DIRTRIDER

Hi guys!

I have not been here for a long time and now it is a time to introduce you my another one cherokee with RENIX on board. I have bought it in july and now i am trying to do all my best and fix all bugs.

After rebuilding axles,brakes and suspension i have only one problem and this is RENIX =)

Here is a short video and you can see what is happening.


TPS is correct (0.8 volt)
IAT and coolant temperature sensors are good
Distributor cap and rotor are new,wires and spark plugs also.
Fuel pressure is good.

When i drive and when i push a gas there is nothing criminal,everything is cool. But when idling in neutral position or in a "D" mode-engine is dying=) but never shut down....

884x4

my renix was idling funny and it turned out to be my o2 sensor

DIRTRIDER

I disconnected O2 sensor only for test.Nothing changed...
Hope to find something new and fix it but i tried everything... And i still believe in miracle

DIRTRIDER

And another one question. Do you understood what i am talking in my video ? Do not forget that i am russian and my english is not awesome.

cruiser54

Your oxygen sensor could be bad. It runs the same with or without the oxygen sensor plugged in, right?

Clean your throttle body and IAC for sure.
Courtesy of TJWalker:
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The Idle Air Control (IAC) is mounted on the back of the throttle body. (front for 87-90) The valve controls the idle speed of the engine by controlling the amount of air flowing through the air control passage. It consists of a stepper motor that moves a pintle shaped plunger in and out of the air control passage. When the valve plunger is moved in, the air control passage flows more air which raises the idle speed. When the valve plunger is moved out, the air control passage flows less air which lowers the idle speed. Over time and miles, the IAC can get carboned up which can have an adverse affect on idle quality. Cleaning the IAC may restore proper function and is an easy procedure to perform and good preventive maintenance so it is never a bad idea.

CLEANING THE JEEP 4.0 IDLE AIR CONTROL

Remove the air filter cover, associated hoses and the rubber boot that goes from the air filter cover to the throttle body. Remove the IAC with a torx driver (2 bolts; one can be kind of hard to get to)

"Gently" wiggle out the IAC from the throttle body. Gasket on the IAC can be re-used if it is not damaged

Clean the IAC with a spray can of throttle body cleaner; inexpensive and available at any place that sells auto parts. Throttle body cleaner is recommended rather than carburetor cleaner as it is less harsh, safe for throttle body coatings and is best for this task. Use cleaner, a rag and a toothbrush and or Q-Tips. Be gentle; don’t twist or pull on the pintle that protrudes from the IAC as it is fragile and you could damage it.

Thoroughly spray clean and flush where the IAC seats in the throttle body with the same spray cleaner

It is also a good idea to clean the entire throttle body itself, the butterfly valve inside of the throttle body and all associated linkage as long as you have things disassembled


Make sure all your intake manifold fasteners are not loose.

Be sure the vacuum line from the back of the valve cover to the intake manifold is not split, cracked, or plugged.

Click on the link in my signature and do #1, 3, and 5.

DFlintstone

This was actualy a thread about using a meter we can access to test a Renix, (only) 02 sensor. It turns out in the process I found that a bad 02 sensor will make the idle cycle. (might also apply to OBD systems, Idk.)

https://www.cherokeeforum.com/f2/ren...ce-rms-133153/

cruiser54

I have experienced the hunting idle more than once on a Renix with a bad O2 sensor.

DFlintstone

Darn! I thought I "discovered" it! (messed up my elbow patting myself on the back for that). Guess it's in "previous posts", I never looked.

cruiser54

Not saying I ever posted that info........

I need to keep a secret or two and I just gave away another one. Crud.

DIRTRIDER

Today i recovered all grounds on engine and made three big ground wires around the engine. I have tested all sensors again and everything was in correct measures. Then i turned off the IDLE STEP MOTOR jack when the rpm was about the 600-650 and left the engine work. What i see ? good rpms and no more shakings. The only one trouble is when the engine is cold after long parking time you have to keep your leg on a gas pedal. Tomorrow i am going to buy new idle motor... Time will show

cruiser54

Progress.

DIRTRIDER

Friday,yeah ! So i have some good news .I have bought non original Idle Stepper Motor (CROWN part number CR83503643 ) and everything is great now! Thank you guys for your replies and wish to you all a good weekend!

cruiser54

Glad to hear it. Enjoy your weekend also!!

DFlintstone

Great! (and I didn't think that was it!). (my u-tube audio didn't work, only had your tack). The IAC will stop wherever you unplug it. The "hunting" stopping with it unplugged was no surprise. It's a computer controlled vacuum leak you know.

Glad you got it! Check your MPG....

OK, I listened with audio. The cycleing time for mine was a few seconds longer than yours. If your new after marked IAC is dead, it would work just like your old one, unplugged. I don't mean to be a "wet blinket"........it just doesn't sit right . The IAC controls the air bypassing the throttle plate, with info from the puter" Seems your old one was going in and out trying to find the right spot. Anyway glad you got it.