...up to @ 2k rpm then idle; up to @2k as nauseum; s..ty kitty
#1
07-29-2014, 04:41 PM
...up to @ 2k rpm then idle; up to @2k as nauseum; s..ty kitty
Well, folks. When she runs, she runs well. Although she's not very fast off the line. Highway and back roads are just fine...if you can get there. 1986 XJS base coupe 5.3 v12
I'm going to have to figure where to post performance issues. I presume this may not be the right place?
After running nicely for any length of time, usually after the choke is off, she acts like the fuel is shut off. The engine idles but dies off about 1600rpm or so; when you let off the accelerator it drops to idle speed. As soon as you start to raise the rpms again it drops off. So at this point, even if you floor it, the engine will climb up to just below 2k rpm and drop off...if you hold it to the floor it just cycles up to @ 2k then to idle. Up to 2k then idle...and so on, until you give up. Give it a couple of minutes of idle, then it will run okay until some undetermined time in the future, like after a couple of hours sitting in a restaurant.
I'm tired of eating humble pie. Great looking car on the side of the road....Hmph!
I'm going to have to figure where to post performance issues. I presume this may not be the right place?
After running nicely for any length of time, usually after the choke is off, she acts like the fuel is shut off. The engine idles but dies off about 1600rpm or so; when you let off the accelerator it drops to idle speed. As soon as you start to raise the rpms again it drops off. So at this point, even if you floor it, the engine will climb up to just below 2k rpm and drop off...if you hold it to the floor it just cycles up to @ 2k then to idle. Up to 2k then idle...and so on, until you give up. Give it a couple of minutes of idle, then it will run okay until some undetermined time in the future, like after a couple of hours sitting in a restaurant.
I'm tired of eating humble pie. Great looking car on the side of the road....Hmph!
Last edited by spindrifter; 08-01-2014 at 11:15 PM. Reason: Add model
#2
08-01-2014, 11:14 PM
#3
08-02-2014, 05:33 AM
Couple of quick thoughts in some sort of order:
Fuel filter is past the use by date.
Fuel pump is OLD, and LAZY.
The TPS is getting flaky.
The exhaust is clogged, and/or the Cats are knackered.
The spark plugs are OLD.
The AAV is not shutting off 100%.
The throttle cross roads are out of adjustment/sync.
The fuel tank venting fiasco is playing up, pop the filler cap and retry.
The air filters are clogged.
All that maze of emissions plumbing is now OLD, and possibly back feeding up its own backside, and reeking havoc. If emission testing is still done in your area, removal is not an option, if not, remove it or plug it off.
Fuel filter is past the use by date.
Fuel pump is OLD, and LAZY.
The TPS is getting flaky.
The exhaust is clogged, and/or the Cats are knackered.
The spark plugs are OLD.
The AAV is not shutting off 100%.
The throttle cross roads are out of adjustment/sync.
The fuel tank venting fiasco is playing up, pop the filler cap and retry.
The air filters are clogged.
All that maze of emissions plumbing is now OLD, and possibly back feeding up its own backside, and reeking havoc. If emission testing is still done in your area, removal is not an option, if not, remove it or plug it off.
#4
08-02-2014, 05:36 AM