N20jeep

To much fuel pressure is bad.

You will end up running rich and having other driveability issues. And you can damage the injector itself

RenixHeep

Learn something new everyday

rrich

Of course you always tested the pressure when it was hot and wouldn't start, duplicating the problem.
Testing it when its not vaporized means nothing.

Like I've said many times before - if it works for you do it! If using gum wrappers is your kind of fix do it! And be sure to brag about it so everyone knows!

77olds

Testing the pressure while the fuel is vaporized means nothing, either. You're not going to get an accurate reading of fuel pressure even if the fuel pump and regulator are working 100% flawlessly.

Dude, just admit you're wrong. Be a man.

the buddmang

Im glad someone besides me has some sense. Some people just wont ever get it though.

77olds

I'm sure he knows he's wrong, he just has too much pride to admit it and bow out.

It's not a pissing contest, I don't really CARE if he's wrong and I'm right, I just don't want this guy going around giving bad advice to people. I know how it is to be on a tight budget and rely on my vehicle every day, and then be given bad advice by a self-proclaimed "expert" which makes the situation that much worse.

Sure, check the fuel pressure if you want. But installing a heat shield or otherwise protecting the injectors from heat WILL cure the problem.

rrich

"""""Testing the pressure while the fuel is vaporized means nothing, either. You're not going to get an accurate reading of fuel pressure even if the fuel pump and regulator are working 100% flawlessly."""""

What would suddenly make the pressure gauge to read accurately? It will read whatever pressure is in the line. The gauge itself doesn't turn to mush.

Yes, it won't read to specs - it will be low - because the pressure is low - while it's still vapor! Testing it later when the vapor is gone it will read normal.
Like many intermittent things - You have to test it while it's acting up.


That's the point exactly - if something is inhibiting the pressure it will vaporize! Why low? Because either the pump or FPR is weak. If they were able to develop the correct pressure, the fuel will not vaporize!
Where is the FPR? Isn't it right on top of the engine where it gets hot?

Tight budget? How does using a pressure gauge cost anything when so many parts housed loan them for free?

Dependable - if the problem still exists after your internet witchcraft, does that make it dependable?

Foil is just a temporary patch - it will get worse eventually.

BUT DO I CARE WHAT THE FOOLS THINK?

"It can't be that - because I don't want it to be that."

N20jeep

I have told you I have checked pressure among other things. I know how to duplicate the problem so checking pressure while acting up is easy.

But you seem to ignore that

Parsnip

How about this crazy idea- he actually TRIES everything recommended thus far and see what happens? If the foil.in fact doesnt work, then ok...really no need to argue, lets just wait for the op to let us know what works

DFlintstone

Myself, I might deal with the TPS code first. Change it, then take it from there if there is still a problem.

77olds

I'm telling you for the LAST time. A bad fuel pump is NOT THE ISSUE RELATED TO THE VAPORIZATION OF FUEL WITHIN THE INJECTORS.

If you can't get that through your thick skull, then YOU my friend have a sad, sad problem.

Posting various insulting quotes at the end of each of your posts is childish, as well.

rrich

""""Posting various insulting quotes at the end of each of your posts is childish, as well. """
You mean like this?

OK, tell me in all your infinite wisdom - I just got back from Palm Desert - it was 105 degrees there today. It's cold here now, only 95.
The other day it was 112 in Palm desert. I did several short stops - nary a burp from it.
A few days ago when it was over 115 I was in one of my Rubicons - no problem then either.
Neither of them have foil insulation - never did - nor do they have gum wrappers or shewing gum fixes.

In fact none of my 4.0's do - 5 in all now, and none of my previous ones did either.

One previous Cherokee I sold a while ago had the heat problem - that's one reason i got it cheap. I left a gauge connected to it and drove it. I got it hot and parked it - before I started it but after I cycled the key the pressure was around 10 and holding. When I cranked it the pressure slowly came up and it started - popping and misfiring a moment. Pressure was fine after that.
A new Fuel pressure regulator cured it. As I remember it cost about $30.

Now for you - why does it only happen in cold climates when it gets warm?
Why is it only when the temp is low - around 80 degrees?
Why aren't there thousands of complaints about it?
Why isn't it a problem where it's warm?

