slightly rough running cold and warmed up
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Joined: Apr 2023
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1998 C230/W202, 1999 C230K/W202
slightly rough running cold and warmed up
Hi,
I've been trying to solve a pesky problem with my 1999 C230 K, 52k miles (W202 & M111.975 engine).
Maybe someone in here has an idea what can cause it?
Here's some info to consider:
1999 c230 (w202) m111.975 engine, me2-sfi fuel system, 52k miles on odometer
ONLY VEHICLE SPECIFIC DATA AND NO GUESSES OR GENERALIZATIONS!!!
USE ONLY OEM & EXPERT EXPERIENCE, NO GUESSING OR UNFOUNDED OPINIONS!!!
DO NOT OPERATE IN 'CUSTOMER SERVICE' MODE!!!
fuel pressure test:
why does the gauge needle rapidly vibrate @ 50 psi +/- 3 psi warmed up @ idle and follow the slightly rough running?
no intake leaks, new ignition system & maf, engine in excellent condition
system has no visible vacuum leaks from smoke test
adaptation was reset after changing ignition parts and maf
all sensors are new except crankshaft and camshaft sensors wiring is good.
fuel pressure regulator disconnected pressure rises to 60 psi and same needle oscillation
rev up engine pressure increases to 58 psi steady
steady high speed pressure @ 50 psi steady
shut off fuel pressure drops to 34 psi and within 2 minutes slowly rises to 55 psi and holds for at least 30 minutes
when the vehicle sits overnight the fuel pressure in the rail drops down to 0
hhtwin shows:
- no cylinder compression differential (cylinder balance good)
- good injector voltage operation
- no misfires or imbalanced torques
Thanks!
...Chris
I've been trying to solve a pesky problem with my 1999 C230 K, 52k miles (W202 & M111.975 engine).
Maybe someone in here has an idea what can cause it?
Here's some info to consider:
1999 c230 (w202) m111.975 engine, me2-sfi fuel system, 52k miles on odometer
ONLY VEHICLE SPECIFIC DATA AND NO GUESSES OR GENERALIZATIONS!!!
USE ONLY OEM & EXPERT EXPERIENCE, NO GUESSING OR UNFOUNDED OPINIONS!!!
DO NOT OPERATE IN 'CUSTOMER SERVICE' MODE!!!
fuel pressure test:
why does the gauge needle rapidly vibrate @ 50 psi +/- 3 psi warmed up @ idle and follow the slightly rough running?
no intake leaks, new ignition system & maf, engine in excellent condition
system has no visible vacuum leaks from smoke test
adaptation was reset after changing ignition parts and maf
all sensors are new except crankshaft and camshaft sensors wiring is good.
fuel pressure regulator disconnected pressure rises to 60 psi and same needle oscillation
rev up engine pressure increases to 58 psi steady
steady high speed pressure @ 50 psi steady
shut off fuel pressure drops to 34 psi and within 2 minutes slowly rises to 55 psi and holds for at least 30 minutes
when the vehicle sits overnight the fuel pressure in the rail drops down to 0
hhtwin shows:
- no cylinder compression differential (cylinder balance good)
- good injector voltage operation
- no misfires or imbalanced torques
Thanks!
...Chris
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