garry

I replaced the idle IAC and TPS with brand new ones; and i still have a slight hesitation during acceleration.

It idles a little better but, still behaves as though it wants to cut off.

garry

i'm fresh out of ideas as to what is causing this problem; could it be my fuel pressure regulator.

Can anyone please verify what the exact fuel pressure should be; cause i installed a new IAC valve and TPS.

the engine runs a bit better but that stuborn intermitent idle during a cold start and normal driving speeds is still there. It's sounds as though the engine is been starved of fuel or the ignition timing is retarding to much.

84zmyfavorite

Non related, but Does your 87 have the Dana 44 rear axle?

garry

sure thing i've got a spicer 30-7AF inthe front and a Dana 44 at the rear it's a beast.

garry

I've got a new prob and it's coming from my tranny, i've an AW4 automatic tranny with [P-R-N-D-3-1]. it has recently stopped shifting when it is cold.

i've put in a new filter and a gasket fresh fluid repaired the oil cooler lines; adjusted the TPS from a reading of 0.4+ to 0.8 and the prob is still there. She idles much better now that i've adjusted the TPS that's the only good sign.

if i start her up and leave her to idle for approx. 10mins or so the tranny shifts ok other than that it won't. I've even placed some bottles of tranny fix and still nothing.

can anyone please give me some insight on what could be my prob.

garry

Hey guys I've finally sorted out the problem with my tranny i had a bad TPS ground wire. So I bypassed the original ground wire and grounded the tps elsewhere. I've since had no more tranny problems she's shifting like a baby now.

The only problem that I'm experiencing is right now is that I stall out when I crank her up on mornings. It seems that she only wants to idle whenever she warms up. I've removed my crankshaft position sensor, coolant temperature sensor and cleaned them up.

I've even pulled my ECU and cleaned the terminals thoroughly as a matter of fact I've cleaned all electrical connections in sight. But she still stalls out whenever the engine is cold. She runs pretty ok when she warms up. But there is still some hesitation and sputtering throughout driving.

Can anyone give me some insight into what my problem might be cause I'm fresh out of ideas.

cruiser54

Too bad I didn't post this earlier. One of the first things it recommends is checking the TPS ground. Sorry.RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently cleaned.
It's especially important that the edges of the throttle butterfly are free of any carbon build-up.
IMPORTANT NOTE: Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector
of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post.
If you see more than 1 ohm of resistance some modifications to the sensor ground harness will be
necessary. The harness repair must be performed before proceeding.
I can provide an instruction sheet for that if needed.
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body.
This manual transmission vehicle TPS provides data input to the ECU. The manual transmission
TPS has three wires in the connector and they're clearly embossed with the letters A,B, and C.
Wire "A" is positive.
Wire "B" is ground.
Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors..
Note the voltage reading--this is your REFERENCE voltage.
Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your
OUTPUT voltage.
Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For
example: 4.82 volts X .17=.82 volts. Adjust the TPS until you have achieved this percentage. If
you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION:
RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three-
wire connector, same as the manual transmission vehicles have, and it is tested the same as the
manual transmission equipped vehicles--FOR ENGINE MANAGEMENT RELATED ISSUES.
However, the automatic TPS also has a square four-wire connector clearly embossed with the letters
A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module.
Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your
REFERENCE voltage.
Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT
voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage.
For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage.
If you can't, replace the TPS and start over.
So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and
the other side feeds the TCU. If you have TRANSMISSION issues check the four-wire
connector side of the TPS. If you have ENGINE issues check the three-wire connector side of
the TPS.
For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is
stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.
Revised 11-28-2011

garry

Thanks a million for your response, actually I have adjusted the tps on my 87 wagoneer XJ with AW4 auto tranny to 4.0V output voltage previously I had it set to 4.2V

I was wondering if that reading is to high or reasonable giving that it is two clicks of the 3.98 reading that you suggest.

cruiser54

Don't use my figures. They're just examples. You have to calculate it off YOUR reference voltage.

And, I would also check the Engine side of the TPS while you're at it. As explained in the write-up, one side of the TPS can be good and the other side bad.

That being said, the TPS was grounded through the same circuit as MAP, IAT, CTS. Do you know how that circuit is grounded now?

Check it using the IMPORTANT NOTE in the beginning of the write-up.

cruiser54

And since you have an 87, read this. Super important and a cause of numerous driveability problems. The reasons why are stated in the write-up.

Renix Jeep C101 Connector Refreshing
　
The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.
　
　
Revised 11-29-2011

garry

Thanks a million once more i certainly have a great deal of work ahead to get this connector sorted out. Currently my MAP, IAT, CTS, TPS sensor are grounded stock from the factory excepting the TCU side of the TPS which i modified and grounded it together with the fan relay on the left fender panel cause i was having transmission shifting issues.

I have been tempted in the past go into that C101 connector and clean it, but wasn't sure how to go about it.

I'll pull apart that C101 connector in the next few days and give a feedback on my results.

thanks again.

garry

So I have cleaned my C101 connector and the problem with my idle is still there. She just doesn't want to idle when she's cold.

Guess I'm back to square one, however I did some more research and I'm beginning to think could it be my o2 sensor that's messing up.

cruiser54

O2 sensor isn't into play when first started cold. Did you ever do the sensor ground test as described in the TPS procedures undere Important Note?

garry

Oh, I forgot to mention that I was able to rerun my TPS ground as it should be. So at least I can say that I have achieve one thing out of cleaning that C101 connector.

cruiser54

That means you sensor ground circuit has TESTED okay with a meter? There are three other sensors on that circuit.