Hey I have a 1991 Jaguar xj6 base and I have this fuel fail 89 code and engine is running rough sounds like a tractor lol. I have replaced the purge valve but no difference. Unsure what the cause could be. Maybe an injector?

 

Hi Michael, can you give us some more to go on? Is it constant, or cold / warm? My first suspicion would be a vacuum leak. There aren't a lot of vacuum lines but what is there is pretty well hidden. Mostly they are under the front of the intake, but if you have egr valve it could be in that circuit too.

 

Constant. I uploaded some photos if that helps. Egr “seems” ok.

 

There are a lot of things it could be and fuel may be one of them. If its making a lot of noise try using a chunk of heater hose as a stethoscope to try to pinpoint the origin. That would go a long way to narrowing your search. You can also try using the old carb-cleaner-test. With the car running CAREFULLY spray the cleaner over intake and vacuum lines the to see what will affect the running either good or bad. Or If the car has been sitting you may just need some fresh gas and a clean out of the intake parts. Good luck!

 

I am a bit suspicious about the very clean cam cover. Has somebody been washing down the engine?
Those plug lead grommets are not waterproof. They do have a breather hole
Check to see if you have any water down the plug holes.
I ran across this in an XJ40, and it was flooded in a couple of the plug valleys but still ran roughly. The owner had washed it.
Jaguar have a technical service bulletin about not washing these engine bays primarily based on possibly creating electrical problems but also affecting other parts.

 

No washing was done to the engine bay just a wipe down. Still dealing with a rough idle pretty much every component was replaced. To do with ignition except distributor, ignition amplifier. Could a throttle body cause this. Forgot to mention I had a shop clean the throttle body. They had disassembled the throttle and shortly after this the car started to idle rough.

 

I seen the vapor canister can be an issue for this code but unsure . Anything helps!

 

Could they have gummed up the throttle position sensor? Jaguar brilliantly mounted it at the bottom so everything would get into it. Check for the throttle plate And sensor both to be set right? There was a thread about the TPS getting oil in it, and to drill a small drain hole in the bottom of it.

 

how do I know if the throttle has been set right? I have a replacement tps to throw in later today.

 

The jag manual says there should be a .002" gap between the butterfly valve and the side of the body. I've found that thickness is about the same as the old thermal style receipt paper. Regular receipt paper is about .005 as I recall. If I remember correctly, once the gap is set, then you loosen the TPS to where it just bottoms with the throttle closed. You can also test the TPS for correct resistances throughout its range. I don't have that info at hand at the moment, but it should be a smooth movement as you open the throttle. I would certainly check for air leaks and hoses off in that area before disassembly. Brake clean works well.
I'm looking forward to being corrected.

 

I don’t like to let people work on my car but I had no option as I was packed with work and no time to work on it. I called up the guy that cleaned the the throttle and said he had removed the tps sensor and cleaned around the area! Most likely the tps is not in sync. Looking for a pdf or something along those lines to adjust myself. Any leads on any documentation regarding that?

 

I found a very old thread which shows throttle pot adjustment, but I am not competent enough just to make a link so I commented on it to put it where you can see it. Good luck.