aroundincircles

Ok, I'm at a total loss on my 89 Wagoneer. So I'm doing a thing. I posted a video. go watch it, post a suggestion in the comments. I'll then do your suggestion, and if it fixes my issue I'll give you $500. Easy. I created a playlist here:
https://www.youtube.com/playlist?lis...qwmvrUzH8GhImk

Only Top level comments will count, and if you ask clarifying questions, I'll wait till I get a few and then try to answer several in one video.

Any comments on this thread are appreciated, but I'll only be following recommendations from youtube, that way I can more easily keep track of who and what (and when so if two people suggest the same thing I will know who suggested it first), and post video replies. It was at the shop for two months, and they couldn't figure it out... can the collective?

Any videos I do I'll add to that playlist, so if you want to follow, bookmark it.

MaskedMallard

I don't do YouTube, for comments.
- try pulling your rubber air intake off, at the throttle body to verify you don't have an obstructed intake & you have proper operation of the throttle body. Can you verify the throttle body will go WOT?
- containment fuel?
- introduce another form of fuel (carburetor spray), just to verify its not a fuel problem. I'd introduce this directly into the throttle body. Be sure to ask the parts guys what the most flammable carburetor spray they have & buy that.
- what spark plug & gap are you using?
- you said you did a lift? Did you crush the fuel line while lifting the Jeep?
- do you have a sparkplug gap tester? You remove a spark plug wire from the spark plug, install the gap tester, ground out the gap tester on the engine block & see how far the gap will jump.
- any check engine light codes?
- did you do any previous engine work, where you might have left a rag(s) in the intake / exhaust?
- verify timing, with a timing light?
- how's your grounding in the vehicle? Clean mounting points? On my old renix, I'd bought a large grounding strap, drilled out one side, so my oxygen sensor would would fit into the new augered out hole & bolted / screwed the oxygen sensor back down. I don't remember where I connected the other end, other then to most likely the body / frame.

Dave51

I didn't see where you listed the compression numbers. Timing might be a little high, perhaps because of the high idle. What does the emission sticker state for that? ECU should have compensated for that anyway. Pull the valve cover check for worn cam and lifters. Is the O2 heater sensor circuit working (low hanging fruit)?

Leaking EGR (more low hanging fruit).

robsjeep

https://www.ebay.com/p/14035406014?u...5581edfff88cbd

Consider getting a SnapOn MT2500 scan tool such as linked above. This will help diagnose Renix problems. I bought one and it finally helped me find the issues that vexed my renix 1990 XJ.

Dave51

Borrow HomerLV's smoke machine to find the (any?) vacuum leaks.

Dave51

Does the SnapOn offer any more functions than his R.E.M. device?

cruiser54

Don't think so. Maybe even less.

awg

Dont forget to keep us updated

On another forum, one member was having problems with his engine build, and offered to fly another member who was an expert mechanic, interstate,
put him up at a hotel, cant remember whether they did a pay deal as well, but the guy fixed it for him in one day

He was happy, $50k car though

Utah XJ

Ok it seems like vacuum to me too. In your video you show 16 to 1 fuel ratio which is lean. Since you replaced all lines you need to see what runs on vacuum. Like brake booster, heater controls, etc.

doublechaz

I doubt OP will be back here to read any of this based on his statements here and in the video.

Seems like an attempt to drive revenue through his youtube channel.

Dave51

Clogged fuel rail distal to the pressure monitoring port.

Dave51

But not occluding the outlet:

dave1123

Did anybody but me notice the fuel pressure drop to about 2 psi when he shut it off? Shouldn't it be holding pressure? It seems to be breaking up when he revs it up as well.

Yeah, stick OE injectors in it and see how it runs. You also need a better diagnostic tool.

aroundincircles

I'm back, sorry, I'm taking any and all advice here, my wife has been pushing for me to finish a home project, and all of my spare time has been spent on that, I've spent all afternoon painting, and getting ready to lay carpet.



I honestly and truly appreciate all the help. I'm not some fly by night member, I've been on the forum since 2014 with my first 1989 XJ Cherokee Pioneer:



Yeah, my fuel pressure drops after I shut off and If I let it sit for a while it takes a while to start. so the check valve is bad, but I don't think that is my issue since it maintains fuel pressure while running.

