Calling Renix Idle guys

[OverTheHillsATTW]

New question on the subject. I had two TPS sensors to test with. The first one I thought was bad because of 4,500rpm shift points. Now I threw in a different one. I went to read the volts and nothing..but it was 10 minutes after the ignition had been on the ON position. I put the old back on and same thing 4,500 SHIFT and stalling at every stop sign and turn. I put the 2nd one in and it shifts great..the idle even seems close to normal. I get out on the road and pedel to the floor and it's like turtle on my John Deere. I also had to do a TB swap because my butterfly was so off. I've cleaned the ground wires and bought a can of CRC electric cleaner and Grease. A very nice guy at Advance down the road also helped me out by giving me a whole book to borrow on Renix era engines and how they work. I'm just trying to figure out the loss in power. It had tons of power for a 19 year old engine before the shift points happened.

 

[89xj]

New question on the subject. I had two TPS sensors to test with. The first one I thought was bad because of 4,500rpm shift points. Now I threw in a different one. I went to read the volts and nothing..but it was 10 minutes after the ignition had been on the ON position. I put the old back on and same thing 4,500 SHIFT and stalling at every stop sign and turn. I put the 2nd one in and it shifts great..the idle even seems close to normal. I get out on the road and pedel to the floor and it's like turtle on my John Deere. I also had to do a TB swap because my butterfly was so off. I've cleaned the ground wires and bought a can of CRC electric cleaner and Grease. A very nice guy at Advance down the road also helped me out by giving me a whole book to borrow on Renix era engines and how they work. I'm just trying to figure out the loss in power. It had tons of power for a 19 year old engine before the shift points happened.

check to make sure the vacuum line to the MAP is connected at the side of the TB and at the MAP. i once plugged the vacuum line onto one of the studs/bolts coming off the MAP instead of the vacuum port. also test the MAP

 

[OverTheHillsATTW]

I was just checking over my vacuum lines and my PCV valve just flopped right out. The grommet has rotted to the inside(I fished her out). Could this have any effect on performance and idle?

 

[89xj]

I was just checking over my vacuum lines and my PCV valve just flopped right out. The grommet has rotted to the inside(I fished her out). Could this have any effect on performance and idle?

it could, fix the CCV lines and grommets and take for test drive.

there is no PCV valve on the 4.0

 

[Saudade]

What year is that from? My 89 Firewall connector is ALOT different. Its a two-piece connector that's located underneath the brake booster. Cleaning it was a real PIA. If I were to do it again, I wouldn't unless I had problems.

Mine's an 88. I had some weird elect problems as well one time. When I pulled the connector apart, I saw all sorts of corrosion, dirt and crusty grease in there. I spent over an hour cleaning it up and regreasing it. At least, mine was easy to get to.

 

[dizzymac]

check to make sure the vacuum line to the MAP is connected at the side of the TB and at the MAP. i once plugged the vacuum line onto one of the studs/bolts coming off the MAP instead of the vacuum port. also test the MAP

WHEW!!! I thought I was the only one that ever did that.

 

[8Mud]

New question on the subject. I had two TPS sensors to test with. The first one I thought was bad because of 4,500rpm shift points. Now I threw in a different one. I went to read the volts and nothing..but it was 10 minutes after the ignition had been on the ON position. I put the old back on and same thing 4,500 SHIFT and stalling at every stop sign and turn. I put the 2nd one in and it shifts great..the idle even seems close to normal. I get out on the road and pedel to the floor and it's like turtle on my John Deere. I also had to do a TB swap because my butterfly was so off. I've cleaned the ground wires and bought a can of CRC electric cleaner and Grease. A very nice guy at Advance down the road also helped me out by giving me a whole book to borrow on Renix era engines and how they work. I'm just trying to figure out the loss in power. It had tons of power for a 19 year old engine before the shift points happened.

With the auto tranny the TPS is actually two TPS's sandwiched together. They actually work just the opposite of each other, the TCU (tranny side four pole square connector) starts out at the supply voltage usually 4.8 or so and falls in voltage as the throttle is opened. The other half connected to the flat connector ECU (engine) side starts out low 0.8 volts ideally, then the voltage rises as the throttle is open. Two completely separate TPS's. They do end up grounding at the same spot, the dipstick holder and then through the Renix killer ground strap at the back of the head to the firewall and to battery ground.
When the ECU side of the TPS shorts internally from water or whatever, you get a high idle often in the neighborhood of 3000 RPM or so. When the ECU side of th TPS has a flat spot or poor contnuity you often get sluggish throttle response and even sometimes timing pop.
The MAP vacuum line being leaky or disconnected with cause a really poor running motor, hardly idles and will not rev very high. The plug for the MAP on the side of the TB is oval and has has two rubber plugs (one hollow for the vacuum and one solid) and can be put in upside down. One of the two holes in the side of the TB for the MAP vacuum rubber plug is a blind hole and you won't get any vacuum to the MAP if you reverse the plug.

