zjrog

Well then, last night I went out to check on the following, fuel pressure is nice and squirts quite well, across the RPM range. And I changed the fuel filter last weekend. So unless I have bad injectors, or so I thought last night, it must be somethieng else. Next I tried to backprobe the cam sensor connector, but my little cheap digital meter doesn't have long enough probes, However when I disconnected the connector, I had a good ground, a 5 volt line and a 8 volt line (not sure what the 8 volt is for though...). I also pulled the dizzy cap and the pulse ring was tight (I had already replace dthe cap and rotor and all looked great...), removed the pulse ring and didn't see any damage and the cam sensor looked to be in good shape visually. I broke out the ancient tech timing light, and while I didn't spend much time cleaning the harmonic balancer or the markings, across the RPM range, the spot I fixed on stayed pretty much in one spot. It was starting to rain at that point last night so I buttoned everything up and called it a night. This evening, my buddy brought over his compression tester. We originally ruled this out a couple weeks ago because we THOUGHT the idle was OK and it wouldn't idle if the headgasket were bad... Well, we were idiots. So, if I recall this correctly, we had 150 in cyl 1, 142 in 2, 135 in 3. See a trend? 120 in 4, 90 in 5 and 126 in 6. So, we/I wasted 2 weeks and more than a few bucks. But then again, now I kow certain things are just fine. But it looks like I will be doing the headgasket this weekend. No great mystery, as I did the headgasket on my ZJ last year. And while we have the head off, I'll do a quick look at the pistons and see if maybe the rings are OK or not. Easy to check with the head off. Though, it kind of makes me wish I had done some things a little different. Last year when I bought the XJ, I ALMOST picked up one for parts. The idea was to tear the motor down and rebuild it just in case. Now, I wish I had. Can't go backwards. So at least I know what I'm doing this weekend... :mad: Thanks for all the ideas though!!! :cheers: Edit: My friend actually wrote the numbers down, I went off memory... I guess I shouldn't do that... 155 145 130 120 100 140 Either way, 5th cylinder is dead and took a couple with it.

4.0...

SO I stayed up too late last night, and sitting at work this morning got a call from a friend of mine with more EFI knowhow than I have. Adn he agrees that the chain isn't the most likely cuplrit. But he was asking about the cam sensor/synch generator. Does the pulse ring in the distributor have just 6 windows in it? Or like other systems, does it have a high resolution and low resolution sensor? Seeing there are just three wires I'm guessing just the 6 windows for the pulse ring. Can't seem to find a picture of the pulse ring other than straight over the top. Sucks to be at work when I want to work on the sick beast.

I'll do the timing light tomorow evening then. Thanks. That should at least tell me if the timing chain is OK or not. I guess I already said it, but thanks for the advice and the figurative kick in the keester...

Gee, do I even have ye olde timing light? I'll have to check... WOW! I still have it! Haven't used it in at least 10 years!!!! So, tomorrow after I get home from work, I'll warm up the sick beast and run the timing light. So, am I looking for the timing to hold steady at idle, or will it bounce around some? Or bounce a round a lot? I'm REAL rusty on ye olde style mech troubleshooting. Damn computers... Let me backtrack and fill in some details, since my original post was also posted on my local club board. Ever since I bought this back in December, it has had a bit of a stumble at throttle tip in. doesn't matter what throttle position, vehicle speed or just idling. My daughter drove this rig over the many months, often for hours on end on dirt trails (nothing difficult). I've driven 100 miles roundtrip a couple times with no problems. So it was a surprise when the XJ started skipping and missing and losing power. We limped it the rest of the way to the nearest town as it could be revved to keep it at speed when floored. In the last mile before entering town the temp light came on and I drove the last mile anyway. Once parked it was apparent it wasn't going anywhere on its own, so we rented a Uhaul dolly and dragged it behind my ZJ the rest of the way to school (the XJ was loaded with my daughter's stuff since we were moving her into her apartment at school). By the time I got the XJ home, my ZJ had been abused for over 200 miles and I ignored the XJ for a week. With everyting I've done now, i haven't even tried to drive it because it still skips badly when I run the throttle up. But it still idles smooth and can be revved above about 3000 RPM. I'm frustrated but the rig is well worth saving especially since I just had it painted a month ago... John Deere Yellow...

I was wondering if the cam sensor/synch signal could be my culprit. If it were the crank position sensor, it would stay running at idle for nearly an hour and would be very difficult to start (unless I'm missing something...). Thanks for a different direction to look for.

