flint54

Cruiser, you might get the prize! That is something that also came to mind as a possible solution. My 62mm TB does have such a screw (at the linkage) and I could easily try this, while watching the RPM so as to not raise the idle too much. As you say, it would reduce the possibility of close-fitting butterfly compounded with high manifold vacuum being the cause of this issue. I will post the results tonight.

To check that box, I tested fault codes and got only "55" (end of codes). Tomorrow I'm going to install a NOS IAC I scored, just to rule out a sticking plunger, even though there's no mechanical relationship between throttle and IAC. If money was no concern, my solution might include one of these: http://www.4x4community.com/forum/showt ... hp?t=30945 Sometimes I really do miss carburetors......... 20 inches vacuum seems like an indicator of really good motor health, probably higher than many, but not excessively so.

"lack of torsional rigidity"....Exactly the words that came to mind as I looked at the images. (either that, or the driver has some real serious digestive issues.....) Seems to me that in order to get this much flex this high on the body, there must be other weaknesses down lower. Imagine pinning LF and RR to the ground and quickly lifting RF and LR, and then reversing, repeatedly. Real hard on sheet metal. You could weld it, but you can't solve it, short of a roll cage.

If your tires have more than a few years age they can degrade internally even with plenty of tread. The result -could- cause what folks cause DW. That was my case. Step one was to road force balance (not just spin balance) which solved ~75% of the DW. New tires and another round of RFB made it smooth as it should be. How bad was it? A white knuckle, seat soiling, experience, wondering which ditch I was about to land upside down in. As others have said, track bar is the second leading candidate.

When I visited the precisioninjectors folks, it was explained to me that these caps need to remain installed, they're part of what makes the spray pattern. I don't think that's a big deal as long as the fuel mist is fine enough so it mixes well with the air in the manifold. If you look into the manifold bore where the injector seats you will notice a lip that this cap bears against. It's not going to pass this lip if it came loose, and it's very unlikely to come loose. My puzzlement was that the original injectors, the ones that chrysler put in when they built my truck, had no such cap.

Carnuck you're shooting from the hip, and not paying attention to what I write. From most recent post: Throttle plate is tight, centered, smooth edges, and pristine. TB is nearly new, and no marks on the bore that would suggest any hangup or sticking due to fit Even if they were loose, which they are not, why do you think that would only be an issue when moving?

Swapped in a K&N cone system (FIPK) tonight, and found something that really surprised me. One of the tabs on the outboard side of the stock airbox had been making contact with the harness that feeds the PCM. The tape wrap was rubbed through, and the insulation on one wire was halfway rubbed through. Not sure which wire, but my guess is they're all important. If you have a stock airbox, check this out. If close, recommend adding some form of chafe wrap. Yes, the airbox was tightly mounted. BTW, the FIPK system is dimensionally incompatible with a throttle body spacer. Hood won't close. You can have one or the other, but not both.

Nope. Let me recap: truck off - throttle moves freely ignition on (not running) - throttle moves freely motor running (but parked) - throttle moves freely driving (<10 mph) - throttle moves freely driving (>20 mph) - throttle sticks badly IAC and TB are very clean. Throttle plate is tight, centered, smooth edges, and pristine. TB is nearly new, and no marks on the bore that would suggest any hangup or sticking due to fit. Cruise cable is disconnected. This all began less than 300 miles ago, midway through a trip. Nothing was altered. I cannot convince myself that manifold vacuum is a factor, but nothing else makes sense either. Vacuum reading is steady 20 in. at idle. Pop the throttle and vacuum spikes low, spikes high, then returns to steady 20 in., exactly as it should.

All great tips, thanks Don. Unless I up the displacement (on my "dream about" list), I'm going to just keep the stock header - don't see any reason to change it out-yet. Also, I'm probably going to go to AN-type fuel lines. Something about high pressure fuel, in plastic, next to high temp parts, just bugs me. Seems like I have 5 or 6 vacuum lines right now, but should be no big deal to gang some of them together. Finally, I'm still figuring the gasket dilemna. The good folks at FelPro list gasket "X" (actually MS94790) for the 1992 and gasket "Y" (MS93094) for the 1999. The bolt pattern and port spacing appear same (haven't laid them both together yet), but the exhaust port holes look larger on the 92 gasket. Might have to do some gasket trimming? Thanks!

I'm collecting parts to swap in the '99 intake manifold. Scored the manifold, along with PS pump and bracket, at the JY yesterday for $50. Took it to the hot tank folks today for cleaning. This looks to be a pretty straightforward swap, other than the difference in vacuum connections. Anyone who has done this, and is willing to post an image of those connection changes, would be a hero. In figuring out the belt difference, I made this image that shows the routing difference and part number difference in case anyone else is thinking of going down this trail:

Carnuck thanks for your input but did you read both of my descriptions? The part that says everything moves freely? Motor off, and motor running but not moving? My sig that says AX15?

