Re: [DML] Re: impossibly high fuel pressure?

[Soma576@xxxx]

In a message dated 4/11/01 10:12:56 PM Central Daylight Time, 
jtrealty@xxxx writes:


> Refer to parts manual 2-1-0 part # 14 or 102359 fuel pipe. Follow to 
> fuel distributer and remove at the fuel distributer. Hook a temporary 
> pipe onto the fuel distributer and place the other end in a pail to 
> catch the fuel. Run the fuel pump (jump the rpm relay) and read the 
> PRIMARY PRESSURE. (Refer to workshop manual D:02:02 for correct 
> procedure). It is possible for a problem in the control pressure 
> circuit to cause primary pressure problems like an eroded restrictor 
> but I don't think that is the trouble. Until you can get your Primary 
> pressure under control don't worry about control pressures. Although 
> you ran a flow test to the tank I think you have a problem with the 
> return hose and even though you got good flow at the tank it had to 
> get past a restriction that is causing high pressures at the fuel 
> distributer. By disconnecting the return at the fuel distributer you 
> will be "bypassing" any restriction and allowing the fuel to dump 
> letting the primary pressure regulater work. Since you are deep in the 
> fuel system I recommend you go to www.motorbooks.com and order book # 
> 112910A for $29.95 Bosch Fuel Injection Handbook and Engine 
> Management. It gives a very in depth description of the operation of 
> the K-Jetronic fuel system and troubleshooting procedures. Be careful 
> in getting advice from people not specific to the Delorean. There are 
> slight changes in the fuel systems from car to car and what may be 
> valid for a Volvo for instance may not be true in a Delorean. The 
> Primary pressure regulater sets system pressure so if it is too high 
> it is only because it is not sending excess fuel back to the fuel tank 
> for whatever the reason. A failed cpr should not increase the system 
> pressure although it can reduce it.
> David Teitelbaum
> 

OK,

i will be sure to try your above test tomorrow David. 
here's some new info:
today i put a different DMC fuel pump in my tank. mine has been making 
strange noises, so i thought i'd put a different one in just to see if i 
could eliminate any doubts. well now my control pressure is around 3.0 bar, 
and the system pressure will slowly increase to about 4 bar, then it suddenly 
drops down to about 3 bar and sits around there. every time i jumped the 
pump it did this. it would slowly rise up to 4 bar, and right about there, 
in the same place every time, the needle would violently drop to about 3 bar, 
and that's where it would dwell at. very interesting. my old pump would go 
to 3.5 for control pressure and go all the way up to 6 or 7 for primary, and 
it jumped around in that area. 

got any explanations for that, David? or anyone?

Andy

Soma576@xxxx
1982 DeLorean DMC-12 VIN#11596
Fargo, ND 58102


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