Booki

Hey all.
I recently bought a 2001 Holden VX Berlina LS1. Had a few hiccups with it, but thats life

Cold starts, no worries. Hasn't let me down yet. Fires straight up.

The issue seems to be if i have been driving, let it sit for about 30mins to an hour or two (can't be super specific about the time as it varies), come back and she won't fire up the first go. It will crank normal speed (so i assume battery/starter's are all fine) and fire but have a horribley low idle then just stall....then you have to crank it for about 5 seconds before it fires again, then runs fine.

I am no mechanic by any means, but i have a feeling it might not be getting fuel...or maybe too much? :\ Thinking maybe a reg, bad injectors?
Car drives fine, which is what i am unsure what part to replace.
No error codes on the ECU either.

I took some video's to when it starts up normal and when it doesn't.
The last one is what i am trying to describe..

See what you think fellas!

Normal Start - Normal Start - Bad Start -

pat-ls101

I would test the fuel pressure when it does that. You could have a fuel pump going south. Or relay etc.

But, first things first, test fuel pressure.

Booki

Thanks for the reply pat,

I am leaning towards injectors leaking.

It never does it on cold starts, only if its been sitting for a little bit.

Thinking fuel may be leaking and flooding the motor, the oil also smells a bit like petrol...

Regardless, bought some new injectors and will see how it goes.

wssix99

iTrader: (5)

Looks like the coolant sensor and/or circuit. Take a look at your video on the bad warm start. The car thinks its cold when in reality, its really warm - right? The normal start video shows that the temp gauge goes and is reading the temp before the car cranks.

Booki

If that where the case. I should be able to shut my car off when warm. Leave it for 30 seconds
Start of again and it should stuff up...but it doesn't. Wouldn't that rule out the coolant temp sensor?

wssix99

iTrader: (5)

Its not necessarily the "sensor." It could be an issue with the circuit or something else in the system. The videos you posted seem to correlate to inaccurate coolant readings. You might take note of this for a while and if your gauge continues to show "C" during the hard starts, that would continue to point the finger.

This has some good info: http://www.google.com/url?sa=t&rct=j...46751780,d.aWM

You might also check for air in your system. (If your sensor isn't in contact with fluid, it won't read correctly.) When you take the radiator cap off with the engine cold, is the fluid level at the top?

Booki

After re reading your post,
I do not claim to be any expect but...

Even if that were the case, it shouldn't squirt so much fuel to flood the cylinder to cause hard starting.

Cold/warm start configurations for fuel injected cars shouldn't be that much different.
I understand on a cold motor it will get more fuel to make starting easier, but getting more fuel on a warm motor should not make that much a difference surely?

Because if i give it gas while it is on the bad start, it will fire up (which i assume gives it even more fuel?)

Could my injector theory even be a possibility?

lt1pwr1

iTrader: (1)

wssix99 is correct.

A bad circuit on the coolant temp sensor can most certainly cause hard starting issues when the car is warmed up.

If you lose the circuit and the reading is pegged at -40, trust me you will have a long crank with the car warm.

Do you have a scanner? Can you take a look at the reading from the coolant temp sensor after the car is warm?

Booki

I have a ELM 327 usb cable, which I have used with ProScan 5.9.

It lets me clear engine codes, but I don't think it reads the data accurately on my car.

RPM's are all over the place

wssix99

iTrader: (5)

I have the same problem often because the OBDII interface is so slow (1990's serial technology) that it doesn't mesh with faster connections, like USB. I had to use a different type of application and de-throttle my app in order to get better data.

RPM WS6

iTrader: (3)

I agree.

Excess fuel from a misunderstanding between the CTS and the PCM can certainly result in warm start issues - for the same reason that a dripping injector could/would (which was your initial assumption earlier in the thread).

If the dash needle is showing "cold" when it should be showing "warm", and these are the only times you're having start-up issues, then I would certainly look into this before spending the money to replace injectors.

Also, keep in mind that when you open the throttle (usually 80% or more) during cranking on most EFI engines, you will enter a "clear flood mode" that will greatly lean (or end) fuel deilvery to the engine until you release the throttle or rpms come above the typical cranking/idle speed. So while you might think that you're giving it more gas by pushing the pedal down while cranking (which would be true if there was an accelerator pump), you are actually leaning things out. This method would be helpful whether the rich mixture was due to poor CTS input or a dripping injector.