I have had a similar problem on a different vehicle (non Jeep) and it turned out there was corrosion in the connectors. Symptoms very similar to what you describe. Scrubbed them well and them applied that anti-corrosion goop they sell in the bulb section to the connector terminals. Problem solved. Perhaps this could be your issue as well?

The IAC was a good suggestion, even though it was new last year and my idle is perfectly smooth. To be certain, I pulled it out and found very little contamination, which I cleaned anyways. Made no difference. Here's one more clue. The sticking only happens when I'm moving. When I'm sitting still, truck running, there is no throttle hesitation at all, not one little bit. As soon as I'm moving, if I let off the throttle completely, I have to tromp on it to get past the resistance. Most puzzling.

Appreciate the reply, thanks. For this purpose it needs to be functional.

This one baffles me. When (and only when) the motor is running, the throttle feels like something is holding it closed. I have to step on it hard to overcome the resistance. The pedal freely pivots, the cable freely slides, and the throttle link and plate operate by hand freely. When the motor is not running, the pedal is smooth as silk. The throttle body is clean as new. I even disconnected the cruise cable to make certain that wasn't a factor. This just started a couple days ago on a road trip. Once the initial resistance is overcome, the throttle is smooth throughout the rest of the range of motion. It seems very improbable that manifold vacuum could cause this, particularly since it just started happening. Anyone have a clue what's going on?

Well, I will, respectfully, offer a different view. I would switch to an automatic belt tensioner in a heartbeat if I could find that this has been done before (I have not yet found it having been done, even though have asked around here and elsewhere). I have had many vehicles with this spring-loaded device, and yes, they do fail sometimes, but I've never had one fail in less than 70k-80k miles, and they're cheap and easy to replace. A worrier would do well to carry a spare. Tensioning the belt by adjusting (beneath) the PSP is a royal pain in the a$$ comparatively. two cents...

I am looking for a couple of these, don't care if they're in poor condition. Free (I'll pay shipping) or nearly so preferred. Don't need the rods, only the center assemblies. I have a wild idea to design a locking handle and would like to attempt a couple prototypes. Thanks!

Thanks for your speedy reply! To make sure I understand you correctly, you are telling me that that the aux fan is required to run so as to pull air through the condenser, or else the refrigerant pressure can become excessive? I surely do not want to blow out the AC lines (since they're pretty corroded anyways), but I have to wonder how high it can get (without fan), how high is excessive, and whether the system has a high side cutout (or bypass relief?) like many systems have cutout for the low side being too low. Since a lot (most) of my driving is at high speed, I was thinking the fan doesn't need to always run, but if moving slowly I could switch back on the relationship. I really doubt I need that fan running when I'm moving at 75mph (and would like to shed load, however small, when I can) Found this:http://jeep.zerok.ru/files/XJ1984-1991/acsystemdiagnosis.pdf which suggests high side could reach >350 psi on very hot day, but for me I should expect to not exceed 260-270 normally. Suppose I could just sit without the fan running and watch a high side gauge to see what it does?

Well, I tried to search, because I think I've read this here before, but our search tool will not permit only two characters, like "AC" which is frustrating. Now that I have abundant cooling, I would like my LH aux fan to NOT come on automatically when AC is running. Want it temperature-driven only, at 220 deg. My RH aux fan triggers 50% at 205 deg and 100% at 210 deg. Being no electrician, I can follow black lines on a schematic all day long and still not be able to point to the part on vehicle. What I actually want is a trial separation rather than divorce, who knows where (if) I can easily do this? Perhaps even add a switch so they can still date each other? Thanks!

I am looking for the black switchplate emblem that shows both fog light and cargo light. I have emblems with one or the other, but not both together. I'm tempted to just cut two halves and join them, but would prefer to have one with both. Thanks!

Fifty bucks for a track bar bracket?!? That's insane!! I'm going to the boneyard tomorrow (for a different part) and I'll try and find a good one. There are about 50 cherokees typically in my regular boneyard. Online dealer price for part number 5200-7121 is $159.60, which is even more crazy. I am appalled. It's just a damn piece of stamped sheet metal with a few holes in it, for cryin' out loud. Maybe I oughta pull every one I find................

I wouldn't waste time or effort on a used track bar unless I was in a real bind. They're readily available new from multiple sources and don't cost a fortune.

Depending on your confidence level, all gauges are unnecesasry to the operation of the vehicle.

:agree: , and when I had to replace mine I looked for an XJ that was unmodified and newer. Also checked the TRE hole very carefully after pulling. Think the mount cost me $5, and perhaps 15 minutes.

Well, I'm stumped (not all that hard to do actually), you have a genuine perplexterious mystery. Unless somehow (and not likely based on your provenance comment) that trans had been altered before you got it. But how? why? Makes no sense at all. Oh well, this presents you the fine opportunity to get that 6 speed box and 4wd conversion you know you want. Good luck, and if you pull that shaft it sure would be enlightening to see an image of it. You took a FL truck to where?!? That's grounds for flogging! Hope it at least has a good wool blanket.