It's not unlike years ago - vehicles that only made short trips or were seldom used - like motorhomes and campers - would experience fuel pump failure once it got fully warm.
They always seemed to fail going up hills in warm weather. Many vacations were ruined sitting on the side of road instead of having fun.

The diaphragm in the fuel pump was rubber and failed from the heat. A FRP uses a similar diaphragm.

But - there's always the possibility of a weak pump too. The FPR does not increase pressure it can only reduce the applied pressure.
If the pressure was low from the pump to start with. system pressure will be low. That's why i suggested measuring pressure on both side of the FPR - while it was acting up!

But no, don't use logic - it's not allowed on this board. - just blindly chew away.

77olds

rrich, I would appreciate it if you would very carefully read the following:

I can make a million short stops in my XJ, and the problem does not occur. The problem DOES occur when I've left it parked for 10 to 20 minutes.

Without airflow and the cooling system operating, the temperature of the engine will INCREASE after shut down. Go ahead and try it - get your Jeep up to operating temp, get it nice and hot. Then, go park her somewhere and shut her down. Watch the gauge climb.

There comes a point where the temperature has gotten has hot as it's going to get. That's the point, roughly, in which the heat soak affects the fuel injectors.

So if you're making a ton of short stops, the engine bay probably isn't getting hot enough during it's shut off period for the problem to occur. Try going for a nice long drive, get her really hot, then park it for 15 minutes. Go back out and crank her up.

Mine does it in 80* and up weather. Sometimes 70* and up if I've really had the engine working.

Why aren't there thousands of complaints? THERE ARE! THAT'S WHY CHRYSLER ISSUED A TECHNICAL SERVICE BULLETIN!





From this point forward, I want you to consider something.

You are basically saying that all of the Chrysler engineers are wrong. You're saying that everyone who has experienced and conquered the heat soak problem is wrong.

You're saying that somehow, those who have shielded their injectors, have cured their FUEL PUMP or REGULATOR problem.

I will say this to you one last time, then I am done because this is really making me lose hope for all humanity.


YOU

ARE

WRONG.

Suck it up. Man up. Deal with it. You don't know what you're talking about, you're taking a simple problem and complicating it to the max, and I swear you've driven me insane with your constant "bubble gum wrapper" phrase which has NOTHING TO DO WITH ANYTHING since it's a terrible analogy.

Talk to people who build race cars about how heat shields are important.

N20jeep

Don't forget, he also assumes that he is the only person capable of reading a fuel pressure gauge.


And his one problem he had with an xj means that everyone elses problem is caused by the same thing

rrich

77 olds - """""Mine does it in 80* and up weather. Sometimes 70* and up if I've really had the engine working."""""So yours STILL does it even after you wrapped it?
Good going! YET YOU ARE AN EXPERT! Im surprised you even admit it!

I made several stops - between 5 to 30 minutes in the heat - most about 15 minutes -- not even a burp.

Why is it some of you resist using a pressure gauge?
Is it just too technical?
Afraid it my show the real problem and cost a little?
All I've ever suggested was CHECK THE PRESSURES!

""""Don't forget, he also assumes that he is the only person capable of reading a fuel pressure gauge."""""

If you'd actually used it instead of make believe you'd understand how to read it yourself. It's not rocket science.

But go ahead believe what you want.

It's a good thing I never asked about cranking vacuum as applied to the FPR- that also affects rail pressure. I'm sure that would drive some of you to suicide!


TSB's are submitted by service writers and technicians, as well as the general public. Not written or condoned by engineers.

Proof they are often wrong - there has been several TSB's issued that say to clear the DEEP PCM MEMORY (on OBDII - lest a fool thinks it applies to RENIX) by touching the cables together and stepping on the brake pedal. But there have also been several more TSB's saying that does not clear the DEEP MEMORY - it only clears the surface memory - clears codes is all.
If you had a scanner capable of reading the memory, not just a cheapie code reader - you'd see the deep memory is still there.

TSB's are not always correct, and often contradictory.

All some of you have done is shown that you haven't a clue about anything and are not willing to THINK.

We know what you do with gum wrappers and duct tape - What do you do with Pop Tops?