Re: CIS mixture adjustment keeps getting lost. Why?

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <m0zqqoa-000JvgC@post.cis.smu.edu> rjandrew@post.cis.smu.edu (R Justin Andrews) writes:

> Ok, this is an '84 5k right???
> Those are not CIS but K-jetronic injection... I believe there is a difference..
> Yours has the exterior warm up regulator (on the driver's side of the block)
> Two fuel lines running to it?? Correct? I had one of these stick on the on
> position... not good same basic symptoms... after warm up there is only
> supposed to be pressure on one side of it.... try hooking up 12v and blowing
> through it with an air gun.. if it opens release 12v and try now you should
> of heard a click and then no flow... if not this is your problem.

Strange diagnostics.  The 12v is only a heater - wired in parallel with
the fuel pump.

The regulator should return about 2 bar (-ish) when cold, and 3.4 bar
when warm/hot.  The pressure it provides is applied to the top of the
plunger in the metering head - if it's too low, the plunger rises too
far and the mixture goes rich.

There are two failure modes - high and low.  High just seems to go to
around 4.2 bar and stay there - low tends to fall and then suddenly
drops to zero, stopping the car.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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