Hot starting issues

[The1]

Poor some cold water on the cas when it does it, if it starts straight away then its cas

[slewinson]

Thanks the1 for the suggestion. Will try it and see what happens.

Simon

[slewinson]

Have had a further look at the data and now think that it is not CAS related. Both starts show 0.4 secs of cranking to get a valid RPM value. RPM rise rate is identical for both starts at this point but RPM drops with the bad start, plateaus and then rises bumpily after another 2 seconds of cranking. Spark advance and IAC are consistent between starts too. MAP and injection quantity are also consistent.

I am leaning towards a dribbling injector and thinking of simulating an overfuelled start by putting in some fuel from cold and seeing how it behaves. Thoughts?

Simon

[vlad01]

here is my test for that. run the engine until operating temps.

remove the fuel rail, wipe clean the injector tips. Presurise the system with ignition on. Watch the injectors, even use paper on the tips to show wetness.

Keep re-pressurizing the system every so often as it can loose pressure via a leaky check valve in the pump.

You should see a slow weep to dripping dependent on how bad it is. You need operating temps as they often leak when hot and seal ok when cold I have found.

[Holden202T]

or remove the fuel pump relay and short it with a jumper wire to keep the fuel pump running

[slewinson]

Will look to do that over the christmas break. I like the paper idea for detecting seepage.

While in Melbourne I might try and get a cheap set of spare injectors.

Simon

[Charlescrown]

Have you thought to pull a plug out after the cranking problem to see if it's wet?

[slewinson]

Was a at the back of the car today when the other half started it and it stinks of fuel till it gets running so it looks like a dribbling injector. Now to try and get another set to swap in. Will probably look at getting them cleaned beforehand.

Simon