K-Jetronic Recommissioning

[Beetledrive]

Originally Posted by stephend

Two relatively easy things to try. One is to clean up / de-gum around the air metering flap; the other is to check the idle air bypass valve (tubular thing bolted to head, with pipes into the top and bottom, and a half-moon flap inside).

I agree with this for easy tasks. The throttle body housing just attaches to the bottom of the air unit with three bolts. You will need to take off the bellows, pull off one fat hose, and pull off the small hose at the back that goes to the distributer for vacuum advance. You will also need to unclip the bottom of the throttle link rod.

It will probably need a very good clean with a toothbrush and lots of carb cleaner. Once clean you will need a new gasket from Volvo which costs about £2. I think the part number is 1271488 (please check this is the correct one for yours). I did this last weekend on a B23E and it almost took off when we started the car again.

It looks like this:



The auxillary air valve looks like this (and also needs a clean with carb cleaner):

[wooble]

Originally Posted by Trommel

There are no fuel leaks - what effect could new seals make?

Had thought the cold start injector might not have been working, but it won't start when hot either.

The rubber o-rings that seal the injectors to the head are known to disintegrate with age, causing vacuum leaks to which k-jet is very sensitive. Likewise any vacuum hoses which may have deteriorated. Often as they deteriorate and begin to leak air, inexperienced owners / mechanics adjust the mixture screw in an attempt to compensate, so the engine runs pig-rich when they are repaired until the mix is reset.

A standard tune-up of all filters, plugs, leads and cap/rotor is always a good start, as well as checking hoss and hose nipples to ensure none are collapsed, blocked or leaking. It's unlikely that any fuel lines are blocked, but is the car was standing a while there may be rust / dust / debris in the tank which has been sucked up into the filter after starting it.

[Trommel]

Thanks all for the suggestions - I'll give it another go in a couple of weeks.

Had forgotten what a pain it is to get to the plugs and distributor on the V6.