Starting Problem...

[KRISKARRERA 2 1 Cars]

...but I like to return to it now and then lol.

 

The engine starting up behaviour of my engine has always puzzled me.

 

When the engine is stone cold it will start instantly.

If it's been run just a short time ago, say 10 minutes ago, it will restart instantly.

But anything else and it will take a good 5 - 10 seconds to start - doesn't sound like long but it still shouldn't take that long. So it's definately a temperature related problem.

It's also jerky when going on and off the throttle. Particularly at low revs. So let's say I'm drifting along in traffic doing 2k rpm in 2nd and then I gently hit the accelerator what will happen is there'll be a split second loss of power and then the power comes on with a jerk, and then it goes again and then it comes on again and stays on. The same happens coming off the gas - it behaves like I've taken my foot off accelerator but fuel hasn't instantly stopped and is still slowly seeping out of injectors.

Performance is great elsewhere, revs up to zillion revs without complaint.

Oh you know when the engine is above idle speed the fuel is cut? Well is the engine still sparking?

I had wondered if it could be the ignition amp. So I did a test. I ran the car up to temp and stopped it, bunged the amp into the fridge, got it nice and cold, and stuck it back on engine and restarted engine. Didn't restart any quicker so it's not that.

Spark plugs and dizzy cap and arm are new. HT leads are old - but if they were dodgy wouldn't they be causing problems all the time?

 

Anyone ever had this before?

[ryan13961345402285 1]

I had a similar problem with my old Metro Gti. It was a dodgy temperature sensor (that gives the signal to the ECU)

[tzracing 0]

I had similar problem on my MI16.

 

We found that was the ignition amplifier module. It took several weeks to find out until it does not start anymore...

just a tip...

 

[KRISKARRERA 2 1 Cars]

Thanks for that mate.

Incidentally when I drove the car earlier it misfired/kangeroo'd so badly it was undrivable.

Left it for an hour or so and it was fine!!