DFlintstone

Oh, not to be argumentative, I believe the movement, and description of heat, does indeed fall under the definition of physics. Btw, I see now that you mentioned dealing with the "failed TPS" code as well.


Olds! Hold on, humanity as a whole.....well, let me rephrase, don't give up!, there is plenty of good out there! You are intelligent, experienced, and appreciated!

OP, I know you are a pretty experienced guy. I gotta wonder, for just diagnosing, (besides swapping the TPS), why not just wrap a bunch or Reynolds wrap in there and see if anything changes? (or apparently Rrich prefers, and has plenty of gum wrappers)

Last, when I had a somewhat similar problem, it took me almost a year to figure out that heat expansion was shorting a sensor wire when I was parked. Once or twice I didn't turn it off all day! (fix took 5 minutes).

Radi

All this gum wrapper talk has reminded me of one of life's big disappointments.
Nobody pays me in gum. Nobody.

rrich

He He - melted/shorted wires are an entirely different problem. Wrapping - the movement - may cause them to stop shorting, or may even make it worse - or the tinfoil could short it more.

Yesterday I was helping a friend - 87 Dodge Dakota with a similar symptom - no or rough start in Hot soak, and intermittent stalling at all temps. He's been fighting it for several months. A few times it didn't stall, but ran really rich - clouds of black smoke. Of course it wouldn't do it for me - always ran fine for me.

I hadn't even put the pressure gauge on when I looked closely at the wires to the PCM - it's right on top of everything. Something didn't look right. The rubber boot was slightly bulged. I pulled on the harness - a wire and the harness connector pin came out. Further pulling I pulled out 2 other wires - with the pins. Rats had been having lunch!
Mitchell Computer Manual said one was power to the ECM, one was O2 sensor, the other the fuel pump relay.

It was a fluke that I found it!

Now the problem - getting new pins for it. Dealer said "no way!"
Probably a wrecking yard part.
Can't declare it's fixed until proven that it is.

But it goes to show problems are where you find them. Some are easy, some just lucky, some hair pullers.

Rats, mice, rabbits etc can really create problems. 2 years ago I parked my highly built GEO tracker rock crawler in one one of my garages. A few weeks later I went to start it - didn't hear the pump running. When I opened the hood a huge fat rat was staring at me. He was at least as big as a rabbit! He ate most of the wires from the ECM back to the pump! No wonder he was so fat! Still haven't fixed it yet - no time.

He He - There are TSB's about rats, rodents, and even bees!

djb383

Dayum........Jekyll and Hyde.

rrich

"""""Nobody pays me in gum. Nobody. """""

Probably a good thing too.

Imagine when the IRS says you owe them 3,547,122 individually wrapped gumballs.

Think how many Cherokees these guys could fix!

DFlintstone

Ironically, it was my heat shield, shorting the wires to my knock, ct, or 02 sensor.

Not your issue of course, my only point there, when heat migrates, it CAN short a sensor wire.
(That harness is now routed better)

the buddmang

Lets break this down so you can /maaaaybe/ grasp it.

TSB - Released to dealerships/public by the manufacturer as a PROVEN repair to a common issue. Repairs are authored and confirmed by Master Technicians AND OEM ENGINEERS.

chnical service bulletins (TSBs) are repair instructions that car manufacturers release when there is a recurring problem with a vehicle. TSBs often identify issues that were overlooked when a car was made, and they are typically released the year after it goes on the market or the year after it has been redesigned. TSBs are used to address a broad range of problems – from mechanical to cosmetic – and are intended for use by dealership service departments. Because TSBs provide standardized repair procedures, they save mechanics time when troubleshooting and fixing problems. For consumers, this can mean a car will spend less time in the shop and receive better quality repairs.

How are service bulletins different from recalls?

