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Unread 07-05-2013, 11:47 AM   #61
Siva283
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Have you checked mechanical time yet. Yes the sensors can be tested. THe procedure is in the FSM. I just saw a link to it earlier this morning but forgot to save it. I am sure someone posting in here has it though.

__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 12:04 PM   #62
laybackman
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OK, your problem seems to be heat related.

You have had some high temps lately haven't you? I forgot if you mentioned it or not but are you still running the clutch fan? Does the engine temps get kind of high on these runs you are making? Is it worse at slow speeds faster than at highway speeds?

Popping back through the throttle body and general lack of power could also be vapor lock from excessive heat in the engine compartment.

Wrap your fuel lines in the engine compartment with insulation and aluminum foil to see if that makes a difference.

What does your air filter look like? is it clean?
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Unread 07-05-2013, 12:49 PM   #63
C2tuck
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Yes...checked timing and it's steady at 8 degrees.

It's not getting hot at all. Generally runs at 180. It only happens at highway speeds and only after more than 10 miles. Air filter is brand new and clean. Gonna change the fuel filter but don't really think that is the issue...hopefully I'm wrong...
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Unread 07-05-2013, 01:08 PM   #64
laybackman
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Quote:
Originally Posted by C2tuck View Post
Yes...checked timing and it's steady at 8 degrees.

It's not getting hot at all. Generally runs at 180. It only happens at highway speeds and only after more than 10 miles. Air filter is brand new and clean. Gonna change the fuel filter but don't really think that is the issue...hopefully I'm wrong...
Under the hood it gets hotter than normal in the hot weather though and that is where your fuel system is. Pop the hood so the safety catch has it and drive it. See if that stops it from running like crap. BE CAREFUL if you do that add a safety strap of some sort.

In 1987 I bought a brand new Chevrolet El Camino SS. For the first two years that I bought it I had to change the fuel filter on it every 2,500 miles or so. It would bog, and or begin to stall while running down the road. Did that until I had about 20k on it. It never backfired though.
And no, the stealership had no idea what the problem was. They got one shot at fixing it and then I never brought it back to them.
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Chicks dig me.....Fish fear me

Getting older, I have developed some special skills. I have the ability to cough, sneeze, fart and pee at the same time.

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Unread 07-05-2013, 01:51 PM   #65
Siva283
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Vapor lock in MPFI. I have never heard of a vehicle doing that. Are you sure there isnt carbon build up in the cylinders. When that gets hot it could be causing it to fire at the wrong times just from heat build up in the carbon deposits.
__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 02:16 PM   #66
C2tuck
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No I'm not sure. But I really don't want to do too much as I'm a lout to start tearing down my 4.0 and send it off to the machine shop. Hopefully have that in in a few months.
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Unread 07-05-2013, 02:43 PM   #67
laybackman
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Quote:
Originally Posted by Siva283 View Post
Vapor lock in MPFI. I have never heard of a vehicle doing that. Are you sure there isnt carbon build up in the cylinders. When that gets hot it could be causing it to fire at the wrong times just from heat build up in the carbon deposits.
If that fuel is too hot when it hits those injectors I think vapor lock is a distinct possibility even for MPFI. Or at least he would run real lean since the hot fuel has much less density.

But if he is getting pre-ignition from hot carbon spots the OP can just dribble water down the throttle body while revving the engine and the steam made will boil off the carbon deposits pronto....just like a cracked head gasket would do to the plugs valves top of the piston etc. maybe that is that he should try next.

But his symptoms seem to be heat related. What do you think is the problem if it isn't carbon build up?

Maybe the coil/ignition module is getting too hot? The OP does live in Texas.
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Unread 07-05-2013, 05:14 PM   #68
Siva283
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Quote:
Originally Posted by laybackman View Post

If that fuel is too hot when it hits those injectors I think vapor lock is a distinct possibility even for MPFI. Or at least he would run real lean since the hot fuel has much less density.

But if he is getting pre-ignition from hot carbon spots the OP can just dribble water down the throttle body while revving the engine and the steam made will boil off the carbon deposits pronto....just like a cracked head gasket would do to the plugs valves top of the piston etc. maybe that is that he should try next.

But his symptoms seem to be heat related. What do you think is the problem if it isn't carbon build up?

