starting from cold help pls?
Moderator: martauto
325 cab, i have a slight problem when starting from cold it doesnt seem to want to fire up properly, it goes to fire but does kind of catch/run if you sort of understand me, but when you touch the throttle a bit it seems to help it, but when started with help from the throttle it will run a bit lumpy for the first few seconds, a bit like its flooded up then it will clear and be fine all day, no problem at all when warm? any ideas
Had/have a similar problem with my 320i - poor cold start, fine when warm. Good luck, there's a whole list of things it could be....
But here's four things to check that cost nothing:
1) run a jump lead from the negative terminal of your battery to the lift point at the front of the engine. If it starts any better, your engine earth strap could be knackered (it runs from the sump to the passenger side wing) Check, clean and/or replace.
2) Check the TPS (throttle position switch). With engine off, open the throttle by hand from its rest position. You should hear a click from underneath the throttle body. This is the switch moving from idle position to running position, which ultimately changes the mixture. My throttle screw had been wound in, so the idle was higher (presumably to cover some problems), the result was that the TPS was never at its idle position. There's a multimeter test you can do as well (lots of posts on this in the archive)
3) Consider the simple 'spark' side of the equation. How old are the plugs, dizzy/rotor, battery etc? are all the leads in tight and tidy etc
Anything that makes the car harder to start gets worse from cold, and much worse from cold in the winter. If it doesn't fire up quickly as a result, my Motronic seemed to flood very easily, and so it went on
4) On the 320i there is a circular block connection located a bit below the throttle body. It unscrews from the bottom. Mine was fine, but apparently water collects under the rubber boot, rotting important wires. Worth a squirt of WD40 if nothing else. Same goes for all the connections you can see (ICV, Airflow meter, the pair that plug in under the big round diagnostic thing....)
I'm just a novice, but based on my recent experience, I'd look at all these things before getting involved in blue temp sensors, ICV, fuel pumps etc etc
Oh and I think it helps to 'prime' the thing before starting - turn key to position 2, count to five, then try and start it.
Good luck
Alex
But here's four things to check that cost nothing:
1) run a jump lead from the negative terminal of your battery to the lift point at the front of the engine. If it starts any better, your engine earth strap could be knackered (it runs from the sump to the passenger side wing) Check, clean and/or replace.
2) Check the TPS (throttle position switch). With engine off, open the throttle by hand from its rest position. You should hear a click from underneath the throttle body. This is the switch moving from idle position to running position, which ultimately changes the mixture. My throttle screw had been wound in, so the idle was higher (presumably to cover some problems), the result was that the TPS was never at its idle position. There's a multimeter test you can do as well (lots of posts on this in the archive)
3) Consider the simple 'spark' side of the equation. How old are the plugs, dizzy/rotor, battery etc? are all the leads in tight and tidy etc
Anything that makes the car harder to start gets worse from cold, and much worse from cold in the winter. If it doesn't fire up quickly as a result, my Motronic seemed to flood very easily, and so it went on
4) On the 320i there is a circular block connection located a bit below the throttle body. It unscrews from the bottom. Mine was fine, but apparently water collects under the rubber boot, rotting important wires. Worth a squirt of WD40 if nothing else. Same goes for all the connections you can see (ICV, Airflow meter, the pair that plug in under the big round diagnostic thing....)
I'm just a novice, but based on my recent experience, I'd look at all these things before getting involved in blue temp sensors, ICV, fuel pumps etc etc
Oh and I think it helps to 'prime' the thing before starting - turn key to position 2, count to five, then try and start it.
Good luck
Alex