I've done the obvious stuff, dry gas, new plugs, checked codes (none), still runs rough. Idles fair, runs at road speeds well until acceleration is needed. Upon accelaration, it'll wheeze and buck a bit internally. New plugs seemed to help at first, but now it is back (though not nearly as bad). I'm thinking bad gas, let it run its course and refill. A couple of guys at Advance said that ethanol was causing all sorts of problems like this.
So, any ideas? New fuel filter?
I would agree with the gas since it spoils in 2 weeks. I would suggest maybe an octane booster, new plug wires, and as you said a fuel filter. Never hurts to cover all of the easy things first.
If all that fails I'd say fuel pump. You can get a cheap pressure gauge to check fuel pressure. Someone on the board should know what it's supposed to be.
Keep in mind with that driving rain we just had water can get into a lot of places. I didn't drive anywhere during that storm but after two days of sitting my trucks brakes were real grabby until the rotors dried off.
I've heard with this ethanol to use fuel injector cleaner every once and awhile.....
Also octane booster.
I've heard with this ethanol to use fuel injector cleaner every once and awhile.....
Also octane booster.
that is a good idea because of the potential carbon build up...
i would suggest using some 93 octane with some seafoam fuel cleaner....i do that usualy every 4 tanks....bout once a month
i haven't had any ill-effects from the new gas - and our drivetrain is pretty similar. new plugs....which ones did you go with? the 4.0 is pretty finicky when it comes to plugs. and the codes - how did you check for them? did you do the self-diagnostic test or did you use a reader? the self test won't give you all the codes...just some of them. and just fyi...the CEL (check engine light) only comes on with emissions-related issues. sometimes there are other issues going on that won't trigger the CEL but will still have your engine running like crap. i'm not sure how an octane booster will help things since the problem really shouldn't be based upon the octane of gas...but an additive to the fuel that cleans/drys things could possibly help.
chris
p.s. your fuel filter is connected to your fuel pump inside the tank - not usually something that has issues so early in your tj's life unless you've gotten debris dropped into the tank. can't rule it out entirely but not as common as other stuff. oh, and the manual specifically says 87 octane for the 4.0 as well - not sure about the later 2.4L though. if someone needed to use 93 octane to have the engine run properly then i'd venture to say something else must be wrong.
i didnt mean to run 93 regularly but to use it to make the engine run rich and help clean it out every now and then
What's it like changing wires with this spark plug rail? Does THAT ever need replacing? I did the Seafoam on Sunday, so it is still working. I'll probably try to let this tank run out before any more parts are changed.
BTW, I also changed my Oil Pressure Sending Unit...easy, but killed my back leaning over the TJ lifted...had to use an adjustable wrench. Someone said there's a special socket...true?
Bosch +4 Platinums
And, who was it who could run all the codes (in Dover)?
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What's it like changing wires with this spark plug rail? Does THAT ever need replacing? I did the Seafoam on Sunday, so it is still working. I'll probably try to let this tank run out before any more parts are changed.
BTW, I also changed my Oil Pressure Sending Unit...easy, but killed my back leaning over the TJ lifted...had to use an adjustable wrench. Someone said there's a special socket...true?
Bosch +4 Platinums
And, who was it who could run all the codes (in Dover)?
no wires to change with the spark rail
and in theory the rail should never need replacing
yes there is a special socket for o2 sensors and sending units
u can get them at napa autozone just about any parts store
iirc sears has them as well
And, who was it who could run all the codes (in Dover)?
I believe that Tony can do it at his shop, do not quote me on that though.
Its the same as a spark plug socket so i just cut the slot in one of mine to use for my o2 sensors.
Speaking of 02 sensors...could THAT be an issue? It is near the Cat right?
make sure you dont have an exhaust manifold leak anywhere.i recently worked on a tj that would rungood the all of a sudden run like crap for a while then go back to running normal.i did the plugs,wires cap,rotor.02 sensors and feul filters till i found out it was the exhaust.
Speaking of 02 sensors...could THAT be an issue? It is near the Cat right?
there should be four of them iirc on ur 02
there is 4 on my 03
possible but would throw a code if it were a o2 sensors
Simple codes on my trip meter?
Where are 02 sensors?
yes
but remember there are two wyas ti check the codes
one way is with the key on-off trick
the other way just checks the dash
two sensors in the exhaust manifold b/4 the pre cats and two just after the pre cats
and it could be the cat itself
and it could be the cat itself
if it were the front two
they would throw a code
im dealing with that now
not the back one tho
its not monitored iirc
there r 3 cats on 00 tj's and up
I have the actron scanner the one you get at auto zone and I also have access to a $3000 dollar or so machine that will pull all codes to include abs and tranny codes. i will have this machine this week so if you want me to check your codes shoot me a pm and we can set up a time belive it or not I am acttually pretty business right now but have vacation all next week.
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