[DML] Re: Fuel pressure values

["Harold McElraft" <hmcelraft@xxxxxxx>]

I would suspect a malfunctioning or improperly connected pressure 
regulator and/or frequency valve.

Harold McElraft - 3354



--- In dmcnews@xxxxxxxxxxxxxxx, "cruznmd" <racuti1@xxxx> wrote:
> 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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