Hi All, I hope someone can help me,

TJ Exec 3.5 Magna sedan, has just had a fuel filter replaced, and the engine is not idling corrently. I am aware of the re-learn procedure, but this car is not getting the opportunity to learn ecause it keeps experiencing die out. A foot on the throttle will keep it running, but it it cannot idle. Also im told, it feels like fuel starvation.

I am helping someone out here (person with the TJ), and as I know very little about fixing engines or their fuel supplies, I am stumped! The Tech Manual says to consult a MutII. At the moment this is not feasible. I am asking to see if this problem has been a common occurance and what was the solution??

All of the spark plugs/leads/battery connections and fuel lines have been checked and the pump is working fine.

Thanks for any help.

Michael.

When I changed mine it worked fine.
It's not leaking ?
Did you put it in right?
Did you connect the elec clip on the fuel pump under the rear seat properly?

ok - a lil more info on the situation thats happened:

the TJ magna, was apparently running roughly over the weekend - from what i understand in the typical third gen rattles/shakes in drive.

at this point - the car would start and run by itself

we disconnected the battery for 5mins or so and then reconnected again, set the Sedan and 3.5L options again - expecting it to be a little difficult for the first 5 or 10mins while it got its stuff together to learn how to idle again..
stalled out straight away, so on the next start, a little accel was required to keep it running.
slowly took foot off accel - stall
restart, flick aircon on - foot on pedal for 2mins or so, then slowly release... STALL...

so - turned ac off - restarted - keeping it at about 1500RPM or so.
while holding the accel constant, the revs kept hunting up and down - dropping down to 1000 at one point without taking my foot of the accel, and climbing to about 1700ish i guess. would drop down, then kick up high again, then low then higher then hold at the initial 1000 and rinse repeat!

had a look at all the vac pipes running all over the engine bay - none appear perrished or broken - all appear to have good solid connections to where they need to be.
Air filter - is a little dirty, but its still serviceable for the moment

car has 130xxx km on the clock - AFA we know, its never had a timing belt done (its been booked in for that to be replaced next monday)

fuel filter was replaced today before i got to the car after work, but it apparently made no difference.

when it does run - the exhaust sounds like a tractor!!!
car has oil - and trans fluid etc etc - no signs of emulsification (spelling?) on the oil cap - oil is clean / reasonably fresh too.

took the car for a lap around the block in the hope that it might help - when rolling to a stop (intersection etc) STALL..
when under light accel/part throttle its VERY rough/jumpy until about... 3000rpm, when it smoothes right out and suddenly there is power again.

can hear the fuel pump working away happily too.

hopefully my mega post hasnt been (too hard to read) and has helped a bit with a suggestion of what to check?

cheers

Still sounds to me that it might be the fuel pump.
Also might be an idea to check the distibutor cap, make sure all the plugs are fully on.
Could be injectors
Could be bad fuel
Spark plugs may be dying

Still sounds to me that it might be the fuel pump.
Also might be an idea to check the distibutor cap, make sure all the plugs are fully on.
Could be injectors
Could be bad fuel
Spark plugs may be dying

thanks for the reply (im taking over Michaels thread here - coz it was mine anyway! haha)

leads appeared to be on the dizzy - checked that
and made sure they where on good where they dissapear into the rocker covers - inc the middle rear one = burnt hands :S

he has a mate going around there that might be able to fix it tomorrow for him - hopefully....

Ok is the lack of power feeling like a mis-fire? A stutter while under load?

Does it rev cleanly in neutral?

Another thing to check would be a quick search of ISC (idle speed control), it could just be a coincidence that this mechanism has died.

make sure all the bolts around the intake plennium are tight, with gasket goo/good gaskets. if it is not an EXCELLENT seal, it will idle crap, stall, sound like a ski boat.

edit. the nuts under the fuel rail (12mm by memory) are a prick to do without taking the rail off. you need a flexable 1/4 inch handle with a short 12mm socket.

Ok is the lack of power feeling like a mis-fire? A stutter while under load?

Does it rev cleanly in neutral?

Another thing to check would be a quick search of ISC (idle speed control), it could just be a coincidence that this mechanism has died.

Dammit!!! I just thought of that and you beat me to it

Ok is the lack of power feeling like a mis-fire? A stutter while under load?

Does it rev cleanly in neutral?

Another thing to check would be a quick search of ISC (idle speed control), it could just be a coincidence that this mechanism has died.

yeah it revs cleaner in neutral - wouldnt say its smooth and clean, but its not horridly rough.

it does feel like its stuttering when under load...

Last time my car stuttered under load, sounded like a tractor, but revved cleanly above roughly 3K and a lot better in neutral....turned out to be the spark plug leads.......

I done a good service on the car including new Top Gun leads, they broke down after 1000km so they were the last thing I checked...

Replaced rotor button, distributor cap, fuel filter, checked for air leaks......

p.s buy Bosch leads if it is the issue......

problem has been solved!

turned out to be, blocked injectors!

must have happened (or worsened as it seems) when the fuel filter was changed - and dilodged a lot of crud up into the fuel rail.

they have been cleaned (on car from what i can gather) and the car runs like a dream.

cost 300.00 inc labour - im thinking that it includes the labour for a couple of hours to fault find then to fix.

to resurect this thread (and save making a new one!)

the problem is coming back on the above mentioned car for this thread.

the car still runs and drives and starts and idles and the like, but under decelleration / coasting along, the driver has descibed the feeling as the car is shaking.

went out on a mini meet tonight, and it wasnt playing up until after about... 150ish kms, and it started it.
under constant accel / cruising the issue is not there.

since the begining of the week, the car has had 3 bottles of nulon/ wynns injector cleaner thru the tank (i get the impression that put one bottle in, drive for a while... another bottle... drive again then another bottle without running the tank low enough to warrent a refuel)
he said that when he does run injector cleaner thru - the shakes / shudders are not present...

also, on a side note;
at idle tonight, the car was sounding like it was hunting and missfiring a bit too.
put a leaf up against (not covering - in the air flow line away from the tip) the exhaust, and it would get sucked back to the exhaust tip a few times - wasnt a repetative pattern pattern either - very random: not get sucked back for a few seconds then pulled back 4 or more times in a row.
not sure if the side note helps or hinders for this situation.