Renix issue?

[5-90]

Thanks for the input, Haven't done the egr delete per se, I have cut and plugged the vacuum line between the transducer and the valve. Preventing the valve from opening except maybe with a huge amount of exhaust pressure. Not sure if thats correct but thats what I've done. Did notice that when you give it sudden throttle there is a huge hesitation no matter the temp.

Pulling the vacuum line effectively blocks off the EGR - exhaust pressure building up behind it tends to pull the pintle shut, not push it open.

Rich sounds like a vacuum leak or some other issue. And, if you've been running rich enough long enough, you're going to be looking at the porous ceramic in the HEGO sensor tip being plugged up anyhow (which will cause it to "fail over" into Open Loop mode anyhow - making it run rich.)

I don't want you to throw parts at it either, but I'd say to do the following:

Disconnect the cat (driveway)
Remove the plugs and brush them off (a dry toothbrush should take care of carbon deposits readily.)
Reinstall the plugs.
Run Seafoam (or cleaner of choice - even water spray) down the intake and blow out any loose carbon.)
Recheck plugs - they should be cleaner this time.
Replace HEGO (you didn't do it earlier because you're going to be blowing around loose carbon.)
Reconnect cat.
Return to normal service for one week, and recheck plugs. They should, hopefully, be cleaner this time. Also take the week to re-evaluate fuel economy, and compare it to what you're getting now (it should, hopefully, be better.)

Leave the EGR disconnected from the vacuum source for the moment - no sense in adding additioinal carbon to the intake stream to screw up what you're doing. You can always reconnect the wretched thing later (principally to remain in compliance with EPA regs - damned thing does more harm than good on our engines anyhow...)

The RENIX system doesn't use a standard HEGO sensor, but a Bosch repalcement should still be well under $100 at the local.

 

[jujuscisyn]

Thanks again folks, I feel like a pita. But I think its time to drop back and punt, take a few minutes to reevaluate. Just as you suggest. Here's the plan. Gonna try to get the cat off (wish me luck, I've got holy cow corrosion back there). Tail pipe fell off last week anyway. After looking at the egr, I cut the vacuum between the transducer and the valve. Thinking this needs to be cut before the transducer. Anyway I'm gonna start with vacuum just cause it really seems vacuum related. Gonna replace the o2 sensor Just so I can eliminate the thing diagnostically. I replaced the plugs yesterday, not knowing any different I had platinums in it, went back to the good ol copper champs.(geez, I love ). Anyway starting with the top end vacuum and o2. Thanks again guys, don't give up on me, I'll get it. Have to, its a vendetta now. I'll keep you posted.

 

[PacificEd]

HEGO....what is this?

 

[Shorty]

HEGO....what is this?

Heated Exhaust Gas Oxygen sensor

 

[Shorty]

Thanks again folks, I feel like a pita. But I think its time to drop back and punt, take a few minutes to reevaluate. Just as you suggest. Here's the plan. Gonna try to get the cat off (wish me luck, I've got holy cow corrosion back there). Tail pipe fell off last week anyway. After looking at the egr, I cut the vacuum between the transducer and the valve. Thinking this needs to be cut before the transducer. Anyway I'm gonna start with vacuum just cause it really seems vacuum related. Gonna replace the o2 sensor Just so I can eliminate the thing diagnostically. I replaced the plugs yesterday, not knowing any different I had platinums in it, went back to the good ol copper champs.(geez, I love ). Anyway starting with the top end vacuum and o2. Thanks again guys, don't give up on me, I'll get it. Have to, its a vendetta now. I'll keep you posted.

don't worry about where you block the vacuum-- put in the block-off plate. You could have a bunch of gunk in the pintle/ seat which will stop it from closing and sealing off the exhaust either way. This will show itself as a "vacuum leak" in it's symptoms since you're leaning the mixture (unregulated air entering the combustion chamber) and cause the HEGO sensor to tell the ECU to swing rich to compensate. It is rather common for the EGR to stick slightly open when hot, but slowly close as it cools.

 

[Ecomike]

5-90, are you still using the Bosch platinum single ground electrode plugs?

 

[Ecomike]

Thanks again folks, I feel like a pita. But I think its time to drop back and punt, take a few minutes to reevaluate. Just as you suggest. Here's the plan. Gonna try to get the cat off (wish me luck, I've got holy cow corrosion back there). Tail pipe fell off last week anyway. After looking at the egr, I cut the vacuum between the transducer and the valve. Thinking this needs to be cut before the transducer. Anyway I'm gonna start with vacuum just cause it really seems vacuum related. Gonna replace the o2 sensor Just so I can eliminate the thing diagnostically. I replaced the plugs yesterday, not knowing any different I had platinums in it, went back to the good ol copper champs.(geez, I love ). Anyway starting with the top end vacuum and o2. Thanks again guys, don't give up on me, I'll get it. Have to, its a vendetta now. I'll keep you posted.

Have you tried testing the O2 sensor with an analog volt meter yet, before replacing it? If not see the RenX files thread for how to test it.

 

[jujuscisyn]

Haven't tested the o2 with analog yet, because...ha ha this is funny, while checking the tps I hooked up the cheapy analog to the sensor, to check for flat spots, with the meter still on the ohm scale. Fried resistor inside. Bonehead maneuver, so I need a new one. That fuel leak at the rail/supply is highly suspect, gotta go get that damn kit somewhere, Chrysler just shut down the local dealership, guess they are worried about money. If they had just waited I could've kept them in business with my xj alone. Ha ha. Gonna call napa. Thanks for the help guys and I'm gonna test o2 as soon as I get the meter. You are talking about the test where you watch the needle bounce around rapidly, right? I love my Jeep!!

 

[Ecomike]

Haven't tested the o2 with analog yet, because...ha ha this is funny, while checking the tps I hooked up the cheapy analog to the sensor, to check for flat spots, with the meter still on the ohm scale. Fried resistor inside. Bonehead maneuver, so I need a new one. That fuel leak at the rail/supply is highly suspect, gotta go get that damn kit somewhere, Chrysler just shut down the local dealership, guess they are worried about money. If they had just waited I could've kept them in business with my xj alone. Ha ha. Gonna call napa. Thanks for the help guys and I'm gonna test o2 as soon as I get the meter. You are talking about the test where you watch the needle bounce around rapidly, right? I love my Jeep!!

All the local parts houses have the o'rings for the fuel line and the injectors.

Have you checked the meter for a replaceable blown fuse?

O2 sensor? Answer is, YES!

 

[jujuscisyn]

How did you rule out the tps? Did you check for noisy spots when it is hot using the analog meter method?

Have you considered or tested the O2 sensor?

Have you checked for I-E manifold leaks, loose bolts?

Considering the multimeter fiasco I haven't truly ruled out the TPS. I fully intend on checking it again. I've got a ground ran from the sensor side of connector right to the battery, now the voltage on ground is on the mV side way less than .1 compared to .8 where it was. I have it adjusted to 82.9 % pretty close to the 83% per the renix fuel injection manual. gonna try to get an egr delete fashioned up. I currently don't live in a sniffer state but got a bad feeling its coming. Gonna try a (cough)copy(cough)cat as well. Gotta find a test pipe!

 

[jujuscisyn]

All the local parts houses have the o'rings for the fuel line and the injectors.

Have you checked the meter for a replaceable blown fuse?

O2 sensor? Answer is, YES!

The one leaking is the quick disconnect at the rear of the fuel rail. I haven't found a source locally yet. Napa doesn't have it, My only other options are AZ and OR gotta check these two. Other than that, it will be FI rated hose and clamps. I know that 5-90 is working on these but in the interim gotta come up with something. Again Thanks a Million

 

[Ecomike]

It is frequently in the HELP parts section as well.