So the story of the 90 XJ from hell has already been told. But as a reminder, it started running like crap during the a simple drive to college, and ended with overheating and making it home behind my ZJ. The XJ is a 1990 with 199,000 miles on it and probably needs a bunch of stuff swapped anyway. Also, someone used to like this rig and took care of it. Evidenced by past work in front and rear diffs with non-original sealant and a newer rad and waterpump and other parts. After a friend of mine stopped by and we are comfortable that the headgasket isn't trash, we decided not to run compression test. Also, it was decided that I need to run some Seafoam through the tank and the motor. Admittedly, I was awefully frustrated and didn't really touch the rig much. I did talk with another friend (who used to work for Year One) about EFI and I did try a couple things. I unplugged the O2 sensor and all I really got was some backfiring that I didn't have before. I also repalced the plugs and distributor cap and rotor. I didn't replace the wires (yet) but had spark at all 6 wires anyway So I went about trying to find the coolant leak and decided the radiator had sprung a leak somewhere. Couldn't repeat the issue, but didn't trust the rad. Considered a three row all metal unit, but this rig won't be a hardcore offroader nor will it tow. It will see some minor trails and in the future a 2" lift on 235/75-15s. Back to the task at hand, the rad was replaced with a single row stock replacement. Again, some stuff looks newer, so I reused the upper and lower hoses (they both still have tags on them!) and feel pretty solid. However we went and replaced all the heater hoses. Again, the waterpump appears newer, and the thermostat appears to have been replaced, so I left them alone. For now. Along the way, everything has been flushed, tons of chunks came out of the heater core and now we have heat in the cabin (my daughter will appreciate that in a couple months). I also checked grounds and it seems they are all in place, but after some more thought, I'm not going to trust them, and redo every @#$%ing ground, even adding some for redundancy. When I did the grounds on the Ranger, I probably overdid it. But I don't ever want grounding issues to sideline the Warthog. Likewise, the XJ is for my daughter so I don't want it stranding her due to grounding issues. Kind of the same reason I gave a friend of hers a spare tire and wheel. My daughter will be riding in the friends XJ and a real spare instead of a doughnut will help them both. So, the O2 sensor was replaced, Seafoam sits in the tank, hoses and rad replaced, new fuel filter installed. I will say that the thing is starting a little easier, but still runs rough above idle until about 3000 or more RPM. Seems the Throttle Position Sensor had been replaced before, I felt it might be bad, so, the replacement came in today and I swapped it over. Previously, the lower mounting screw had been cross threaded or such and is really munged up. It has been slightly modified now to fit a standard 8-32 screw. I followed the TPS adjustment, setting the proper 4.2 volts at throttle fully closed. Finished putting all the vacuum lines back and started it. Damnit, no real change. WTFO? Twice today, I had the XJ running for better than 45 minutes at a time. No overheat sitting. I do not have the front header panel in place, so I'm not driving it around town to see if it overheats while running it badly.... I did run Seafoam and let it sit a while and restarted it. Neighbors were outside and thought I'd lost my mind and finally decided to burn it to the ground. Smoke cleared but the thing still doesn't run right. I did spray just about everywhere there was a vacuum line with some brake cleaner. The thought process being it would either rev or want to die, but no, no change. So what I'm considering next, whether it makes sense or not, move the distributor back and forth in case the timing is screwy. Maybe the MAP sensor is whacked, or maybe replace the intake/exhaust manifold gasket. I'm just not sure what to try next. I'm at the point now of not wanting to spend any more money without a better direction to aim for. The sooner I get this done, the sooner I can decide if I'm fixing the Ranger front axle or going solid. Ideally, I want both rigs done before snow flies. Because I want my ZJ back so I can do the lift and throw on the 31s. Ideas and thoughts are more than welcome here. I'm frustrated and at my wits end.

I don't see anything suggesting GT... My mom got fooled with some non-original GT stripes on a '66 25 years ago. At least it had a 4bbl and disk brakes. She was upset when I pointed it out to her... But we upgraded it with the Monte Carlo bar, and exhaust, bigger 4bbl and some better springs. Might not have been a GT, but at least it ran like one. For the most part. I've had 2 65s, a 67 and a 72. I'd really like that 72 back...

I'm still recovering from back issues too. Been able to stand up straight for a little over a week now, but the previous three weeks were MURDER! Still had to work on my daughter's 90 XJ to get it ready for her to take to college. And the POS crapped out on the drive last Saturday to school... Dragged it on a tow dolly behind my ZJ... Hope your back feels better soon...

Half gallon of John Deere Yellow, marginal prep and over black paint even. Took three coats... And below, the Ranger is painted with a local ranch store camo paint, 2 quarts... A friend of mine squirted both paint jobs. The yellow is realy farm equipment paint. The OD green went on real easy according to my friend. Both paint jobs were done in my garage even...

Hey fellow Sailor! I retired too, 7 years ago. My younger sister went USAF in a nursing program. She signed up sort of late in life and had a bit of trouble with the PT but she got up to speed... But, currently she is on a deployment bubble, just waiting to hear when... Godd luck with your girls... My own is starting college this fall and has no interest in military service (and has some minor helath issues anyway...).

