KE-Jet Residual Pressure

Hasn't been reported as a common failure, but is possible. Even though your check valves are new, the possibility a new one is bad isn't zero either. You've got the right approach -- if the problem follows the pressure regulator = replace it. If the problem doesn't follow it = has to be something else.

No, it would not. During normal operation, valve 6 (see fig 56, page D78 in the TR WSM) is open (i.e., it is leaking a lot). At shutoff, valve 6 is supposed to fully close.

 

to eliminate some you first may change the left pressure valve to the right side and otherwise.
during operation the pressure always is ok? then you only may get problems when starting.

 

pressure valve or pressure regulator:

have a look here:
https://www.ricambiamerica.com/car-diagrams/ferrari/v12/testarossa-group/testarossa-1987/fuel-distributors-lines-ke-jetronic-system.html?mode=split
loation number 12, part number 125136
this is a bosch part, same as in the mercedes 500 SE
the bosch number is stamped on the housing. if not working right go to a bosch dealer and tell him you need this part. but don´t tell him it is for a F. then he will kust raise the price as all other always do

before switching the fule pumps I would switch the regulators - much easier to do

I think I still have here 2 in stock ( used ) but not sure, have to look if you need

 

One point is that the shutoff sealing doesn't need to be perfect (although it often is) -- that's why there's also a time interval given in the spec with the idea being that, after that much time, things will have cooled off enough such that the fuel in the lines won't vaporize even if the pressure has dropped some. (i.e., looking for perfect sealing overnight is an unneeded over-requirement).

The only other place in the system that there is an "intentional valve" that needs to be closed at shutoff to retain the pressure is the cold start injectors -- have you checked that for leaks? Not sure that you'll have any other choice but to swap the fuel pumps (with their check valve) if it's not the pressure regulator nor cold start injector on that bank. It will also give you a chance to ensure there are no leaks in that area (gasoline is so volatile that a small leak is often never a liquid that reaches the ground). Good hunting!

 

if this would be the reason then the fuel will not get over the fuel pressure regulator back into the fuel tank. then the fuel would go over the injectors into the cylinders/intake manifolds.

but I think now you send both out. so too late to test some more.

let us know when you get them back what have been done and how much you payed for and of course if after then all is ok what I don´t think so. I still believe the pressure valve one side is not working fine. you not told us that you checked those?

 

Hi Jeff, tried to answer your email as best I could, but for other peoples benefit I will post up my thoughts.

If you have a look at my CIS thread, (all courtesy of Steve Magnussan!) you will need to initially set the sensor plate to positions A, B and C.

After that I had to get someone in with a set of vacuum gauges to accurately set up the mixtures etc.

20170920_110531.jpg

This I understand was carried out with throttle body screws fully in, and once both banks were set the throttle bodies were them adjusted for idle.

I didn't quite fully understand what was going on, but there was lots of listening and feeling going on at the same time, but ultimately it runs extremely smooth now.

 

I believe the vacuum gauges were used to set the idle by-pass screws. To balance the side to side. The mixture screws: 3mm allen, I believe you need to read the exhaust mixture!

 

I wouldn't be too hopeful for it making an operational difference in the fuel delivery to the injectors (as a small leak in the return line path isn't going to change the regulated supply pressure and everything else that happens downstream is driven by that). Let us know how it goes...