MAN! I wish I were there. This internet business is like tying your shoes with chopsticks sometimes.

With notn' but a gauge you could check your compression while it's goodn' hot...of course freewheeling like that is a sign compression is ...spit.

 

Don't say that!

SON of a sea ****!!!

 

Ok since compression has come up.
I have read & been told that some of the early year renix 4.0 heads could have oil "seepage" on the passenger side of the engine kinda where the distributor is located. I didn't think a head could leak oil(per say) but my year seems to fall into that category.
I have a new VC gasket. It does not leak. I have determined my head gasket is seeping(not leaking). I never have to add oil. it's just not enough to worry about right now. But obviously there is a compromise just above the dizzy in the gasket.
Is it possible with the miniscule amount of seepage that this area of the head gasket is causing the "low" compression & as a result HNS?

don't say yes..I have left-over dynamite.......

 

Nah. Quit worrying about that. Flintstone got you started on compression cause you said "spinning".

 

Have you checked the voltage of the CPS with the engine cranking during the HNS condition? Are the CPS wire's routed correctly behind the head and out of the way of the exhaust manifold?

7th post down: http://www.cherokeeforum.com/f51/cru...x-tips-153657/

 

10 4 Brand new Mopar CPS installed per Cruisers tips & recommendations. Low res. & good voltage.

 

Not at all likely, but a few minutes doing a compression test is no big deal. If it leaks 40lbs of oil pressure, 2,000 lbs might be an issue. (or 110 lbs cranking)

Just a few minutes..if its turning easy, even checking just a couple might be enlightening.

If he had good blue spark, the Cps might not be it. Nonetheless, the test only takes a minute.

I know it's allot to ask..the Bosch # starts 280, the next three are 155, or 150, most likely. then there are three more. Just for "siIts and giggles", knowing that # might be fun.

 

So I'm going to go with the Bosch fuel system. What exactly do I ask for & where is the best place to purchase?

I'm speaking of the fuel pump. Do I ask for FP assembly & sending unit?

 

The sending unit is one assembly with the fuel pump. (they come out together.) IIRC the last pump I bought from Napa was just the pump, and I used my old sending unit. Above when I mentioned the Bosch numbers, I was just curious which injectors you installed prior to your problem starting.

 

Napa carries a Bosch replacement pump.

 

Thanks fellows. I checked my local NAPA & the pump price is $110.00. I've read where "go ahead & get a bosch"........"you'll spend over $300 but it's worth it."

Am I leaving something out?

 

The XJs came with either a walbro or Bosch pump initially.

At Napa, you can get a Bosch replacement for either one IIRC, about $110.

 

DFlint I'll have to look up those injector numbers. I do remember they are the single hole type. That was off of the hip back before I knew anything about what I might should be looking for.
My buddy at NAPA says the pump , filter , strainer will be here AM. $110.00 While I'm at it I may put a new tank in also. About a $100 for a new 20 gallon Dorman.

That sound about right?

Ok here's what I put in there. I just found the link.

http://www.precisionautoinjectors.co...7&categoryId=3

 

I might check the compression at HNS before I bought anything. Just me though, I'm pretty stingy. Not sayen that's likely, but hey, it's free, and you did say it "free-wheels", which might be tight valves or something....

So Precision sold you one holers for $130 and didn't provide a part #. I don't want to sound "to big for my britches". I'll just say OK. Guess they should be OK. If there was indeed a change from 18.6 lbs/hr, to 21 lbs hr from 90 to 91, that isn't your problem anyway. http://www.jeep4.0performance.4mg.com/tech_specs.html

The reason for my question is this. There are some LOW flow injectors out there, (14 lbs). After sitten hot your sensors might tell the ECU to go to a minimum pulse width. I wouldn't even suggest such an unlikely scenario if your situation wasn't so wierd. Doesn't really jibe with anything except your plugs being dry and clean. (they do go all the way down to 10# btw)

Anyway I'd save that pump that tests fine, under the seat. Probably I'd check the compression when it won't start, and also re-check that starting fluid won't make it start/run at HNS.

If you have fuel, compression, and spark, it will fire if it's not flooded. Gonna guess it's not "jumping time", then magically popping back when it cools a bit.

Guess that's not much help! (unless you find low compression).

 

The mystery lingers. I put the BOSCH fuel pump, a new strainer, sending unit, fuel tank, filter from NAPA in her.
Drove her 4 miles. It was warm here today so we got up to operating temp quick. Pulled over. Waited 5 minutes(with fingers & legs crossed)

Guess what. HNS continues. Hooked up pressure gauge & when hot I have 39 & 31 just like I'm suppose to. Smells like it's running rich.

I'm gonna kill somebody