Pt 2 cold starting problem - Is my ECU the problem??

[manfred]

In part 2 of my VR's starting problem, could it be my ECU the main crutz of it all?? The car starts with no problems after the battery was replaced and also when battery was disconnected and then reconnected giving time the ECU to reset.

 

[kopper69]

ECU is normally pretty reliable. Are you saying shes running fine now?

 

[DannyboyDS]

No I think they are saying that it starts like crap, unless they reset the ECU then the first start is ok.

I'd assume another compnent is faulty and the ECU after being reset starts the car on a basic setup, then the faulty component sends it its signal or lack there of, the ECU tries to adjust and creates a problem.

Although then an error code would be logged.

 

[andyman]

take it for a long run like a 50 to 100k trip and see how it goes, i know with mine you have to take it for a good drive after disconnecting the battery for it to re adjust its parameters,

 

[manfred]

Could it be the actual Harmonic Balancer causing the problem in cold starting?

When my car went in for a service, the mechanic found a crack in the harmonic balancer. I don't know where on the harmonic balancer but he says it is there.

 

[ephect]

what exactly is ur "part 2 problem" ??

u havent listed what its now doin? i've read up on ur first issue and u said that it had been fixed?

is it still taking 5-10 secs to start? is ur car running like crap? u havent said what ur problem is? we need as much info to help us help u

what makes u think the ECU is at fault?? it could be a part thats failing, that makes the ECU run in limp home mode.. then resetting it, clears the fault code, making it run normal, until the faulty part logs a code again..

 

[kopper69]

Grab a manual mate and have a read. Will hopefully point you in the right direction. Even if it doesnt solve you problem, should help you check just about every component. Theres no point guessing is it ecu, is it harmonic balancer - youre clutching at straws.

 

[manfred]

I came to a conclusion that my ignition on the steering column is the prob 'cause for the 1st time in a long time I heard the fuel pump buzzed (fuel got up to pressure) and the car fired up with just a flick of the key today (24th April 2007). And to be sure I done it a couple of times and again a flick with the key and it started straight away. Also noticed that my engine check light didn't flash once and lit up, but lit up only once before starting.

 

[304cci]

engine coolant temp sensor?
On cranking the ecu looks at the coolant temp sensor to decide how long and fast the fuel injector paulse should be. If it is incorrect the air fuel mixture will be incorrect for a cold start, and it will flood.

 

[manfred]

Had my mechanic look at the cold start problem on my VR commodore V6 and he came to a conclusion its my EFI relay causing the problem due to the fuel pump not getting the correct voltage through the relay contacts so that the fuel pump makes a whirl noise in the fuel tank, giving the correct fuel pressure in the fuel rail before cranking over the engine.