Friend of mine has the manifold and gauges. There is some refrigerant in the system, but not enough to cool. I've used retro kits before with some success. Though they never cool as good as either the factory R12 or R134A. But its better than sweltering. But then, I'm not driving it, my teen daughter is. I ain't driving it wit Hello Kitty crap all over it... The setup on the 90 XJ is different than other systems I've recharged. I've got the 88 manual that circules around the web, but it doesn't seem to cover whats under my hood.

Easiest way to recharge the AC in a Renix 1990 XJ? OTHER THAN take it to a shop...

Autozone sells a Cherry bomb brand turbo mufler for like $22... Put one on my daughter's 90 Xj 4.0 and it sounds great. Cheap and good. Now my old minivan I had a CB glasspack. That was loud...

Just watched the last episode of Gearz, and I really want a V8 barstool!!!

There seem to be more Renix folks here than at NAXJA... 90 XJ 4.0 runs pretty good most of the time. But. Just as you step on the gas, or add a little more throttle while driving down the street. Other than that, it runs good. Ideas?

I'm going to use a 8.25 in place of the Ford 7.5 in my Ranger project. Going to 4 link it after tax refund... Price was right, the axle was free, the coils were free and crossmember material has been free. Doubt I get link material and joints free though... I think the 8.25 is highly underated, the later models have 29 splines and are regarded in some circles as nearly as tough as a D44. Certainly an improvement over the D35 or my Ford 7.5...

I have a question about stroked/turbo'd 4 liter motors. Well, more like fuel injecotr/ECM questions. I have worked with the Chrysler turbo cars form the late 80s and early 90s, as well as prepared a V6 minivan for a turbo (that never got finished due to the van getting junked). For Renix and HO were the injectors and ECM drivers high impedence or low impedence?

I keep thinking of a 51 Willy's cab a friend of mine has... If I wasn't hip deep in a cab swap project, with a possible XJ project coming in days, I'd love to rat out the 51. Use a modded 4x2 Ranger chassis. And just to be odd, a Chrysler 2.5 turbo motor with intercooler. 5 speed from a Dakota. I just think a Willy's truck would be so different. Bed would be handmade, and just long enough to get a bumper behind the rear tires. I know of a T bucket rat getting an SRT4 motor...

Glad you are still with us brotherman... I work 10 hour days, 1 hour drive each way. Luckily, we only work 4 days. THough when things get hectic there are more days and more hours. Though, they try really hard to get us 8 hours between shifts. Part of my daily drive is mountain pass, and lots of twisty road. Not to mention idiot drivers and some thinking they are speed racer. Oh yeah. Deer too. Glad you are OK, a Jeep can be fixed/replaced... :cheers:

I have the 242 in my ZJ and love it in bad weather and snow. It helps offset my overly tight limited slip (which is acting solid right now :roll: ) in the snow. Much fun! Stay away from the 249 in early ZJs, it was only AWD and didn't have a lo. Later models had a lockable lo... But stay away from it, the viscous coupling is expensive when it fails.

Yup, forgot about the whole of the West Desert... Strange, since I WORK IN IT!!!! Funny thing is that truck is only 90 miles form where I used to live. That IS going to be a kick @$$ truck when its done. If you like the desert racer thing.

I'd love to see that thing at ride height!!!! Wouldn't do me much good here in Utah, need 4x4 most place I go now... Hmmm, wonder how quick that would run the Pony Express Trail!

Reading through this I got an evil grin... Take one wrecked or rusted 5.2 ZJ, and swap all the pertinent parts over to the MJ! I would think a NP242 would be preferred since you are looking for AWD in a pavement pounder. Link and coil the rear, but watch your anti-squat numbers, You want it to launch but not look like its reaching for the sky. And the 5.2 could be tuned up a bit. Use both ZJ sway bars. I couldn't imagine needing anything lower than 3.73s... And if you found a 98 5.9 ZJ that was trashed, well, no replacement like displacement! Cut some cooling vents in the hood though... Just my useless opinion!

If everyplace that had trail closure issues did this, we might be able to finally get a handle on the enviro nuts. Trail education is a must if we want to keep enjoying our freedoms. I myself, wasn't able to attend, but did help spread the word. Sadly, I couldn't attend due to work issues (I'm by myself in a 3 man shop and things are busy right now). The guy that organized this event was telling me Tuesday night he was hoping for 80% turnout of the people that said they would be there. He organized the groups, garnered some sponsors, ran the permits and scaled down some of what he wanted to do. We really wanted to get permits to allow trail rigs to participate, but there just wasn't much any way to get that this time around. I do believe though, that if one man can organize something like this, it will be easier to do next time, and 84 4x4s DID get noticed. As for my issues, anyone with electronics expereince need a job in Utah? PM for details. I'm not the hiring official, just trying to help out. :USAflag: