Starts then loses power - P0351, P0353
 

Need help with figuring this out. Thanks in advance. I have searched lots of threads, but haven't been able to fix it.

My son bought 2000 XJ sport about 6 months ago and it has been running like a dream. Recently had gears changed, and new valve cover gasket for a leak.

My son was driving on highway and engine started chugging, then lost power. It would start back up, but any throttle it would chugg and stall. Towed it home.

Checked code reader and got P1391 (loss of Cam or Crank) and 0351, 0352, 0353 (Ignition coil 1-3).

• changed Cam sensor (didn't see much wrong, but some rust) -

Same problem (starts but loses power after a minute of idle, or giving some throttle), but code P1391 now gone but still Ignition coil codes 0351 - 0352

• Changed coil pack (and plugs while I was there) - the connector didn't have the red slide that locks it on, but is all the way on and snug

Same problem (starts and idles, but then chuggs and stalls) and codes 0351 - 0352

Any help would be appreciated. we are pretty hand with mechanical stuff, but now sure where to go with this electrical issue. Thanks!

So after doing some more reading, I replaced the crank shaft sensor and cleaned up all the grounds throughout the vehicle. We live in AZ, so barely any rust on any of the grounding spots. Went through the wiring and no evidence of rats chewing anything.

Cleared the codes, then started up again, and same thing happens.... idles for a minute, then boggs down and dies. Start up and give any throttle, boggs down and dies. COdes p0351 and 90353 still there.

I am stumped. Any help would be appreciated.

Thanks!

my next guess would be fuel pump. have you checked the fuel rail pressure?
i'm having a similar problem. starts and runs fine for 15 or 20 min then starts to chug, spit and sputter. will run good below 20 mph, but won't go any higher. cut it off and let cool for awhile and runs good for awhile, then repeats the stalling. i'm waiting on a pressure tester now. my xj is at the camp so i won't fool with it for a couple weeks. hope someone chimes in with some help.