Simple Guide to CIS injection (2.8 engines)

[RCK974X]

Guys, I wrote a wiki thread in Wedges, after I was asked to provide a simple description of how K-Jet / CIS works, and then I realised it's useful for you guys too, so go and have a look !!

[v8s4me]

Lazy people can just CLICK HERE

[Le TVR]

With CIS you can't change the fuel filter TOO OFTEN, do it yearly.

The CIS has 2 fuel filters, the big primary filter on the supply line and a smaller one integral to the WUR. If the WUR Filter gets blocked then you lose the control pressure as all the fuel pressure is released back to the tank.

Most WUR are physically identical, all the different versions are down to how they are calibrated for Temp v Control pressure.

1. Don't adjust anything without first checking the control pressure.

[v8s4me]

Le TVR said:

.... the big primary filter on the supply line and a smaller one integral to the WUR. .....
.......

How do I check that?

Le TVR said:

.... .Don't adjust anything without first checking the control pressure....

How would I do that?

[Le TVR]

v8s4me said:

Le TVR said:

.... the big primary filter on the supply line and a smaller one integral to the WUR. .....
.......

How do I check that?

Get the WUR refurbed and recalibrated. Try KMI.

Le TVR said:

.... .Don't adjust anything without first checking the control pressure....

How would I do that?

something like: https://www.rallysportdirect.com/part/fuel-pressur...

[v8s4me]

Would my erratic tick-over problem ( see other thread) be due to a faulty WUR?

[Le TVR]

Quite possibly the vacuum applied to the WUR is to lean it out under idle/high vacuum conditions. If pulling the vacuum line off gives a stable idle the control pressure is probably too high, so IMO worth a WUR clean and calibrate.

[v8s4me]

At £220 for a WUR refurb I'll need to be sure that is the problem.