deucetrey

Hi there, new to the forum here, wanted to introduce myself and ask a question or two....great place by the way with all the info. I go to a similar forum regarding my Subaru WRX, pretty cool how people in these communities help each other out and can spread the word about fixes, mods, etc, without getting ganked at a dealership.

Ok, so I have a 91 Cherokee Laredo. I6, odo reads 212k, but it's broken. The engine is from a 92. I bought this fine rig, named Samantha, 2 months ago for a work vehicle with some playing on side. $1000, so not a real big investment. All seemed to be running good until yesterday. Got low on gas, put in some fresh 91, on the way home it stalled a couple of times. I wasn't sure if it was maybe bad gas, since it was an out of the way station, or what. I put a bottle of Heet in the tank to make sure there isn't any water in there. Head out to work this morning, and after it warmed up pretty good, the enging cut out, and came back on a second later. I pulled over in parking lot and noticed that this was leaking...from where the metal rod goes in between the two screws..

I can't seem to find this part in my Haynes manual, but the guy at the auto store said it's for flowing coolant to the heater core, and that's it. He stated that this wouldn't cause any engine problems.... is this correct? if this part starts leaking, 1, is it a vacuum leak? and 2, would this somehow be affecting my Coolant Temp Sensor, causing a bad signal to quit sending fuel and/or air?

After reasearching on this site last night, I know I should clean a couple of things up, like the IAC....

Any help is appreciated.

OverlandZJ

He's right, it's your Heater control valve. If it's leaking you need to replace.

Betting your issue lies elsewhere.

bigomudders

heater control valve

bishop letov

that valve just shuts off low of coolant to the heater core so that when you have the heat off the flow of coolant to the heater core is bypassed (shut off). Nothing what so ever to do with ecm controls but could cause a overheating issue if left to leak coolant.

Just replaced mine when I did the rad update to the later style open system from the leak prone closed system.

deucetrey

Thanks again for the info...

picked up a new HCV at the dealership, talking to the parts guy there, he asked if it was pretty hot out when it stalled, which it was, because he mentioned some older XJ's suffer from vapor lock. I'm in Denver and we're starting to see 90's here. I think Bishop hit it when he said the leaky HCV could cause overheating too...until today, I don't think the old HCV was leaking too bad, but today it was spraying out, and the heat radiating from the engine felt a little hotter then normal when I popped the hood. I have noticed my temp guage fluctuating a bit the last coupla days, instead of just sitting steady also. I'm gonna do a flush and fill since my fluid looks a little old, and will most likely do the thermostat as well.

I'm wondering if the combo of old antifreeze not cooling as well as it should, the leaking HCV, and the hot temps are combining to cause vapor lock? After reading a bunch here last night, it seems like stalling is a common problem, with uncommon solutions.

prerunner1982

I have a similar problem. When it is warm out my truck will no longer accelerate. It won't die just won't let me push on the go pedal without hiccuping and coughing. I will turn it off and let it cool for a few minutes. Starts right up and goes until something gets hot again and will do the same thing. I did not think of vapor lock but since it is not completely stalling I dont know. I have not had this problem this year (knock on wood) and it has been 100* lately. I hope you can figure your problem out.

redhandstudios

Mine used to Vapor lock at warmer temps in higher altitudes. I bought it in Portland (near sea lvl) and moved to Bend (much...much higher elev) I wrapped my fuel rails in heat reflective tape and that took care of the vapor lock issues.

Jason248

It sounds alot like a Crank position sensor issue, my grandprix did literally exactly the same thing you are discribing and the CPS fixed it. And they do go bad in the 4.0s alot as anyone will tell you

-Prerunner it kind of sounds like you have cat issue

dellstopjeep

my money is on the cps.

coyote121403

I also live in denver and have a 91 with the same problem. Runs for a bit then dies... let it sit then it runs again...

jd4x426

sounds like a cps to me this is a very common problem with these rigs as said before

prerunner1982

I replaced the CPS on mine thinking it was the problem and it was not.

Jason, would a cat issue only happen in high temps? What kind of hairball treatment do you recommend?

Programbo

Those plastic heater control valves are really prone to leaking once they get some age on them and you move them around..If you leave them alone they are fine but if you are always in there digging around in that area you tend to have to push them aside a lot.

Jason248

when a cat overheats yes, ive seen it alot, just had to swap one out on my mothers car that was doing the same thing, easy way to check is to pull it off and throw a pipe the same length in and see if you still have the same issue, if you do look elsewhere if not you know what the problem is

deucetrey

So I changed the CPS today, and lo and behold, there was much rejoicing.

I tried a few things on the way to my friend, the CPS, hoping to avoid what looked like a large type pain in the ***. I also did the thermostat, and flushed the radiator as well, followed by the fuel filter, and just yesterday picked up a fuel pressure gauge to make sure it wasn't the fuel pump before getting to the dirty little sensor.

I did this tip which made a huge difference....40-50mins of banging around against the bell housing to no avail, to being done in 15-20mins.

Tech Tip: - To more easily remove & replace the CPS use a floor jack to support your transmission cross member, remove the two bolts & two studs (replace those with bolts if you break one), then lower the transmission cross member by about 1-2 inches. This will give you enough room to get your hands & tools in for the CPS work. (Especially if you have big hands!)

This saves much hassle and I hope me posting it will benefit someone having to deal with this problem.

Thanks again to this site for help trouble shooting.