1988 xjs 12 cyl.
 

Gentlemen:
The girl of my life (yeah the other one!) has a 88 XJS 12cly. fuel injected. I can get the passenger side bank to fire but not the drivers side.
What has been done;
1. Feul tank and system flushed.
2. New fuel pump installed.
3. New spark plugs/cap wires

I think there's a possible clog in the fuel line or a stuck check valve any ideas?
Thanks once again

B

"Not fire" as in no spark on one bank? Or "not fire" as in fuel injectors are not working on one bank ?

Cheers
DD

88 xjs
 

Thanks will check spark I assumed it was getting spark as pass. bank was firing.
Aren't the injectors fed off the same fuel rail?

Same fuel rail, yes, but electrically the injectors are in four groups of three. Take a good look at the injector harness as it's a known trouble spot.

Since the car is an '88 it should have Lucas ignition and there should be no reason for one entire bank to loose spark. If you had Marelli ignition then loss of spark on an entire bank is common.

Are you sure it's an '88 model year? The Marelli system was introduced part-way through the 1989 model year.

Cheers
DD

My car has a production date of 8/89, it has the lucus ignition

The cut-off point was at VIN 156118 or something like that......156xxxx

Cheers
DD

8/89 is most likely Marelli mine is 4/89 and has Marelli. Check to see if there are 2 orange ignition modules on the top radiator support. If so it's Marelli.

I was mistaken, my car does have the Marelli ing. I was looking at something else with the lucus name on it. Does this mean I'm going to have more problems.

Only if you don't give the Marelli system proper attention every 30k miles or so :). The infamous Marelli induced problems (fire, most notably) result from owners simply not being aware that the ignition system can't be ignored. It needs love.

In a nutshell.....

Begin by pulling the distributor cap to check for rotor burn-thru and badly degraded contacts inside the distributor cap. A small glob of silicone inside the rotor (where it mounts onto the dist shaft) is a good idea.

Next, make sure the spark plugs are in good shape and properly gapped @ .025"

Then make sure the plug wires are in good shape and not too resistive. In in doubt, replace 'em.

Most importantly, if you're driving along and feel a loss of power, stop driving immediately. There's a good chance that you're feeling "Marelli failure" where one entire bank of cylinders shuts down. Bad things ensue.

That's it, basically.

There's always a chance of a coil or module failure but, other than checking wires and connectors, those things are beyond your control.

Cheers
DD

Only if you completely neglect it. My car has 260,000km and has never gone up in flames.

The 5.3 is a bugger to replace the front 4 spark plugs so they never were replaced. This causes the plugs to stop firing, and with the high voltage the spark has to find a path to earth and it will find the easiest path first through the lead until this breaks down then the rotor. THIS is what causes the Marelli rotor to fail. If you maintain it, replace the plugs at the correct intervals you will not experience this failure.

If you are still experiencing a dead bank you need to determine where the problem is. I would take Dougs advice and pull the dissy cap and check the rotor. Then pull all the plugs may as well replace them while they are out.

Ignition lead resistance can vary wildly depending on the type. Standard OEM leads tend to be around 16000Ohms per meter where as performance leads can be as low as 500Ohms per meter.

If it is still dead there are some simple diagnostic methods to isolate the problem we will go through these once you report back.

i have a Jan 89 car 158771 , Marelli ignition


think of the system as two independent straight six engines……….


one bank fault could simply be one of the coils not firing, there are two mounted on top of each other by the throttle capstan , the lower one is usually neglected ,

a very quick and easy test is to swap the coil feeds and see which bank is then firing, if the fault swaps sides then you will have a starting point

do not also forget that this system has a power resistor mounted behind the drivers headlight, small silver box with green label , the injectors are always live and the power resistor allows the firing of the injector when required, check the plug etc, as this part isn't usually associated with the ignition system and is not tested

BB

ps, 89 model year means it was built from mid 88 onwards , a US car will have a build date and an import date , these can be different years, the VIN is the only real way of identifying the systems on any particular car ,

Slight course correction.

Azblindguy isn't the guy with a dead bank of cylinders. Protech is, and he probably doesn't have Marelli...but it would be nice to verify that. We haven't heard back from him.

Cheers
DD