Cold starting not so good.

[MK21800]

Scala Injection - used to start immediately within one or two revs, nowadays if it's been sitting for a few days, it takes 3 - 4 seconds to start (although it always starts), slight smell of petrol for about 5 seconds.

Leaky injectors? Injector seals? Cold start injector?

It's had new plugs, dizzy cap, rotor arm and ht leads (although it had this issue before I replaced them). The petrol smell leads me to thinking slightly leaky injector maybe?

Or yeah and from cold start, pumps out a little bit of smoke from exhaust for about a second (white, not blue).

Thoughts?

Warm starting is fine, no petrol smell, and immediate, no smoke from exhaust.

[mark1gls]

White smoke from exhaust is normal and just condensation burning off.

I would guess it’s leaking injectors, does it run a little lumpy when it starts?

You could also try and unplug the electrical connector on the 5th injector to stop that adding more fuel when starting from cold.

They only way to test the injectors is pulling them out and seeing if they drip after spraying fuel.

[MK21800]

Actually, no, I'm pretty sure it's quite smooth when it starts. It kicks straight in to life. I will double check next time I start it up though.....

Thanks for the reassurance re. the condensation out of the exhaust, it did cross my mind this is what it looked like - water vapour.

I've been watching some stuff on Youtube with guys doing the K Jetronic thing with four containers and lifting the airflow sensor, measuring the fuel, checking for drips, and replacing the seals etc - I've not done this before but looks like I'm going to have to commit to giving this a bit of attention in that respect. I'm on 115000 now and I doubt this has ever been done on this car.

Also, I'm wondering about tuning - MOT gives me good emissions. However,I wonder about timing and CO2 adjustment. Perhaps worth having a look at.

[mark1gls]

What’s the air filter like?

[mark1gls]

To start fuel injection cars by the book… turn ignition on (lights on dash) and don’t touch the accelerator wait a few seconds (I wait for the red water light to stop flashing) then turn the key to start without touching the accelerator.

How are you starting the car?

[MK21800]

I was starting it like that, except I have never waited for the water light to go off, just crank and go but without any gas.

I tried earlier and disconnected the blue switch from the cold start injector and started it like you describe. It was slightly better, starting within about 2 seconds, but I have to correct myself from a previous post - it is actually very lumpy. Never really noticed that much before, from a combination of not paying attention and the rev counter being bust.

It's lumpy and sways around on the idle. However, after the first pump of the throttle, it settles down and runs nicely.

Just for the record - I replaced the inlet manifold gasket and bolts (they are the proper locking type), throttle body gasket, and cleaned the throttle body a few years ago. it ran perfect after that. So I'm doubting it's an air leak around there.

Bumped into a mate of mine earlier who's quite handy and he agreed - possibly leaky injector, or injector seals need replacing, looks like I'm going to have to whip those out at some point.

Can I check something - when are we meant to hear the fuel pump priming / buzzing from the back? Is it when we're in the ignition position or is not until we crank? I knew this when I had to replace a fuel relay but it was years ago and I can't recall....

thanks for your help as always mate.

[mark1gls]

It does sound like leaking injectors if it’s lumpy on start up and clears it self after a rev, that’s what mine started like and I ran without the 5th injector for about 12 months before changing the injectors.

There is 2 types of injectors and I guess you have the air shroud injectors if you have an air hose between cylinders 3 and 4 at the back of the head near the injectors?

Just be careful removing the injectors as the air shroud injector have a “top hat” on the end which can fall off, try and pull them out as straight as possible, a bit of wood on the engine and something to lever them out the first few cm then they should come free.

I’m on my 3rd set of injectors as I’ve found after about 100,000 miles they need replacing but check them first as the price of them has gone up a lot !

The fuel pump priming - it all depends on what type of fuel pump relay you have, an original VW No. 62 relay will not prime the pump before starting the car, an aftermarket one may prime the pump for a few seconds when you switch the ignition on (lights on dash) and I think some other number VW relay may prime the pump before starting.

Waiting a little bit with the ignition on before starting car can help as it gives time for the WUR to heat up and increase fuel pressure.