Hello so I have a 1998 VP that seems to have a fuel issue that when I turn a corner sharply it seems to be awarded for gas for some time after with it lunging with power and no power unless lightly on the accelerator.
next when at speed it will vibrate when accelerating and then stop when cruising.
I'm not sure if it's related to the fuel issue that it maybe sputtering very quickly to feel like a vibration or if it's something to do with u joints
Any ideas.

 

The 'U' joints or the JURID couplers?
The couplers can deteriorate and move out of alignment, especially during acceleration.

 

Here's a write I did when I did my carrier center bearing and my jurids, its worth a review... https://www.jaguarforums.com/forum/x...g-info-188400/

 

The first issue you have while turning a corner quickly, does this happen while turning a hard left and right? Or more so one way vs the other?

Regardless of your answer, I’d first look into your motor mounts. If you have the hood open, emergency brake set, brake pedal down hard maybe with a chocked wheel(s), sport mode (not 100% necessary but this is what I’d do) button in the full up position with the little red (if that led even works) led on, nothing in front or behind the car, give it about 50% throttle quickly and then let off right away. Naturally the engine will have a small amount of movement but, if the engine raises several inches upwards and your air intake pipe bellows is on its last leg, it could in fact have a notable gap that would have a substantial power loss like you mentioned. Do the same procedure in reverse gear. The important thing to remember is while doing this “power brake” procedure is to not have the throttle depressed for more than like a second at a time because the transmission heats up the fluid very quickly and that’s bad for it. I would do this procedure as a first start in the morning after the engine has ran for about 30 seconds just to be safe. So do the procedure in D for one second, note roughly how high the engine lifted on the right hand side, after you let it off, wait for about 15 or 20 seconds then do the same for R. Because the car spends about 99.9% of its life in D, it’s likely to have a higher lift in D vs R.

As far as the second issue, I’d highly suggest what highorse stated about the driveshaft center support as well. It’s entirely possible that there’s other things that can cause that but, that center bearing is a known issue area. Also look into the transmission mount as that can affect driveshaft angles and cause vibration as well.

Motorcarman is also correct about his suggestions. Let’s face it, our cars aren’t getting any younger and ALL the supple rubber components they once had in these cars are susceptible to sagging like an old woman.

 

Thanks for the advice gents. The car did sit for six years and I have already replaced the front shocks because the mounts were crumbled to bits. And I do know that the right rear top bushing must have crumbled as well because of the knock it has over bumps. So could be mounts for motor and trans.
or all rubber bushings. Only has 85 thousand miles on it but at that age and after sitting. Well the rear shock bushing will have to wait itblooked like way to mush work removing the whole rear axle from what I saw in the service manual.
I have hear the the engine mounts are a beast as well.
I'm a driveway DIY guy but its just me so may have to save up and have someone look at it.

 

The motor mounts aren’t terrible. The hard part is getting the top nuts loose because the underside of those nuts are toothed which is embedded into the aluminum. There are some words of caution but, when you go to do them, either other forum members and/or myself will tell you about the cautious areas on the motor mounts.

The possibility is high that all the rubber stuff under the car does need replaced but, let’s just focus on fixing the initial problems first.

When the rear upper shock mounts are tackled, plan on doing both sides at the same time. I strongly recommend getting the Jaguar oem large donut mount vs getting the cheaper aftermarket ones. There’s 3 bushings to replace on each rear upper mounts so 6 pieces total. Also, if the car had a lot of rust repair in the past, plan on running into some scary surprises. I’ve heard the rear subframes rott out in high road salt areas depending where your car came from. Completely saturate every fastener with your favorite rust penetrating fluid and let it sit overnight as a minimum before wrenching on it after you put the backend of the car up on jack stands.

 

No rust issues thank goodness it's a Florida car and was stored indoors