AnotherOldJeepGuy

The shotgun approach was much more successful diagnostics. My spray bottle just was not shooting out enough water. With the hose, and the hose was not really on that strong more of a strong mist, the reaction was there almost immediately. Spray on the plug side didn't seem to have any effect, but spray on the injector side caused the rpms to drop quickly. I only sprayed from the top. There was some drop with spray near the back but in this case the biggest reaction was near the front. I sprayed primarily in a line from front to back just where the intake connects as best I could aim there anyway. Significant rpm drop, which did quickly cure itself when I took the spray away. So it would seem there is some leakage there. In fact I believe that if I held the mist at a particular front point for a bit longer I would probably have caused a stall. It does make some logical sense that the front is worse, and overall that this symptom appeared after a couple attempts to clean out years of old oil sludge. It seems possible that I just got lucky and "cleaned" enough of to expose small leaks that was previously clogged with said sludge. In any case, it seems that the bolt tightening suggested by @pizzaman09 could be the answer. Or it could be that 35 year old gaskets have run their course. I am not convinced my ESM degree (Enhanced Shad-tree Mechanic degree) is sufficient to replace both intake and head gaskets. Although I think I saw somewhere it is really 1 common gasket, I don't know that makes it any more likely my degree is enough! At least not until I get my car back from the shop so that I don't end up with zero transportation if I delve into this repair. Alternately, holding the rpms up enough to not stall is pretty easy. So I get why the water, if it got in to the air/fuel mix in the intake would bring down the rpms. Water doesn't explode at all the same as gas. But other than Jethro Bodine , I don't think anyone really believes you can use water for fuel. So the reason the leak is causing the stall is not water which was a diagnostic tool, it's air. Is it just that the extra air is throwing off the mix, or is there more to it than that? If the leak was a hose instead, would that have been doing the same thing or something different?

Got out my handy spray bottle full of water and proceeded to soak down every hose I could see, no change in engine rpm or sound. I also sprayed what I could from the top of the intake and header mating points with same results. I didn't climb under and try from that side yet. I used my spray bottle because I had good control of what I was spraying. I may try the hose next which will be a lot more water and not very well focused, so more of a shotgun than a rifle, but if I do get a response maybe I'll learn something new at that point.

Well since I do already have water I'll try that first. I don't know that I have any setup to allow introducing pressurized smoke, that's an interesting suggestion but I'll just hope for water working..

Interesting. I used up all my brake cleaner spray recently but will pick up a new can and give that a try.

Eventhough the scenario from @pizzaman09 does fit the symptoms, I have not gotten to the point yet that I can dig in deep enough to check for loosened intake bolts. In the mean time, does the soapy water test work for vacuum lines? I have yet to find any visual sign of a breach anywhere. And I doubt I'd be able to hear a small vacuum leak with the engine running, or even not running for that matter. I figured if there was a small leak I could not see, the soapy water test might find it so I brushed all the hoses and joints I could get to with soapy water while running and no bubbles seen anywhere. I understand that vacuum sucks, but it seams if the vacuum is not sealed, maybe it would be able to blow a soap bubble? If I can't see or hear a leak, it's pretty difficult to know where to fix it

As soon as I get the chance I am going to look at everything I can see from underneath for anything suspicious. If I don't see anything I am considering just disconnection what I can get to and cleaning it, and even try pulling and reinstalling the existing sensors, although if I can't get the sensors out easily I may not go to that step just yet. Worth noting that once the codes are cleared it does take some time for the ABS light to fire again, it's not instant failure.

Sure seems like it has to be a common "something"! Ah, I didn't think of it that way but I see what you are saying. Any past experience with "negative logic"? I still can't get past in my mind that 3 of 4 bearings, tone wheels, or fill in the blank, would all go out at the same time after all 4 being good since 1997! So what I mean by negative logic here would be a problem with left front, the only one NOT failing, actually being the real cause? Just wondering is anyone has actually seen such a condition....

The codes on Jan 2 were 31, 33 and 34, the suspicious "3 of 4 sensors go bad at the same time" scenario. The plan to recheck Friday fell through, so don't know if the same codes came back or not yet. If my son's busy schedule finds an opening one plan is to reset these again and the drive around until the light comes back and stop and read it again to see if all three come back at the same time. That plan would also include inspection to see if any thing looks disturbed visually. Would be nice to have live data, but I still don't have any tool that will read that and most internet research seems to suggest I'd have to get a pretty expensive unit for it to read this particular car. Seems like for Toyota you basically need a 21st century model for this for ABS info to be well supported.

Some time has passed and adding brake fluid seems to have stopped the BRAKE light from coming on (knock on wood). But the ABS light has come back on. My son is supposed to be coming back by today to reread the ABS and see if the codes are the same, or different. If the codes are different, and maybe even point to a single sensor we'll follow that lead. Also intent to just do a good visual at each wheel to see if anything looks disturbed. If however it once again show multiple sensors, any opinions on what might throw multiple wheel speed sensor codes? Will post back on what code reading are now, same or different...

Good Point. Fossil fuel = Fossil fuel.

Thanks for all the info. I'll post how it goes, perhaps with some along the way pics to document things for anyone else that might want to see them. I am supersized Expedition injectors can be used, learn lots from this group!

