XJ_1990
NAXJA Forum User
- Location
- Washington, USA
I have an XJ 1990 4.0L. Harmonic Balancer went bad and slipped, so I'm replacing it. Decided to check the timing chain and it has more that 1/2 inch play, so I'm replacing it too ... but ...
I'm perplexed about the timing marks on the gears. When I have it at TDC on the compression stroke and the rotor pointing at #1 spark plug wire, the timing marks don't face each other. While the mark on the crank gear is facing the cam gear (expected), the cam gears timing mark is 180 degrees off on the other side. I just doesn't seem to match the books I have. I also count 62 pins and not 48 pins like my book says for a 4.0L.
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_timing_chain.jpg
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_dist_pos1.jpg
I'm the 3rd owner and it may be possible this is a rebuild or replacement engine. The blocks casting number is 701MX03 with a 97 to the right and a R1D01 or RTD0T below (kind of fuzzy pic below).
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_engine_701mx03.jpg
I don't think the Cam is 180 degrees off, but could it be? or am I looking at the wrong engine or parts?
Thanks,
Mike
I'm perplexed about the timing marks on the gears. When I have it at TDC on the compression stroke and the rotor pointing at #1 spark plug wire, the timing marks don't face each other. While the mark on the crank gear is facing the cam gear (expected), the cam gears timing mark is 180 degrees off on the other side. I just doesn't seem to match the books I have. I also count 62 pins and not 48 pins like my book says for a 4.0L.
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_timing_chain.jpg
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_dist_pos1.jpg
I'm the 3rd owner and it may be possible this is a rebuild or replacement engine. The blocks casting number is 701MX03 with a 97 to the right and a R1D01 or RTD0T below (kind of fuzzy pic below).
http://www.geocities.com/jacobsen_mike/1990XJ/xj90_engine_701mx03.jpg
I don't think the Cam is 180 degrees off, but could it be? or am I looking at the wrong engine or parts?
Thanks,
Mike