 

[Harlee&Tahoe]

After adjusting my TPS to proper voltage I had crazy idle issues.
I never tried to drive it in that state.
Did you reset the computer? You will make it go through a re-learn stage.
With an auto Automatic Transmission
Set parking brake, start engine in "P" or "N" position.
Warm-up vehicle to normal operating temperature or until cooling fan cycles.

Allow vehicle to idle for one minute in "N" position.
Select"D" and allow engine to idle for one minute.

Accelerate at normal throttle position (20-50%) until vehicle
shifts into top gear.

Cruise at light to medium throttle.

Decelerate to a stop, allowing vehicle to downshift, and use
brakes normally.

Process may be repeated as necessary.
:cheers:

 

[Ecomike]

Sounds to me like both TPS sensors are bad, but each one has a different fault and thus a different symptom. There are many bad effects a bad TPS can have and they depend on where in the output signal the TPS has failed and on which side it failed for the AW4 tranny DUAL TPS. One of yours is really bad on the transmmision shift point side of the TPS, thus the very poor, very late shifting, high reving. The other is also bad on the transmission side but is causing very early shifting. I had the very early shifting problem for 3 years, thought at one point something might be wrong with the engine, but it turned out to be the TPS on the TCU side causing early shifting (like yours).

Here is how it works (in your case). If when rotating the TPS the TCU side actualy goes from 0% to 100% of expected signal strength (output voltage back to the TCU) in only 20% of the span, then that 20% of WOT signal acts like 100% WOT on the TCU side and locks the TCU-Transmission in the lower gear until about 4500 rpm, while the other side of the TPS operates the engine Air/Fuel and timing normally.

The other bad TPS is doing the opposite, it is making the TCU - Transmission think that 100% of WOT (Wide Open Throttle) is only 20% of the span, so the transmission is upshifting early at like 1,400 rpm even at WOT which kills the power since peak torque is at 2,400 to 3,000 rpm.

There are several other TPS failure versions that cause other problems like rapid shfting back and forth between 2 gears....surging engine rpms, low, high idles.....

New question on the subject. I had two TPS sensors to test with. The first one I thought was bad because of 4,500rpm shift points. Now I threw in a different one. I went to read the volts and nothing..but it was 10 minutes after the ignition had been on the ON position. I put the old back on and same thing 4,500 SHIFT and stalling at every stop sign and turn. I put the 2nd one in and it shifts great..the idle even seems close to normal. I get out on the road and pedel to the floor and it's like turtle on my John Deere. I also had to do a TB swap because my butterfly was so off. I've cleaned the ground wires and bought a can of CRC electric cleaner and Grease. A very nice guy at Advance down the road also helped me out by giving me a whole book to borrow on Renix era engines and how they work. I'm just trying to figure out the loss in power. It had tons of power for a 19 year old engine before the shift points happened.

 

[OverTheHillsATTW]

:yelclap: Thanks guys.

 

[Harlee&Tahoe]

Did you resolve issue?
What was it?

 

[OverTheHillsATTW]

I'm going on the basis I actually have a bad tps. I've cleaned every wire harness/sensor and greased everything. I cleaned my grounds and found no resistance in the wires or any splits or tares. I can adjust the TPS close to specs but one wont shift and the other shifts too low. I went to advanced after seeing them for $90+ online and picked one up for 55 bucks. I figure I know this one will be working and if I have problems with this im just going back to square one and going from there. I also replaced CCV valve and located a few vacuum leaks that are now fixed. My new TB seems to be closing properly aswell.

TPS #1 had high shift points/stalling problems and TPS #2 had very low shift points resulting in no power.
They were all pulled off old sitting TB's aswell.

It only seems to be getting better the more I clean and adjust. I appreciate all responses.

 

[OverTheHillsATTW]

Okay after riding around town today my Jeep started stalling at stop signs and every turn once again. I took it back home popped the hood and tried just looking for loose ends and more stuff to clean. My engine will now either start and immediatly die after a couple stumbles or rev to 3000+ RPMS. Rides fine while moving. The TPS is brand new. After I swapped that on it ran like a champ no stalls or anything. Now i've got this going on. :-(

 

[Ecomike]

Okay after riding around town today my Jeep started stalling at stop signs and every turn once again. I took it back home popped the hood and tried just looking for loose ends and more stuff to clean. My engine will now either start and immediatly die after a couple stumbles or rev to 3000+ RPMS. Rides fine while moving. The TPS is brand new. After I swapped that on it ran like a champ no stalls or anything. Now i've got this going on. :-(

Sounds like a sticking IAC or IAC wiring, issue. Check the throttle body plastic Vac line (with the dual rubber nipple on the TB end) that runs to the MAP sensor, make sure it did not pop loose at the TB.

The turn part just adds more load to the engine, so if it is dying at idle the turning is just letting it die easier, faster.

 

[OverTheHillsATTW]

Alot faster.
I've learned to kick it in N and restart it before traffic catches up.