The shop it was at swapped in injectors from a running jeep, and it had no effect on the issue. so I'm 99.9% sure it's not the injectors.

as far as driving traffic to my youtube channel.... If I make any money off the video, I make <$1/1000 views. I just keep getting asked the same questions over and over, and giving the same answers over and over, and if I'm going to give somebody $500, I need SOME way to make it fair, or at least traceable as to who recommended something first as people are recommending the same things over and over. it's just me trying to simplify my **** poor attempt at trying to fix my jeep.

doublechaz

Excellent! I was wrong.

I'm going to watch the video again and refresh my thoughts on it. Back in a bit...

edit:

Vacuum leaks tend to screw things up *less* as you give it throttle so I don't think that is your main problem as your problem gets worse with more throttle.

We should be able to ignore the fuel pressure bleed down until after the breaking up is solved. Fuel pressure was correct during run and only showed a fault just after shutdown.

It's pretty hard to say since I didn't see any convincing evidence that it was really warmed up enough for normal operation.

We should be able to rule out a bad injector with what you've already done, but we can't rule out an injector not getting a squirt command. Noid each injector to rule this out. One injector not firing could give you a false lean since all the oxygen in that jug would go right to the exhaust and O2 sensor. I don't think this is it since it sounds even at idle.

If it was warmed up then there is a big problem with your AFR. The O2 stayed pinned, the AFR was pinned lean, and it was staying in open loop so your trims aren't active. On that topic we have to know if it is a true lean or a false lean. Causes for true lean at idle are vacuum leak in MAF systems or stuck IAC in MAP systems, low fuel pressure, obstructed fuel flow, false lean would be O2 sensor or wire problems or air getting into the exhaust.

Mine isn't running right now, so I can't be sure, but it seemed like your injector on time was high for idle. If someone else can confirm that I say it's a false lean. You can also try to check smell and color of your exhaust. If it is sooty and smells a bit like gas you can move towards a false lean. In that case do the electronic tests to verify O2 operation. We did just have a member with big troubles because the new O2 they got was not correct for a Renix. You can listen around the exhaust ports in the head for a tapping sound of exhaust puffing out. This can let air into the exhaust between taps making the O2 read high oxygen false lean.

But the big thing I would chase is that it sounds like 5/1 when you rev it. It is breaking up pretty bad. That could be from a true lean that affects one cylinder more than others. It could be from a pumping problem or compression problem in one cylinder. It could be from timing being out and one cylinder is more sensitive to it than others. Easy first check is to disable fuel and crank it for several seconds. If it sounds like 5/1 during cranking then it would be compression or pumping. Then move to a compression test. If that is even maybe pull the valve cover and verify no broken springs, collapsed lifters, equal movement of the push rods. There isn't a possibility that something got sucked into the intake and is partly blocking one intake runner? I doubt it as I don't think that would hold your RPMs down like you are seeing so don't use a scope to examine the runners until way later in this game.

If the above items check out then the labored sound when revving that makes so many people say your exhaust is plugged makes me think that you have way too much timing in it and it is fighting itself. If I understand Renix correctly the 14 degrees your REM II shows can be a lie if things are out of alignment. Go to cruiser54.com and follow tip 7 and 13 to be sure the timing is actually what the computer thinks it is.

TL;DR

Another very simple thing to check is get it warmed up again and then get to the monitor that looks like a little clock going round. Rev it until it breaks up and see if the clock movement gets uneven or blanks out or shows an error. The REM docs may help clarify this. That would be the computer losing track of the physical rotation of the engine so that it doesn't know when to fire the injectors and spark. That could definitely hold your RPMs down like you are seeing and make it break up as well. This could also be esoteric enough that a shop might miss it even after a lot of tests. Only problem with this is I don't know if the REM is good enough to detect and display this enough to actually show it. When I had something like this I used an oscilloscope to see that the injector and spark signals would break up.

P.S. On the idea of spark or cam timing. Is there any evidence that someone else had it open and got the distributor in a tooth off (quite easy to do) or that they replaced a timing chain and got the cam in a tooth off? That labored breaking up thing sounds really off and these could cause that. They are also deep enough under the pile of assumptions that a shop might not think of them as a cause.