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How does you renix cold idle?

D

DaveXJCO

NAXJA Forum User
Location
Durango, CO
Just curious how most of you remix owners reps run hen started in the morning. Mine starts and idles high for a moment, then drops down to around 750-800. Does that for ten seconds or a little longer. Then idles lower for about the same time. It seems to switch between a warm idle and a low idle until warm. Once warm. It idles normally. I don't rwmeber it ever really going into to cold high idle until warm since I've owner it. When I start it every time it idles high for a couple of seconds like normal and then drops to a normal idle. But when cold it can't decide.
 
Throttle body is spotless. Cleaned it last week. It wasn't even dirty. The pintle seat was very clean. New tps a couple of months ago. I set it correctly then and rechecked it last week. I'm wondering if my IAC is just dead in place.
 
DaveXJCO said:
Just curious how most of you remix owners reps run hen started in the morning. Mine starts and idles high for a moment, then drops down to around 750-800. Does that for ten seconds or a little longer. Then idles lower for about the same time. It seems to switch between a warm idle and a low idle until warm. Once warm. It idles normally. I don't rwmeber it ever really going into to cold high idle until warm since I've owner it. When I start it every time it idles high for a couple of seconds like normal and then drops to a normal idle. But when cold it can't decide.
Click to expand...
Startup flare to about 1000 rpm and settling in at ~750. Perfect operation for a renix.
 
Sounds pretty normal, but check for vacuum leaks anyway.
 
I just have never heard my keep idle high beside the first couple of seconds of start up warm or cold. But I though that it should high cold idle for a couple of minutes until its warmed up. It starts, idles high for a few seconds like normal, then drops down to a warmed up idle when still cold. Maybe that's how the renix system works. No high idle for warm up.
 
I have owed several Renix XJ's and they all start and idle normal whether hot or cold. Whenever I experienced issues with it revving high on initial start up the issue has always been resolved by either cleaning the IAC or replacing it.
 
It doesn't idle high at all. It just idles at 750 after the initial fire up high idle that takes place for about 3 second . After that, 750 rpms and that's it. When its fully warmed up. The sane. Why didn't they add a cold start high idle until the ect says its warm and to drop the idle?
 
Sounds about right to me... that's basically how mine idles, and it's completely redone with all-new sensors, gaskets, pressure-washed intake manifold, bored TB, 746 injectors, completed almost all the Cruiser54 tips, etc etc etc. It's a little funky the first few minutes until it heats up and/or the ECU does it's open/closed loop black magic. If it's idling roughly within spec on the ~25 year old RPM gauge I call it good. When I start getting nutty about fine-tuning stuff like that I try to remember the damn thing isn't a 1/4mile dragstrip hotrod, it's a survivor renault/bendix Jeep. Last weekend it took me well past the spot where a JK Rubicon an hour in front of me turned around.

If it's running, passes emissions and doesn't knock/tick/rattle too nastily I will happily thrash it towards Valhalla, Shiny and Chrome!
 
On mine, I turn the key, wait for the fuel pump to prime (2-3 seconds) and then start it. RPMs flare to +/- 1500 for 2-3 seconds and then settle down to 750.
 
If it starts real high then drops, the ASD "automatic shutdown" relay could be flakey. When you turn off the engine, it keeps the power to the computer for a few seconds to allow it to set the IAC for startup conditions. If it shuts down too soon, the IAC is in the wrong place and it takes a few seconds for the computer to compensate and adjust the idle down.
 
old_man said:
If it starts real high then drops, the ASD "automatic shutdown" relay could be flakey. When you turn off the engine, it keeps the power to the computer for a few seconds to allow it to set the IAC for startup conditions. If it shuts down too soon, the IAC is in the wrong place and it takes a few seconds for the computer to compensate and adjust the idle down.
Click to expand...
Actually, its called the latch relay.
 
Helped a friend get a 90 that was destined for the junkyard back on the road.

All new sensors, TPS indexed, bypassed all unnecessary vacuum lines and replaced the necessary ones. Aside from the typical Renix excessive crank, it shoots up to about 1000 then almost immediately down to 750 or so. Runs nice and smooth, though.
 
When mine gets into a funky idle it's always been vac lines, particularly the one from the MAP to the TB.

Also, check your manifold bolts. I have one in the front that likes to back out a bit, creates a little air leak when cold but closes off when things warm up.

Kind of funny, sometimes I can actually "adjust" the idol speed by loosening and tightening that one manifold bolt. (I think the next one down is broken off, so I probably get more flexing)
 
old_man said:
If it starts real high then drops, the ASD "automatic shutdown" relay could be flakey. When you turn off the engine, it keeps the power to the computer for a few seconds to allow it to set the IAC for startup conditions. If it shuts down too soon, the IAC is in the wrong place and it takes a few seconds for the computer to compensate and adjust the idle down.
Click to expand...

Good to know. Guess I'll replace that relay. Where is it located?
 
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