rev's down off idle

[alauder]

I have a 2.0 74 with all the D-jet in place.

My question is that when the car is cold idling at about 800rpm and I give it some gas for a fraction of a second the revs drop before the pickup occurs. How can I stop this? Is it running lean?

-------------------History--------------
Someone has adjusted the pressure sensor in the past, as the epoxy seal is gone.

It was running really lean (to pass smog) till last night. Lots of hunting and no power below 4000rpm. Even though the screw on the brain was turned all the way rich.

I read Kjell Nelin D-JETRONIC FI HELP. http://www.914fan.net/djet.html

Then turned the screw on the Pressure sensor anti clock wise about two turns. All the problems went away apart from the slight retardation when I step on the gas.

[alauder]

Oh!

I just read norustscott's post "po stuff/ d-jet follow up" about the same thing. Maybe I have a 1.7 Preassure sensor too. I could try adjusting it even richer?

Andy

[mejulihn]

In my opinion, there is probably a reason the MPS has a "sealed" adjustment screw. If it were meant to be routinely adjusted, no doubt the factory would have allowed for that (e.g., the idle adjusting screw in the throttle body and the fuel mixture knob on the ECU). I believe those who venture down this path do so at their own risk!

[norustscott]

I agree. The seal is there for a reason! I now have 3 old MPS units in the garage all w/o the seal and in unkown adjustment. Furthermore, they all have different part numbers on them...I picked up 3 for 5 bucks @ a swap meet, and two of them came with the car about a month ago. Of these two one is the 2.0l unit and the other is a 1.7l. The 1.7 got the car running but with several problems...Anyway, I believe my 2.0l problems are a result of this unit sending bogus data to the ECU. I have replaced all of the sensors and the TPS with new bosch parts from Pelican. Vacuum leaks have been corrected. I have just ordered the new Bosch MPS 0280100043 for the 2.0l I plan leave the seal alone. The tech article mentions a metered adjustment procedure. I also plan to experiment with the other units for a back up. I will pass along any success/failure. This is the big buck FI part. Local distributors have quoted from 560 to 870 bucks!

I have even cracked open one of the swap meet parts. This is a really neat unit. This is what makes the FI system electronic. It converts the mechanical function of manifold vacuum to an electrical signal. This signal is sent to the ECU To instruct the injectors to fire the proper amount of fuel. My ingine has run lean to the point of a popping backfire to the adjusted extreme of 11.5 MPG. I simply cannot adjust to a correct midpoint. The 1.7l unit is either bad or not compatible with the 2.0l displacement. I hope in the future to pass along insight to cost saving measures...I look forward to further discusion...Scott