Vanos Rebuild Start Hesitation

[maupineda]

Are these separate tests from the main tests? I've only got as far as pulling VANOS adaptation values, and then running the main test which just gets the car to 1500rpm, sees 69.3 degrees and instantly fails.

I've only really touched DIS to look into this issue so I'm not overly familiar with the software.

No, they are all part of the test routine. I see now your test fails quickly. I would say is timing or the sensor is just bad. Start with the sensor as that is the easier/cheaper part. For timing, if you have the garage to check again, be there to see for yourself the car is indeed timed correctly.

[jamesfoley]

Seems like a timing issue. When testing VANOS, what are your speed and leak values?

Are these separate tests from the main tests? I've only got as far as pulling VANOS adaptation values, and then running the main test which just gets the car to 1500rpm, sees 69.3 degrees and instantly fails.

I've only really touched DIS to look into this issue so I'm not overly familiar with the software.

[maupineda]

Seems like a timing issue. When testing VANOS, what are your speed and leak values?

[jamesfoley]

I've had my VANOS rebuilt by a local shop using the usual Beisan parts, but since then have had an issue with the car hesitating to start, or just stalling instantly after catching.

Couple of people told me its likely a timing issue so the car went back to have timing checked and everything came back okay, but the car still has issues, so started going down the route of spark and fuel.

For what its worth the car has been throwing zero fault codes.

Here is a list of what I've one in the order I did them in:

• Inspection 2 including clearances
• Replace all ignition coils (Delphi)
• New fuel pump relay (OEM)
• New fuel pump (OEM)
• New fuel pressure regulator (OEM)

So did those over a month with no change to the starting. After a month though I'd noticed the car was very flat power wise, and the car also suddenly threw a DME fault, 94 Inlet Vanos adaptation, so I fired up DIS and instantly saw its not adapting at all on the inlet cam.

After being reassured the timing was good I figured it was going to be the valve body / coil pack, so threw a new genuine VANOS valve body and solenoid pack on the car and I get the exact same readings in DIS. The car also instantly fails a VANOS test stating the inlet cam position is "outside the tolerance band".

Adaptation values in DIS for the VANOS come back with a DME commanded 52.5 degrees to reach an actual 59.9 degrees on the inlet, and the test fails with the inlet retard position at 69.4 degrees. Resetting the adaptation values in the DME allow me to clear the fault code, and the car does seemingly drive okay, but it still just comes back with the same results in DIS.

Is this simply a case that the VANOS timing on the inlet cam is roughly 9 degrees out which puts it too far out to adapt? Also, does this mean my VANOS unit is basically not doing anything?

I started to wonder if the inlet cam sensor was failing but yea, I have no codes and consistent positions in DIS. Sort of expected a sensor to either not work or just be throwing random values everywhere. Was also starting to wonder about the impulse wheel on the end of the cam, but again the results I get in DIS are consistent.

Would the inlet cam being out of time also be the cause of the intermittent start hesitation? I don't know if perhaps the VANOS has to hunt for a 60 degree position on the inlet cam every time the car starts if it cant adapt. For what its worth the exhaust cam adapts fine and looks good.

Any help would be greatly appreciated.