Maybe the coil/ignition module is getting too hot? The OP does live in Texas.
I always thought the pressure 31psi in oir jeeps kept them from vapor locking. I would try the water trick or seafoam. Water is free and does a great job though. The coil is a good thought when they heat up they can short out. We do agree its heat related. Running lean from hot fuel could be a good possibility too since fuel is less dense.

Op do you have this problem after the sun goes down as well or just during the day.

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__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 05:19 PM   #69
Siva283
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I apoligize if this has been answered already I am on my phone and don't remember all the posts. Jave you checked the crank sensor? Also the cam sensor it can cause the ignition timing to becone erratic and fire the plugs at the wrong time. Is the dizzy tight? Is there any play at the rotor. Again I apologize if these have been answered already?

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__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 05:29 PM   #70
Siva283
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Ok broke out the iPad so I could read easier. I think you should try the water trick. Don't use sea foam if your not worried about the engine long term. The more I think about the more it sounds like the pick up sensor in the dizzy or the ignition coil. Both of those sensor will work on the 4.0 so you can use them as spares if you like

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__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 05:31 PM   #71
C2tuck
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No...everything is tight as far as the dizzy and the rotor and cap. Already replaced them with no change. Yes it happens at night too. Coming back from the movies the girls were cold...it was fairly cool out that night and it did it just the same. I mentioned the cam and crank sensors in this thread and no one thought that was relevant. Is there a way to check them or are they cheap as I don't want to really throw parts at this thing. No one has ever had this problem before??

I'll try the water thing when I get home this evening.
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Unread 07-05-2013, 05:46 PM   #72
C2tuck
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I already tried the I coil and it didn't change anything. So I put the old one back on and am going to go get my $50 back. Where is the pick up sensor located and how much if a pain is that to change?
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Unread 07-05-2013, 05:46 PM   #73
Siva283
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Quote:
Originally Posted by C2tuck
No...everything is tight as far as the dizzy and the rotor and cap. Already replaced them with no change. Yes it happens at night too. Coming back from the movies the girls were cold...it was fairly cool out that night and it did it just the same. I mentioned the cam and crank sensors in this thread and no one thought that was relevant. Is there a way to check them or are they cheap as I don't want to really throw parts at this thing. No one has ever had this problem before??

I'll try the water thing when I get home this evening.
There is a way to check them. It's in the fsm you will need a multimeter. There is a link on here somewhere to the fsm but I don't have it on here. A quick search could find it or hopefully someone on here will post it. I am really thinking the pick up the coil should cause a miss not a backfire when it starts to go.

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__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
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Unread 07-05-2013, 05:48 PM   #74
Siva283
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Quote:
Originally Posted by C2tuck
I already tried the I coil and it didn't change anything. So I put the old one back on and am going to go get my $50 back. Where is the pick up sensor located and how much if a pain is that to change?
The pick up is I side the dizzy take the cap and rotor off and it's that flat plastic piece with the connector coming out off it. It just pops out.

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__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
Siva283 is offline   Reply With Quote
Unread 07-06-2013, 07:19 AM   #75
laybackman
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Quote:
Originally Posted by Siva283 View Post
I always thought the pressure 31psi in oir jeeps kept them from vapor locking. I would try the water trick or seafoam. Water is free and does a great job though. The coil is a good thought when they heat up they can short out. We do agree its heat related. Running lean from hot fuel could be a good possibility too since fuel is less dense.

Op do you have this problem after the sun goes down as well or just during the day.

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Good morning! YOU ARE CORRECT! Breakfast and the beginning of the day is good for us older folks!! With the kind of pressure MPFI requires the gas is under some high pressure so the boiling point of gas is way higher than anything that can be produced in an engine compartment.
Once the fuel is injected into the cylinders it gets fired and then it is nothing but exhaust gas.

BUT I still think heat does have something with this problem. I wonder what would happen if the OP pulled his hood or pop it partially open like I mentioned earlier?????

IIRC the one thing the OP didn't do was check for stored codes. Didn't one of us tell him about the 'key thing' for reading any DTC's? OR did he do so and I freakin' forgot already......I gotta start drinking again...
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Getting older, I have developed some special skills. I have the ability to cough, sneeze, fart and pee at the same time.

"If we cannot afford to take care of Veterans, then we should stop making them."
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