So long story short, I got a 2001 Jaguar S Type 4.0 v8. Couple of days ago I finished swapping engines. Then new engine that I put there is from a 2000 Jaguar S Type, engine and the tranny both. On start I got a rough idle, vibration in the car. After looking around I found out that the car is operating on 5 cylinders. There is a spark, coils are good, and there is compression. Also transmission works rough, quick gear change with a slight jerk. My question to you is, could all of this be caused by an ECU? I haven't replaced those yet , so I was wondering if that could be it before I start pulling everything out. Just to clearify the other engine was pulled from a car, so I have the actual ecu that was on the 2000 jag. Any help would be welcome. Thanks.

 

Last suspect.

Swap coils, does fault move? Next if you're 100% sure wiring (*) etc are good is perhaps injector.

(*) Note: do the workshop manual pinpoint tests.

 

Did swap coils, no change. Wiring is good so are the injectors. You dont think it could be the ecu? I didnt swap them i left the old one in.

 

They're not just swappable anyway. Tied into immo and car will go anti-theft.

It's not going to be the PCM. Study fuel trims etc, if need be get WDS / IDS. You'll spend forever if you swap PCM...

 

What about the throttle body?

 

Up to you whether you prefer to swap parts or get data.