[DML] Fuel pressure values

["cruznmd" <racuti1@xxxxxxxxxxxx>]

My car is experiencing a loss of power. Symptoms are:
Flat acceleration curve. With 1/3, to 1/2 pedal applied, car 
accelerates smoothly but slowly, depress the pedal further and the 
engine stumbles mightily and the car bucks. Swapping CPR's with a 
fellow owner did not correct the problem. RPM relay was checked and 
is operating correctly. All fuel components are new except for the 
accumulator. (1.5 years old or less). I'm currently getting 21.45 
MPG, and the lambda system is operating correctly.

A Bosch K-jetronic pressure test rig reads the following values:

When the rig is installed with the T-valve towards the distributor, I 
get the following pressures:

Valve open: 0 (zero) bars/psi.
Valve shut: 4 bars.

This didn't seem right to me, so I turned it around so that the T-
valve was towards the CPR. (John H. later confirmed this for me) With 
the engine off, RPM relay jumpered I read the following values:

T-Valve open: 3.7 bars (control pressure)
T-Valve shut: 4.5 bars (primary pressure)

Engine running (RPM relay installed normally), the following values:

Valve open: 3.7 bars
Valve shut: 4.6 bars

The manual states that the nominal values are:

Primary pressure: 
   Checking pressure: 4.9-5.5 bars
   Setting pressure:  5.1-5.3 bars

Control pressure:
   Max: 3.5 bars (when hot)
   Min: (when cold) 1.4ish bars
-------------------------------------------------------------------
Assuming that I had the rig set up right (I'm fairly confident), my 
control pressure is a tad high, and primary pressure is a tad low. 
Combined with possibly dirty injectors could this account for such a 
dramatic loss of power? I also discovered that my air filter is 
filthy already too. (9 months old)

To put this in perspective for my fellow Americans; 

I have as much as 3 psi too much control pressure,
and anywhere from a 7.25-14.5 psi LOSS of main line pressure.
(1 bar= apprx. 14.5 psi) (Which primary pressure value do I 
use? "Checking" or "Setting"?) See the fuel section of the workshop 
manual. Am I making too much of this small variation in values, or is 
that enough to make a difference? Personally, I think my fuel pump is 
too loud even though it's only been installed for 1.5 years. I 
believe it's NOS, old style. Internal check-valve. Maybe it's dying?


What say you?

Rich A.
#5335




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