 

[kaptinkaveman]

In my 89 the fuel pressure regulator on the fuel rail had an internal leak. It was letting fuel into the vac line. Ran fine wile moving but no idle, poor economy, and smoke. Replaced it and it runs like new!
:clap:

 

[jujuscisyn]

Here is what's going on. EGR deleted. Who ever put those torx heads in that spot should really be torn into itty bitty pieces. So while the airbox was out and I had access, I decided to check the manifold bolts. Guess what? go on guess I'll wait. I checked the top ones before and they were even torqued to specs couldn't really get to the lower ones. They weren't falling out by any means and probably not leaking cool but I bet if you add some heat, voila. I'm not saying this is the trouble, cause I've just got the fuel rail and the and heat shield out to retorque these things they look like a pita to get to.
As far as the seal kit for the supply line being in the help section, are they on that plastic installer thingy or am I just looking for o rings of appropriate size? I ask because the plastic spacer came out with the thing and is now rolling around in the yard somewhere. I didn't know if I was going to be able to directly replace these or if I am going to have to fab something up. Anyway, like I said, I am starting from the top. Resolving Vacuum, then I'll be moving on to electrical and sensors, then I've got to get the exhaust taken care of. I don't get to work on it like I want to but I'm getting there. You guys have been great, thanks for all the help. I'll keep you posted.

 

[jujuscisyn]

In my 89 the fuel pressure regulator on the fuel rail had an internal leak. It was letting fuel into the vac line. Ran fine wile moving but no idle, poor economy, and smoke. Replaced it and it runs like new!
:clap:

I'll definately be looking into the fpr after I get the known mechanicals taken care of. Thanks

 

[Ecomike]

I think the retaining clip is Dorman #800-005, in or near the help section, GM/Chrysler 5/16" retaining clip, pack of 5, and the o'ring is Dorman #800-013, which has 5/16" and 3/8" o'rings, 2 ea.

 

[jujuscisyn]

Gotta love those little discoveries. Ok went to retorque manifolds this morning found a missing bolt... ah ha theres my leak. So I scrounge around looking for the appropriate replacement only to find its not a bolt. Yep, PO snapped the rear most exhaust manifold stud. Had to look that one up, it is in fact supposed to be a stud. Its easily an 1/8 of an inch inside the head. I'll have to pull the head to get to it and extract it. Not sure how much its leaking but went ahead and retorqued the rest. Went around and checked the vacuum and all looks good but It's not starting well and still has that damned stumble after its warm. Still no matter the temp when you go from under 1 grand and give it sudden throttle, theres hesitation and a great sucking sound from the airbox then it pops and bangs and goes. When you ease into it, it does better.
I went around with WD-40(don't have a propane torch at the moment) and sprayed around the usual suspects looking for vacuum leaks and got nothing. Pulled individual injector connectors and got misses on each one pulled. Pulled the vacuum off the FPR and didn't see any fuel. I'll have to get my hands on the fuel pressure gauge again and check that again. Right now its a mystery. I can't recall that I've ever had this much trouble diagnosing car trouble. Not gonna be able to do anything with it till Wednesday or so, it broke me, no money right now. Gotta get a new analog meter (yep fried resistor wish it were a fuse) so I can check the o2 and TPS. See if I can borrow the neighbors FP gauge. As always, Thanks for the info and help.

 

[1990JEEPXJ]

im having the same problem. i also found loose manifold bolts, still stumbles and dies after idling for a bit and stumbles off idle.

 

[jujuscisyn]

Yep, that's the gremlin. Same here. These guys on here have put up some really good ideas, if you haven't already and have the time, I'd give it a read. Just read what those guys posted cause I'm a hack at diagnostics. Hope you get it figured out, I'm leaning towards the o2 or FPR right now. My plugs say rich, lots of carbon. How do yours look?

 

[1990JEEPXJ]

i changed the plugs and wires today. the plugs looked good. normal tan color. but i need to change the distributor cap which had a terminal that was incredibly blue and corroded. the rotor wasnt super clean either. but i also think it could be my MAP sensor. the vacuum line is all hacked to it as well. but i will check the fuel pressure when i get the chance