QuestionQUESTION: Hi there, I've recently purchased a 1985 Jaguar XJ6VDP. I'm very excited to work on the car myself, but I have a few questions that I want to ask before I get started.
-The rear brakes need replaced. I took the car to a brake specialist, they said that the calipers are leaking, the rotors are shot, and its a 10 hour job. That would cost $1500 in labor and parts. I have already bought all the parts that are needed for around $350, so I've saved a ton of money, now comes the hard part. I know the rotors are in the center of the rear axle, what should I be aware of when doing this repair? Any tips, pointers, or guidelines, I should follow? I know its a big job, I'm just concerned with issues unknown to me.
-Second, it runs very heavy on gas, if I apply to much gas it gets bogged down. It also idles very rough, almost dying. I have replaced the air and fuel filters, along with the spark plugs. I cannot get the car running much better. Any suggestions or tips? Also, when I hit the gas when idling, black stuff comes out of the tailpipe, it looks like oil, what could that be?
Thanks in advance for your expertise, I appreciate your help.
ANSWER: Hi Blake,
As far as the rear brakes go, you should not even consider doing it yourself unless you have a service manual because you have to drop the complete rear suspension and subframe out from under the car and disassemble the suspension and axles just to get to the calipers and disks.
Black soot and black smoke out the tail pipe is a clear indication of excess fuel. If the car is run this way it will for sure destroy both CATs, the front one and the second one.
This is a Bosch "L" jetronic injection system and again you need a manual to even start to diagnose such a problem. For me to walk you through the tests it would take a book of e-mails to do this. Electronic injection is a complex system and requires extensive studies to learn the system and how to diagnose problems. There are dozens of things that can go wrong to cause an injection system to run too rich with fuel. You would need some test equipment and the manual to follow the test procedures. This is not a system that you can just go turn a screw and fix.
If you want to try to repair the car yourself and get a manual and tools and proceed and run into snags, I will try to get you back on course but I can not teach you all you need to know by e-mail.
Howard
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QUESTION: Ok, thank you for getting back so quickly!
I have purchased the service manual, I'm just waiting on it to get here. I know the brakes are going to be time extensive, but I'm documenting exactly what I take off in what order, and hopefully soon I'll get the book to assist me even further. Is there anything tricky or extremely hard in taking apart the rear brake system, or is it just time consuming?
With the fuel system, would I be better off to just take the car to have test run at a mechanic shop? I want to do it myself but I have no idea where to even start with this. Would it have to do with air flow? Mass airflow sensor?
Thanks again for your speediness and expertise!
AnswerWhen you get the book just follow the sequence they detail. It is a lot of work.
The air flow meter is just one of dozens of possible items. You will run out of money before you find what is wrong if you try to replace every part that is involved. You would be wise to locate a shop that is familiar with the Lucas/ Bosch "L" Jetronic injection system. Don't let just any mechanic work on it, only a mechanic who knows the "L" Jetronic system.
Howard
