Haha yeah I have removed the hose off the tps, I just did that to see if it ran better with a higher voltage.

I'll look into cleaning that iac and connector really good

What should I use to clean i intake air temp sensor? Don't want to mess it up
Since I cannot find a new one anywhere

 

For the idle air control on the TB, I'd spray in that connector good with contact cleaner, work the plug on and off a few times, repeat a few times.
(the IAC takes the place of the idle speed adjustment screw of old)

To clean your IAT on the intake manifold you can use about anything I think. I think I used a toothbrush and starting fluid. I bet you will find it pretty gummy when you get it out, but it might be a pretty minor player in the big picture. (maybe it matters more in extreme cold)

 

Okay thanks

Here a little more bit of info
The old motor had a low idle like this too, but lacked the almost stalling part I have somehow got. So I think the issue may be laying elsewhere?
The iac and tps was used about 2 months on th old motor before I decided to just buy a new block to put in. When I got the new motor put in i replaced every sensor on this motor except aic,tps and iat sensor

Since then I have replaiced everything but the fuel pump (which wines a bit) and iat sensor but I may be forgetting a few things tho.

Would a fuel pump sucking air cause this issue?

 

I don't want to "derail" the thread, mainly just wanted to share my hassles with the Idle Air connector.

The pump is submersed in fuel and pressurizes the lines. (and fuel flows in a loop up to the regulator at the front of the rail, then back)

Not seeing how air could get, or stay in there.

 

Carb cleaner or brake cleaner on the IAT.

 

well another evening working on this thing and its getting a little old after working a 10 hr shift haha

So first i cleaned the iac and it was still clean from when i cleaned the tb last time i cleaned it a few months ago

Next i cleaned every connector and relay i could find in the engine bay with a electrical cleaner and a tooth brush making sure to brush both male and female side. i still dont know what those two stray wires are for that are in the harness going to the ecu either (purple and white)(white and black)

Then i pulled the iat and it was nasty! sprayed it good with some carb cleaner and its good and clean now

checked my voltage to all my sensors and they were all 5V, and resistance through the iat and it said 1200-1300 ohms so that seems ok, my intake manifold was reading around 35C with my temp gun

still no change in idle

BUT i do have some good news i unplugged my cts and iat sensors to raise my idle up around 700 and then did a vacuum test and it pulled a nice 14in with the slight rise and fall with slight rpm oscillation. so you were right cruiser, i think my timing is good

putting the scanner on the other day kinda confirmed a lot of the sensors are working properly such as the cts, iat, O2, Knock, map,tps because there values were pretty close but i have no idea what my short term and long term fuel trim should be? i also have not used a diagnostic tool very much.

so i dont know what to test or look for now any pointers would be great??

 

My Tip 5?

 

i have cut out the bad factory ground crimps and added in a extra ground to my firewall and 4ga on the dipstick to frame all connections are shiny. My resistance is about 0.2 to 0.3ohms, this doesn't change when i wiggle the harness

Tonight i was trying to think back to when i first bought this jeep and how it ran. I remember i was chasing the long crank time (2-3 sec) because i am uste to my new vehicle, need less to say i came to learn that its kinda just how the renix is, but in doing this i cleaned the TB and replaced the iac because i thought it was the problem. I think that is where my low idle started shortly after i replaced the tps because i started chasing this low idle issue.

Is it possible i have a bad new iac and its not adjusting properly, is there anyway to test it?

 

Just to be double clear, my point was I to cleaned my IAC a number of times. Then eventually figured out it was the CONNECTOR, not the IAC it's self that was causing my idle problems.

Booger socket faces up, so coolant or water could sit in there and cause a problem with the connections. A signal from the ECU to the IAC motor to pull the pintle out a tad to up the idle would need to get through there.

 

I cleaned the connector well lastnight, did you just clean it or replaice it?

 

Did you ADJUST the new TPS on the engine side?

 

yep sitting at .82v

so i have been doing some reading and decided not to rely on my scan test for my o2 sensor

i did these tests at operating temp and this o2 is about 2 weeks old (Bosch)

at idle it tested at 0.12 volts with no fluctuation and 14 volts from the heater relay power

when reving it up and holding 2500-3000 rpm the fluctuation is from 1-4 volts but the 12volt power from the relay doesn't seem to turn off?

 

Should be .1 to 4.9 volts rapidly switching. Don't worry about the 12-14 volt power supply to the heating element.

I hate bosch O2 sensors.

 

yeah i think i will be picking up a ntk tomorrow, and taking this one back to get my money back

 

I would. Keep us in the loop. No pun intended......