vr v6 starting problem

[itsavr]

my vr v6 has a bit of a problem starting after its warmed up some times when cold it will wind over for about 15 seconds or so and when it fires it misses and runs rough or some times stalls and back fires thourgh the thottle body, but after a 20 seconds it comes right and i havent lost power or fuel economy, but if i turn it off and start it again its fine, ive tried alot of different things like removing the whole intake manifold and cleaning it, plugs leads filters and so on and nothing comes up on computer diagnosses, can any one help me?

[vps_are_the_best]

Timing Sounds like its out. Also ake sure You are running the right plugs and Resistance leads. Try Checking the Ignition Coils.

[Brett_jjj]

The timing can't be changed manually on a V6 engine.It is controlled by the ECU.Its base timing is 10 degrees,which is also set and can't be changed.So Id be looking at the coils ,test their resistance etc.And maybe get the fuel system pressure tested to make sure its ok.

[hako]

I'd also check out the fuel system - when you turn the ignition on you should immediately hear the fuel pump run for a second or two, this primes or pressurises the fuel rails so the injectors can squirt fuel into the manifold. If this isn't happening, but the car eventually starts, then it is possible that this 2 second prime is not happening. What may be happening is that you have no initial prime from the ECU when you turn the key, but 15 seconds of cranking raises the oil pressure switch enough to allow it to power the fuel pump. Once the car is running and you then try to restart, the car will start instantly as the fuel pressure remains in the fuel lines for a few hours.
I'm not sure exactly why sometimes the ECU fails to turn the fuel pump on for a second or two to prime the system....maybe it's to do with the immobiliser.
But, the bottom line is next time you go to start the COLD engine, listen as you turn to ignition for thre fuel pump to prime/run for a second or two......if you don't hear it then the fuel lines have no fuel for the injectors to...inject.
I could be completely wrong but I just suggest the above as a possible cause.