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Renix low idle and stalls

deepstage69

NAXJA Forum User
Location
Kingsport, Tn
Ive got a 90 cherokee 4.0 and aw4, ive swapped into a 90 wrangler. The problem is that it runs well, except for idleing. On cold starts, it starts doesnt idle high but for a sec then idle slows way down and fluctuates up and down and eventually stalls out. After its warm, driving and come to a stop it idles down and eventually stalls.

Ive already changed Map, Tps , Iac, O2 sensors (new) and swapped know working Mat and Coolant sensor (used)

Thanks
 
My 96 was doing the same thing and I cleaned out the Throttle Body. Just remove the air cleaner hose and spray carb cleaner in there and use a tooth brush or other soft bristle brush to clean the walls of the Throttle Body. You will have to crank it a little before it will start. If that doesn't work, replace your fuel filter.
 
What is your reference voltage at the TPS? What did you adjust the output voltage to?

When cleaning the throttle body, make sure you use a "TB Safe" cleaner.

When you replaced the IAC did you clean the passages?
 
TPS input is 4.66v output is 3.83v.

Cleaned with TB safe cleaner, and yes I cleaned the IAC passage as well.

A tiny bit short of .83 percent of reference, adjust it up to 3.87 (couldn't hurt).

Have you checked the throttle plate initial position? Remove the intake tube from the TB. There is a 5/32 allen screw that keeps the steel throttle plate from slamming fully closed against the alloy TB. Back the allen screw out until if no longer effects the throttle plate, then turn it back in while observing the throttle plate for movement--at the first sign of movement STOP. Put things back together. Note: do this BEFORE you adjust the TPS.

Just for grins and giggles renew all of the grounds. Do you still have the grounds at the dipstick? Back of head to firewall? Make sure you take the surfaces down to bare metal and treat them with an anti-corrosion material--any hardware/paint store--and make sure they are TIGHT connections. Renix engine management is very fussy about its grounds.

Ok, one last thing--how much have you been able to run/drive this since the swap? If not much, then you can't rely on the exhaust condition for any info. You can, however, pull the plugs and check their condition. What I want to know is if the engine is running rich--black fluffy deposits on the plugs.

Last and most likely the least suspect--what thermostat are you running?
 
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