Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Test Point 7 - Fuel Pressure

TEST POINT 7 - DME 944

Fuel Pressure (Pressure Tester P 378)




There is a cap nut on the end of cyl. no.1 injection line. Unscrew cap nut, being careful that sealing ball does not fall out!
Connect pressure tester P 378 on adapter.

Start engine and run at idle speed.
Test pressure: 2.0 bar (29 psi)

Pull off vacuum hose on pressure regulator.
Test pressure: 2.3 - 2.7 bar (33 - 39 psi)

Squeeze return hose of pressure regulator tight slowly with a hose clamp.
Pressure below 4 bar check fuel filter, replace fuel pump.

If engine cannot be operated: Bridge terminals 30 and 87 b on DME relay G 5.
Fuse no.34 okay.
Specified test pressure value: 2.3 - 2.7 bar (33 - 39 psi)