One of the 6 is leaking, but it is not constantly leaking. I did manage to catch a time of "leaking a lot" on video, but I don't know how to get a video from my phone posted here. I am about to start disassembly debug. I do have a new injector I can install, but I can't tell for sure the injector is really the problem. I generally can't catch the active leak, I can just smell it and notice damp parts. When I could witness gas leaking, it was puddling below the point where the injector is installed into the engine, and I still could not see exactly where it was coming from. But if you compare the leaking injector to one that is not, it appears the injector is damp from top to bottom, suggesting the leak might be at the highest point, or, it was being squirted upwards and I just don't get to see that (and I don't see evidence on the inside of the hood to suggest anything has been squirting upward). During the time I caught this actively leaking, there was smoke coming out in a few places out from under the heat shield, I presume it was the leaking fuel being heated on the intake and evaporated. When I can't see the active leak, I don't see the smoke either. Note that I replaced the rings on all of the injectors about 6-9 months ago because of smelling gas and at lease one damp injector then (I think the same one but not sure). Since I had it out I replaced all the o-rings. I did not like the new o-rings because they seemed fatter, and because of that were very difficult to insert into the rail. The ID seemed to be sufficiently similar. What I didn't like was that the original (broken) had a flattened outer edge, the new one was round. I didn't have much luck finding any new ones that were flattened, and decided to assume the original may be flattened by being under pressure and heat for 30 years. So, most of the above is posted for comments at the moment, since as far as I can say right now, the only actual question I have is, do I need to get my hands on "pre-edge-flattened" rings, and if so any suggestion on where and/or part number, or are the new donut shaped ones OK (albeit very difficult to push in)? Thanks

I put checking that on the to-do list! Some repairs have to wait until I have both hands functional (got a splint on one at the moment). I took a road trip over the weekend, about 500 miles. Made it there and back so my issue is not terminal yet! I have an injector leaking now that may have been leaking less previously. Don't know if that would cause the problem but it does seem possible. Anyway, it is a visible leak so I don't need to guess if it needs fixed or not! Luckily I picked a new one up at the Advanced Auto closeout so I have one on hand. Always something that can be done to this old truck! If that gets too interesting I'll probably start a new thread on that repair (or find an existing one to add to).

Test drive completed, no change . I was not that surprised since most if not all of these connections did not really look like they were intended to be airtight. But even though they didn't change this particular issue, it probably can't hurt for these to be more snug anyway.

I have a new one in there now. I waited until I had the replacement in hand since I expected the something to break, and it did, working the old one off. The rubber at the engine end ripped rather than pulling off. So if the path was clogged in the hose before it should not be now. It was a bit of a struggle getting the new grommet in at the valve cover, but got it in there. Time will tell if I can tell that I actually accomplished anything useful .

I found only 1 actual opening so far... a mystery hole just before the large air hose to TB. I added a few snug zip ties where things were fairly loose. I don't know which if any of these are not really intended to be air tight anyway but they are more snug now. Now off for a test drive to NAPA to pick up a part on order that came in. Will make note if any of the tendency to die has changed.

Mine appears to have a recessed cover of some kind.

Nice write up, someday I may take on that update. AFAIK all the hands on junk yards in a 50mi (or larger) radius from Plano are now extinct! So I don't figure I'll have that option, but I'm guessing EBAY might work well. Anyway this one is on the to-do-a-bit-later list

Nothing is unplugged intentionally anyway and no plumbing has been touched any time near when the problem came up, unless accidentally. I'll look more closely just in case. I pickup up new Throttle and Crank Position Sensors in the Advanced Auto close out, one for $3 and the other for $1.80 (last one they had of each), so I can experiment with swapping if I need to. At least the TPS looks easy to get to, I've read the CPS is not.

@Salvagedcircuit I had not thought of heat shrink repairs. If I can find a leak I will keep that in mind as an option. The tapped repair from cruiser makes sense but seems a bit more risky, but doable for sure. I like you house routing much better than mine. Is this your design or an improvement from the factory? The way mine is is not modified by me at least, and I am the original owner, so if it is different from stock on mine I'd have to guess its part of some repair shop work in the past I don't remember. My hose routing interferes with changing the air filter much less that how yours is routed so if I have to rework this area I'll shoot for something that looks like yours.

Thanks @GonzoTheGreat The assembly to the left as pictured is newly replaced, about 6 weeks ago. It got broken when I replaced the valve cover gasket. The half to the right is original. Since this issue didn't happen then, just happened at the cleaning, perhaps I "cleaned" off some crud that was sealing the system. I'll try looking closer.

Tagging in here since my new symptom is the same. and this thread seems to be current. I recently tried cleaning up all the oil/crud in the area below using Gunk engine cleaner. I went through the process twice. After this I have this same dying issue. For the most part it dyes if I completely take my foot off the throttle. A scenario that is pretty repeatable is to come out of the local grocery, start up fine, start across the lot a bit and take my foot off the pedal and it will die. Only the area pictured was included in this cleaning. What is in this area or below it that got messed up? Is the CPS in this area?

Great! I didn't use the right word soup in my search

Was able to read the ABS Blink Codes, said 3 of 4 wheel speed sensors were complaining. Since I have a hard time believing 3 sensors just went bad simultaneously after working for 28 years, I opted for resetting the ABS codes (found a way to do this without a meter as well). Also added some break fluid since it was setting just on the MIN mark and my son said the Brake light was coming on just when taking a long left turn. Went on a 20 minute test drive, which included a visit to a vacant lot and getting in a bunch of long left turns, and slamming the breaks enough to get ABS to engage at least once, and so far, , no Brake or ABS lights. I'll believe it is fixed after some time passes, but good for the first few minutes at least.