Dont Know what you have done or not done sounds like a lot of stuph that has not panned out.. I have had a simmilar problem with a 71 160... I ended up dropping the fuel tank to find it full of rust and misl... If you have not done this it is time and will more than likely be the problem,,, I have also had to do this same thing to several 140s i have had.and one of the manny 240's. only have had the one 160, If you have allredy done this sorry And I hope yopu get it figured out...


Thomas.......... 208-573-2925

Look a the injector holders. Each should have two phenolic washers on the bolt holding the mount to the head, one between the mount and the head, and the other between the mount and the bolt cap. Those provide thermal insulation that keeps fuel from vaporizing in the injectors, which seems to occur most often exactly in the situation you describe. They are often broken, lost or discarded when the seals are changed.

If you don't have these, try adding them. You will also need to renew the large O-rings under the mounts, as the ones on there will have been over-compressed due to the thickness of the lower phenolic washer being missing.

It could be spark plug temperature rating. Try going to a hotter plug (but not to the maximum) especially if you have a lot of miles on it and therefor maybe a wee bit lower compression value. When you come off the highway you are at a different temperature soak then 20 minutes later your motor temp soak has equilabrated to a stop and go traffic value. This is just a hunch but easy to try! Vacuum leaks are really likely but you've been through that, right? ;)
--
Genesis 7:11

Howdy,

This is interesting:

...The throttle valve switch is mounted on the throttle housing. This switch signals the control unit of throttle position. During deceleration, above 1500 RPM, throttle switch cuts fuel supply off and below 900 RPM, fuel supply is turned on.

What if it is sticking? It is worth the investigation.

I found that here:
http://www.icbm.org/erkson/ttt/engine/fuel_injection/d-jet.html

sd

Just a stab in the dark, perhaps the centrifugal advance or vacuum advance on the distributor is dirty/damaged and gets stuck when you had been driving with a wide open throttle? Perhaps the distributor vacuum hose collapses under high vacuum and takes a while to recover?

Being an "E" (D-Jet FI), the manifold pressure sensor usually fails with a leaking diaphragm and perhaps yours have an intermittent leak which develops when suddenly closing the throttle. Or the throttle position sensor is dirty and gets stuck when wide open for a while.

Sometimes you get funny faults, for a while my car would suddenly stutter and die after starting in the morning, then start up fine after a minute or two and be fine all day 'till the next day. That turned out to be the distributor cap centre electrode that was broken off and in the morning the car would die when condensation created a leakage path for the high voltage, disappearing with a few minutes heat soak.

For later cars with Bosch K-jetronic, the type of stalling that you described was invariably (99% of the time) caused by a vacuum leak. Hoses were brittle, the oil fill cap gasket was worn, the gas cap was loose, the dip stick O-ring gone, etc. It was frustrating to track down.

The intermittent weak idle can sometimes be the hoses that go to and from the auxiliary air valve, and the AC solenoid valve, if you still have it. They get hard over time and don't conform as they should. They'll shift under braking and very low manifold pressures - like backing off at high RPM, and cause the weak idle.

Sounds temperature-related and might have something to do with the temp sensors
also. I'd check both of them and watch the temp gauge. If you drive fast for
a while and suddenly slow down your temp goes up because the cooling system's
efficiency is related to water pump speed but the engine heat lags behind
so when you slow down the engine is still hot from running fast and it takes
the cooling system a while to catch up. Meanwhile if the D-jet thinks it is
very hot it will make the mixture lean, possibly too lean to start.
On the other hand if you have a sensor problem it might think that the engine
is cold and may run it so rich that it floods instead of starting.
I guess you have double checked ALL the FI ground connections....
--
George Downs, Bartlesville, Heart of the USA!