- Location
- So.Cal. Low Desert
So I've searched on & off for a few days with not much luck in finding a similar issue.
So recently past 6 or 8 mons. I've been experiencing intermittent idle issues where if I'm sitting at a stop light or poking along on a trail or idling while airing up the XJ starts to 'load up/or starve'... the idle will start at 800/900 RPM & slowly start to get lower & start to run rough, sometimes I can hop in it & gently feather the throttle and get the RPMs to rise then say above 2500 RPM it'll smooth out and I can bleep the throttle to blow it out... sometimes it'll stumble & struggle to stay running... hence the need to 'feather' it.
It's very random, one ride to work might be fine or a longer trail ride it might happen multiple times, distance doesn't matter. I can get on the freeway & it'll run like a scalded cat ! A couple times that I've 'cleaned it out or blew it out' I got a sulfur smell... it's not like there is a lag on acceleration it just won't go... then I 'feather it" and it'll slowly get going, frustrating at a stop light...
The XJ has about 165K on it & I had the head rebuilt about 10K to 14K miles (about 2.5 yrs. ago) ago replacing the cap, rotor, plugs, wires & such. The Cat. is a Magnaflow replaced approx. 50K ago... there is no rattling.
After the latest time it threw some fuel codes... Random mis-fire & cylinders 1,3 & 4 misfire...
The fuels system is unmolested so far... it'll pressure up in a second or two..
Just the other day I checked fuel press. and it was at between 46 & 48 psi idling with no hint of it loading up. There was a flutter on the gauge needle as mentioned, maybe the gauge isn't the best of quality or the psi was truly fluctuating a bit ?? I was hoping it would act up while the gauge was on it.
I'd really just prefer the damn thing fail so I could figure it out and not have some random idling issue...
-It'll start pretty quickly...
-Semi-new cap & rotor, plugs & wires...
-Magnaflow Cat. with approx. 50K on it...
-Rebuilt head & such 10K to 14K ago...
-O.E. fuel pump...
I just don't know to look to the fuel side or the ignition side... OR ! a sensor somewhere...
OH !! one other random odd idle issue is on occasion it wants to idle say in park at 1500 RPM... I bleep the throttle & it returns to the 800/900 range.
Sorry for the length I just wanted to paint as clear of a picture as I could...
As always any thoughts or advice is appreciated... while I'm OK with a wrench I'm by nooo means a mechanic...
Thanks...
Curt
So recently past 6 or 8 mons. I've been experiencing intermittent idle issues where if I'm sitting at a stop light or poking along on a trail or idling while airing up the XJ starts to 'load up/or starve'... the idle will start at 800/900 RPM & slowly start to get lower & start to run rough, sometimes I can hop in it & gently feather the throttle and get the RPMs to rise then say above 2500 RPM it'll smooth out and I can bleep the throttle to blow it out... sometimes it'll stumble & struggle to stay running... hence the need to 'feather' it.
It's very random, one ride to work might be fine or a longer trail ride it might happen multiple times, distance doesn't matter. I can get on the freeway & it'll run like a scalded cat ! A couple times that I've 'cleaned it out or blew it out' I got a sulfur smell... it's not like there is a lag on acceleration it just won't go... then I 'feather it" and it'll slowly get going, frustrating at a stop light...
The XJ has about 165K on it & I had the head rebuilt about 10K to 14K miles (about 2.5 yrs. ago) ago replacing the cap, rotor, plugs, wires & such. The Cat. is a Magnaflow replaced approx. 50K ago... there is no rattling.
After the latest time it threw some fuel codes... Random mis-fire & cylinders 1,3 & 4 misfire...
The fuels system is unmolested so far... it'll pressure up in a second or two..
Just the other day I checked fuel press. and it was at between 46 & 48 psi idling with no hint of it loading up. There was a flutter on the gauge needle as mentioned, maybe the gauge isn't the best of quality or the psi was truly fluctuating a bit ?? I was hoping it would act up while the gauge was on it.
I'd really just prefer the damn thing fail so I could figure it out and not have some random idling issue...
-It'll start pretty quickly...
-Semi-new cap & rotor, plugs & wires...
-Magnaflow Cat. with approx. 50K on it...
-Rebuilt head & such 10K to 14K ago...
-O.E. fuel pump...
I just don't know to look to the fuel side or the ignition side... OR ! a sensor somewhere...
OH !! one other random odd idle issue is on occasion it wants to idle say in park at 1500 RPM... I bleep the throttle & it returns to the 800/900 range.
Sorry for the length I just wanted to paint as clear of a picture as I could...
As always any thoughts or advice is appreciated... while I'm OK with a wrench I'm by nooo means a mechanic...
Thanks...
Curt