D-Jet Problems, Stalls when hot, misses at med. rpms Options

[john_g]

I'm having problems that I'm pretty sure come from somewhere in the D-jet system. I have a '74 914, bored to 2056. Here are my symptoms:

It idles okay. It's a bit rough when cold, but it doesn't cut out on me and warms up to a steady idle quickly (1200 when cool, 800-900 when warm), but when it's been run for a longer time and is good and hot, the idle drops well below 800 and it stalls. It'll start back up right away but only if I treat it as if it's flooded - I have to put the accelerator to the floor as I restart it. Secondly, at mid rpm's, between 2200 and 2800, it hesitates, sputters, misses, and occasionally backfires - this happens whether it's cold or warm.

What I've done or have had done:
usual tuning routine
replaced the CHT sensor
replaced the MPS
replaced the distributor
cleaned the PVC valve
checked for vacuum leaks
checked the TPS, it seems good

Two air-cooled mechanics with good reputations have worked on it and haven't been able to solve the problem fully. All the above helped a bit, but the situation is still there. There has to be some sensor that isn't reading the situation correctly. Any ideas, or ... has anyone had a similar problem? (IMG:style_emoticons/default/confused24.gif)

[boxsterfan]

Everything you ever wanted to know about d-jet.

http://members.rennlist.com/pbanders/djetparts.htm

My car had trouble at idle after warm-up and I got one of these Porsche 914/4 Cylinder Head Temperature Sensor Extension (about 3rd item down). My problem was that it was running well at warm-up (idled at 1400-1600 depending on I adjusted the idle screw) but would stall as she came up to temp. Once she got warm though, I never had your stall out issues.

http://914ltd.com/store.php?c=1384303079