the shop.

on the way home just now it still idles at 0 rpm's.

bump.

back in january i replaced the CPS (crank position sensor) so i'm pretty sure that isn't the problem.

Stihl029 thanks for that link.

have you read the "RenX Files" thread yet? If not search Ecomike" and RenX Files" in the OEM forum.

I would not count on someone else setting the TPS, or even Testing the TPS correctly, not even a stealership. It could still be part of the problem, but more likely it is trash, carbon, in the Idle Air Control circuit of the throttle body, and a stuck Idle Air Controller motor, IAC, along with possible ground wire problems and possible Bad TPS behavior. Maybe even a bad return signal wire back to the ECU from the TPS.

The Renix ECU is nearly indestructable. Only failures we have heard of were bad fuel injector firing transistors on the board, and only 2 of those that we know of.

Time to get an analog volt ohm multimeter and start checking readings on the TPS, probably need to pull the throttle body and IAC on the throttle body and clean both. Also reoil the IAC.

I have found that spraying carburator cleaner in the IAC port on top of the throttle body, and through the butterfly, while the engine is running is a good 6 month maintenence step to limit the build up of carbon gunk and to free a not too stuck IAC. I severally stuck IAC needs disassembly and major cleaning, or replacement, followed by major solvent cleaning of the throttle body.

Also, after doing any ground wire repairs, the TPS MUST BE recalibrated, or it can cause your low idle problem. After recalibrating, disconnect the battery for 1/2 hr, reconnect the battery, start and drive it to let the ECU relearn the new TPS settings.

no i haven't yet EcoMike, i'll be sure to check it out though.

at this point my girl-friend is about ready to "drive it over a cliff".
i chuckle at that...it may run better if she did!!!, roflmao. (gotta treat it like it was meant to be treated, like a 4x4!!!). (but i'm a former 4x4 ,dodge ramcharger, owner too)

i just need a good (non busy) week-end to dig into the jeep & fix it. then i'm sure that i'll have her fixed & running right.

Yeah, double check the TPS... Here is a great link for that:

http://wagoneers.com/XJ/tech/TPS-adjustment.html

Also, if you want clarification on the TPS, Here is a great zip file that has the step by step in an adobe format:

http://www.lunghd.com/Downloads_and_Links/Adjusting_TPS.zip

Also, the EGR valve on our renix are junk! Mine runs 10 times better after I capped it off, and I didn't have to pay 90-140 dollars for a new one! You might want to try that.