Service bulletins are often confused with recalls. Unlike a recall, a technical service bulletin does not address a safety or emissions issue. Manufacturers are not required to inform owners when they release a TSB; however, if an issue is widespread, the manufacturer may opt to notify customers. A TSB also differs from a recall because, unless your vehicle is under warranty, the dealership will usually charge you for the repair. Even if your warranty is still valid, the dealership won’t make the repair for free unless a mechanic verifies your car is affected by the issue addressed in the TSB

the buddmang

Fuel pressure has nothing to do with the heat soak issue occurring on the #3 and #4 injectors. If there was a problem with fuel pressure or the regulator...it would affect SIX cylinders. Not only one or two.

the buddmang

If you saying you're smarter than the tsb (thats been out since 02ish with ZERO revisions to the repair procedure) then you need to talk to chrysler about getting a job as an engineer...because evidently they have NOOOOO idea what theyre doing.....

77olds

rrich, you need to shut the f up about gum wrappers, I don't know who the hell said gum wrapper in the first place but you've been ranting on and on about it for 5 pages now, made a mention of it in every single post of yours.

A heat shield is not a gum wrapper.

i know you think you're clever with your little quips, but don't you realize that this entire forum is laughing at you?

SamSissine2

So, I would say this thread is getting ready to be closed since its a little off the beaten path...

rrich

How do you know it's only affecting #3 and 4 cylinders? You don't believe in test equipment - it's just your assumption it's those 2 and not others.
The way the OP described the missfire it sounded like it was more than just 2 cylinders.


How many 4.0's have been produced since '02?
Why hasn't it been a problem before?
Why is it in only the cold climates?
Why isn't it a popular problem in the warmer climates - like here in the desert - where we actually get heat?
Why, if it's such a common problem, why are there no updates, revisions or repeats on the '02 TSB?

If someone was experiencing the problem on a 95, why would he look at '02 TSB's?

You claimed the vapor problem was due to heat traveling up through the head to the injector. So how is putting gum wrappers on the outside of the injectors going to stop the heat coming from within?

You are the one that mixed up recalls with TSB's in previous posts - obviously you don't, or didn't, know the difference.

Check with a dealer to find out where the TSB's come from and how many are believable. Most dealers don't keep them, and if they do they rarely get looked at.
ALLDATA puts lots of emphasis on them so they don't have to show the diagnostic procedures.

TSB's are only suggestions - just like my suggestion of checking fuel pressure.

If you are not capable of checking fuel pressure (after all, it does involve fuel and requires the use of tools - you'll need an adult supervisor,) then do what you think will work.

But please stop trying to mislead others to satisfy your twisted ego. Find out what's going on before you continue to make a fool of yourself.

If the pressure was high enough during the hot start attempt, the fuel would no longer be vapor - on any cylinder not just the one you imagine.
What is the vapor pressure of hot gasoline? The pump must be higher than that to cause it to go back or remain as liquid. That's just basic physics.


Why do you think FI systems use higher pressure than carbs did?
Why do you think they put the pumps by the tank, instead if up front?
Why did jeep put the FPR "up front" instead of by the tank and pump?

rrich

Somewhere "back when" it was suggested parts house insulation or aluminum foil.
I stand corrected - not all gum wrappers or candy wrappers are made of aluminum foil.
Tinfoil would not be right either, since it's very hard to find.

gary s

I had this exact problem a couple of years ago towing in Florida.Left home here in Illinois no trouble till then.Stopped at a rest stop and when I left,bad running and thru code for #3. I had approx 65k on the Jeep, problem would clear after running a bit.Got to where we were going to stay for a couple of days so I bought plugs since it did say missfire.Was not towing for those days and it never happened again,so I didn't change them . Left to go further south and it started again. Finally got so bad it would not clear and drove about 45 miles to the next rest stop under 50mph on 5 cylinders. changed #3 plug everything was fine again until I got back to Illinois and it happened again. Jumped on to this site,someone told me about the tsb, got the insulator hose from the Jeep dealer and pulled off that leaf guard that was a recall for mine since it was delamating and looked to be funneling hot air right to #3. Problem never has happened again since and I have been towing in even hotter weather than I was in Florida. Never touched anything else in the fuel system. I have always wondered if the different gasoline formulas mandated by the epa have an effect also

RenixHeep

Totally. Older vehicles aren't designed to run properly with some of the **** they put in gasoline these days, I've heard alot of horror stories about it when I was in tech school. It pays to find a pure gasoline pump station if you can, near impossible out here in california sometimes.