Greetings all. I have a 1998 XJ8 that im trying to get in stable condition to sell as my 2004 X-type is all I need and I can't do anything but AWD.
I just got the valve index cover gasket replaced as I had a slight leak in the front that was causing some white smoke. It was just fixed and when I drove it home it drove like SH*T to put it nicely. Wouldn't hold a charge even though guys at the shop charged it for days.
It's a new battery but w/e I knew it would drive with jump, it failed to start first turnover(like usual) and then started on second turnover but misfired and shook like hell. I drove it home and felt like it would shut off any moment so I kept gas to it while in park at each light. Got it home restarted it few times then if failed to start one of the last times I tried it. Restricted performance message of course was on whole time plus steering message.
I TOOK VIDEOS, so you can get an idea of how awful it sounds and runs. PLEASE watch all 3 so you can see the various issues going. Mechanic unfortunately speaks zero English and I speak zero Spanish however he thought ignition coil or spark plugs or something.
If you may please help me solve this issue as this has been a pain for over a year now. Thank you kindly.
Google Photos <- link

 

First - you have a CEL. Get a code reader and report back, there's a decent chance that at least part of the cause will be stored in OBDII error codes.

"It was just fixed and had a new issue after the repair" typically this means that the new issue was caused by humans, not by a coincidental failure that just happened at the same time a person had their hands in something. This holds true across industries...
Basically what that means is work backwards from what the person who did the repair would have touched, assume they're negligent or incompetent, and check anything involved in the service. So, in the case of a valve cover gasket, that means:
-Air intake properly reconnected (including breather hose)
-MAF harness reconnected
-part load breather reconnected (the one on the left/USA drivers side)
-coil packs reconnected (and properly!)
-valve cover gasket seated properly (and not sucked in or loose in one spot)
-any other harnesses the mechanic may have moved, not damaged or disconnected

I'd wager money the CEL will tell you what to check first.

 

I appreciate the list of things I should check, lost my reader for a minute but I found it so I'll check it out and get back to you. Thanks.

 

I hear a big vacuum leak.

 

I tried checking the things I quoted and I ended up verifying all of them were good however I cannot check the valve cover gasket as it's a PAIN of a job on the XJ8, which is why I had someone else do it. As the bolts and many hoses are in obscure places. I tried checking the codes and got ONLY a P1000 which i know is basically just BS and a default code. I'm pretty sure that can't trigger check engine light however so I'm not sure why it's not pulling more. I will update you once I try again here in a few minutes to get the codes again. Trying a different reader.

 

Battery turned out to be crap so I exchanged no starting issues since. Still have restricted peformance and codes only read is misfires

 

hello Vegang,

only misfires? what are the codes?

 

hey! they are p0351, p0352, p0353, & p0354 lol