Bogging When Cold

[Andrew J]

Afternoon all,

So after a few cold starts and with the engine under load, the car bogged down. It was only for a split second, but it was enough to send me hurtling towards the steering wheel at an alarming rate of knots!

There were no lights on the dash (my 320d traction light would come on going over bumps caused by a loose reluctor ring) so I don't think it's the reluctor ring or wheel speed sensor.

If it was the yaw sensor, I think this would happen more often and not just after a cold start and under load?
I've checked my code reader and nothing unusual there (only codes are the OE & OD codes for jam protection and oil level sensor which will get changed at next oil service as I check my oil manually).

My code reader (C310+) couldn't connect to electronic fuel pump so not sure if that's anythimg to do with the issue.

Any thoughts and ideas welcome as I'm out of both now.

Thanks,

Andrew

 

[Street]

The Engine ECU only cuts power when two or more wheels lose traction. You’d also have a Christmas tree on the dash so I don’t think it’s any of them.

I’m thinking air to fuel ratio mix is wrong.
MAF sensor on the way out? Try disconnecting it and let the engine run on defaults.
Idle Control Valve sticking? At cold it helps regulate air flow but less critical when warm.

 

[Andrew J]

The Engine ECU only cuts power when two or more wheels lose traction. You’d also have a Christmas tree on the dash so I don’t think it’s any of them.

I’m thinking air to fuel ratio mix is wrong.
MAF sensor on the way out? Try disconnecting it and let the engine run on defaults.
Idle Control Valve sticking? At cold it helps regulate air flow but less critical when warm.

I replaced the maf back in may as it had given up. I also cleaned the idle control valve at the same time and got it free again. It did it again today. It was damp but I was in a straight line and not under massive load. No traction lights again either. Very puzzling!

 

[arny14]

It used to happen to me, but only the first pull of the day, and not every time (10/4 lets say). Don't know the cause.