car cranks fine, drives off fine. get out the driveway and give a little gas, she (sputters) may be the closest word for it, but only for a second. if i back off the gas it will slowly climb in accelaration with no wierd sounds. but once the gas is supplied to move her on quickly here it comes again.
once i drove the car with out the filters and filter covers off and it gave me this sound, but everything is in tact. any clue u guys?????

 

Could not remember what car/engine you got, found the other post, and I assume by "thermostats", and "still running hot", it is a V12????.

I would be suspect of the TPS (throttle position sensor), under the throttle capstan. Old age is now seeing these gettiing hissy, and that will give the symptoms you are describing.

Incorrect setting of the 2 throttle cross rods will also cause grief.

Fuel pressure issues, either the filter is overdue for change, and/or the pump is getting tired, causing a "lean fuel" issue, will give a splutter, as more is required and cannot be delivered.

USA market car, maybe many other items that I leave to those guys in that area.

 

i would agree with TPS issues.

if your giving it more air and its bogging out, then its not getting fuel.

i would suggest pulling the TPS apart and checking the condition of the resistence strips.

 

where is this TPS Lcated? How to remove and inspect?

 

Qgregg,

You're getting good advice here but the guys are having to trawl your previous posts to find your vehicle details.

Please add vehicle details to your Signature to help others to give relevant advice. Go to the User ID button on the left of the top menu bar, then Settings & Options under Your Control Panel. Select Edit Signature and enter the details.

Graham

 

i thought the engine info was on my profile under my name so sorry guys.

 

OK, listen up, I sometimes assume toooooo much, so if I confuse you, yell out, it will be fixed.

At the rear of the engine, dead centre, is the alloy wheel thingy that the gas cable wraps around, found it, good.

Under that assembly is an electronic device, that is a potentiometer, and that is the TPS.

Inspection, well NAH.

Testing, YES.

You will need a digital volt meter (DCM).

Now my memory, my car is TOTALLY rewired, and an XJ40 TPS is used, so the colours are different,

You will need to probe (push the pointy end thru the insulation, NOT your finger), of the "Red" and "Yellow" wire of the TPS loom, either coloured probe, it matters not. Most do it AT the 3 pin plug, which is about 4" away from the TPS.

Set the meter to "V DC", at a scale close to 12V, and turn the Ign ON, dont start the engine, just Ign ON.

At the idle position you are looking for close to 0.32-0.36v (do not stress too much if that is not the reading you get for now, it can be adjusted later IF the TPS tests OK). Slowly open the throttle and note the steady rise in the digits, WATCH CAREFULLY, as any fluctuating digit movements (as in up and down) means a flaky TPS. Slow and steady is required as most DCM's have a buffering for the display, so do it a few times and get the feel, it is NOT hard, just take your time.

Turn OFF the Ign when finished.

The TPS is what basically tells the ECU what fueling settings to use, so a flaky signal confuses the ECU, and all sorts of dramas unfold. It is ONE of the prime fueling sensors.

 

will check after work 2 day.

 

ok forgot to mention that i did find a hose that had come loose, that i put back yesterday, still ran rough after connecting so i did'nt think it fixed the problem. now today @ lunch i got down on it and zero puttering.
running good, maybe it took a little while for the gas air mix to straighten out. the hose is one of the three air hoses that come up under or beside the power steering pump i think two og the hoses connect on top of the block beside the air filter cover. the other was loose.

 

Those hoses sound like the fuel tank vent hoses from the charcoal cannister in the LH guard opening, forget exactly, dont have them on mine anymore.

No sputtering at lunch, THE CAR WAS HUNGRY TOO, haha.

Always keep in mind that ALL Jags are female, think about it.

That hose may have been a vac leak, and by fiting it you obviously plugged that, and some gremlin has now gone AWOL.

See how it goes for the next trip, but I do suggest testing that TPS, just for knowledge, as old age is simply rushing up on all these electrical items now, regardless of the mileage the car has done.

 

the TPS can be easily inspected by removing the 3 screws, and checking the resistance strips, assuming it fails testing.