1989 Jaguar XJS won't pass smog

REX L MORGAN

MEMBER
1989 JAGUAR XJS

Computer problem
1989 Jaguar XJS V12 Two Wheel Drive Automatic 98.000 miles

Hello I'm having trouble getting a jag I just bought to pass smog. The tech say's it's pumping too much fuel way too rich. The tech say's mabey not coming out of cold startup loop mode. I did a full tune up myself changed all filters, replaced the fuel pressure regulators (2) and also replaced two of the cats. Still no pass. Some people seem to think computer replacement how do I tell if it's a bad computer and is the one I have adjustable I heard some are mine is a DAC 6337 LUCUS 16 CU CONTROL UNIT 8478B with a date code of 4588. The unit does have a hole on one side with what looks like a recessed stainless steel rod? If the one I have is adjustable how do I do it

1 Reply

FSTRANGER302

MECHANIC
117 POSTS

Hello, this computer is adjustable. But you have to have a special machine to hook up too watch the mixture. Chances are it is ok. Is the car getting warm enough. A bad themosat can cause a car to run rich. Also rember your car has two thermostats. Also if the coolant temp sensor is bad it too will cause fueling problems.L let me know if I can help any more
rep points apreciated for the infor if it helps