DFlintstone

Hey WoW! I'm envious...you have a real Fluke meter. (It's a fluke mine works at all). And funny that....just under 2 ohm's out of spec. In any case go with the AC test, I believe that is the actual signal the ECU depends on to...well, be a control unit!

DFlintstone

The three 02 wires WERE in the harness in my pic, and one of them grounding was the reason mine sputtered at mid throttle. (but would go floor-boarded). I should pull my tape and look to see which it was..the knock sensor and CTS are also there.

Make sure the key is off while doing ground resistance checks..I got 6 ohms on my 02 heater. You can check the 02 ground, 12V heater power, (from the front of 4 relays)(pic in my Sig), and it's 5V ECU feed Easy. HEY NOW. DO check that 5V from the ECU, on the harness side, unplugged. The orange heater is on one end should have 12. Ground in the middle should be an OHM'-sh to battery neg, If there were Not 5 from the ECU on the other end, that might be grounding, thus sending goofy info to the ECU. The Titania 02 sensor in our 87 to 90 Renix jeeps is way different than the later. It's a variable resistor! (that wire grounding would be not good). To check that pulsing 2-1/2 volts "back probing" with it plugged in, I ran one small strand of copper from inside the connection to my clip. I don't think I bent it, but normal would to back probe with a pin shoved in, alongside the wire. Even a paperclip. Your digital may, or may not work there for that. I'd assume you would get allot of resistance checking the unplugged ECU pin on the 02 sensor, to ground. I never checked that I remember, but my stone-dead 02 would not pull down that 5 volts at all.

When you check the 5v feed, on the unplugged 02 plug, giggle the wires from there to the injector harness, then the above main harness as well. See that the voltage is steady.

And fix the CPS!

anticreep

You can't go wrong with fluke.

Right now everything I have tested have turned up good. Still have to test the knock sensor.

It has a new fuel filter, TPS, IAC cleaned, and New MAP sensor.
How do I test the ECU to sed if it's going bad or week. If it can event be tested.
And that tester if u look on the bottom of the screen under the numbers there a bunch of lol bars if the power was flickering on and off real fast it would show up on those bars like and analog meter.
I thank u fellers so much for all your help hopefully here soon we get it whooped.

DFlintstone

The rare and elusive DRB-II, or the Snap-On 2500 (With the correct card, I suppose) are I believe the only scanners that will work. Even then I don't know about testing the ECU it's self. The Renix ECU is about bulletproof I gather. I even saw something about "aviation grade". Don't know about that.

I'd be thinking a wire or sensor, (or two). In your shoes I'd handle that CPS, the sensor ground circuit, then just check that 5v feed to the 02 sensor. Take it from there. It should run fine with the 02 unplugged. Btw, it will also run fine with the wires to the distributor (cam sensor), unplugged.

anticreep

I sure am trying to get her fix. Like I said before I have testes just about all the sensors all that thing.

I'm getting 5V to the o2 sensor. Today I took it for a drive and it was back firing and it sounded like it was coming from the engine compartment. I red something like the manifold like t crack on these jeeps. I'm wondering now if it's cracked.
What u mean sensor ground circuit. I tested the CPS and its all good.

cruiser54

First off, knock sensor will NOT cause any driveability issues.

If sensors test good, perhaps the ground circuit which 4 critical sensors share could be the culprit.

Click on the link in my signature below and do posts 1, 3, 4, and 5 before piddling around with anything else.

anticreep

Thanks cruiser54. Just one question before I try them how do I test the sensors grounds.

I see now I should of kept reading. That's a great write up cruiser54. I'll be out there do I g all of this today.

kjc

In your original post, you stated it doesn't downshift unless you floor it? I'd check/adjust your TV cable. It should be downshifting way before WOT. Just my $0.02

cruiser54

Post 5 in my tips.

cruiser54

TV cable doesn't control downshifting. Just transmission line pressure.

anticreep

I found 89% of the problem. It's just about fixed. It's still a lil love on power and has a lil backfire while in first gear. I just cleaned all the grounds and the wires that was messed up I taped and then heat scrinked over the tape. The main grounds coming from the ECU had a frayed wire. I'm going to replace all the power and grounds and fix the ground from the ECU.

anticreep

Here's another picture.

anticreep

The main grounds coming from the ECU.

cruiser54

Yep. I'm not surprised.

Now you know why I get borderline obnoxious with folks about dong that stuff FIRST.

You are the new poster child for the Renix Tips.

anticreep

Yeah thanks for all the help. Here soon I'm going to buy that ground and power wire kit u have a link for on that thread u wrote up. Btw that's some awesome info.

In first gear sometimes in second it has a bit of a stall and a backfire when giving it gas around 1/4 to 1/2 throttle. Could that be fuel troubles.