M104 300te cold start?

[jaymanek]

Guys my estate is running rough when cold and also is hard to start. How does the cold start enrichment work?

When it's cold I have to let the car warm up otherwise it will cough and splutter before I can drive.

I have set the idle co level, changed plugs, lead, caps etc and cannot see any vaccuum leaks.
My next suspicion is the o2 sensor, although the cat has been removed.

Im sure this must be an air leak issue but cannot see anything.

 

[carat 3.6]

If you suspect a vacumm leak, brake cleaner will find it. With the car running, spray it in short burst's around the inlet side of the engine till you hear the engine note flutter. This is the brake fluid being sucked in, and should help you to find the leak.

Hope this is helpfull.

Ps- have you checked to see if the cold start injector is working?

 

[jaymanek]

No I haven't checked yet, will do that tomorrow.

 

[jaymanek]

twas the OVP relay! Shouldve known...

 

[mazza]

Guys my estate is running rough when cold and also is hard to start. How does the cold start enrichment work?


Hi J

When you turn the ignition on, the ECU takes a reading from the coolant temp sensor, if temp is less than (if I re call it correctly) 34deg c, the ECU grounds the thermo time switch which is attached to the Cold start injector (Looks like a normal efi injector harness). the Thermo time switch activates the cold start valve for 5-12 seconds.

The harness can go wrong sometimes

check if the cold start valve is actually spraying when you turn the engine

mazza

 

[Martyn_n]

Fit a couple of turbos, that should do it!!

 

[Alex Crow]

twas the OVP relay! Shouldve known...

Sorry I came to this thread late, but I was screaming out OVP to my keyboard until I saw it had been sussed

These KE-jetronic engines will run surprisingly well with the ECU unplugged, at least when warm. The OVP relay supplies power to the ECU, so there you go...

 

[jaymanek]

Yes I thought it was placebo when i got in the car and it felt like a rocket compared to before... must have been faulty since I bought the car.