Mk2 8v block with abf 16v head stalling problem

Hello, I have a mk2 GTI 8v with the abf 16v head conversion, whenever I start the car I have to give it gas then once its started I have to manually hold the revs otherwise it will stall out. It can stall out at any time when I am coming to a stop or using the clutch. When it is warm it idles a bit nicer but it very shaky and moves around the rev range and still occasionally cuts out. Any ideas what it could be? I have changed the ICV and my friend has suggested the inlet air temp sensor, I hope you can help.

Sorry if this has been covered or is in the wrong area, I couldn't find anything specific to my problem.

 

that must be really annoying...

have you checked your coolant temp sensor and for vacuum leaks?

 

There is a little nipple on the top left of the inlet manifold and it is open to the air, I can feel it sucking air in but when I block it and drive it makes the problem even worse. The car will stall every time I stop.

Yes it is very very annoying especially since it is my daily and sitting in traffic stalling every 2 mins is not fun.

I have had a quick check to see for vacuum leaks and have found nothing. Where would the coolant temp sensor be? Would it possibly have moved after the head conversion?

 

is it running the abf intake manifold? and are you talking about the nipple just to the right of the throttle body? if so this goes to the ECU on an abf engine, could be the source of your issues - anyone else can correct me if i am wrong!

Did you swap the heads yourself or was it something you inherited?

coolant temp sensor on the ABF head is on the right hand side underneath the dizzy!

 

Yeah that's the one. Yeah top right of the throttle body. I have seen some pictures of abf's with that port plugged?

I bought it that way as I was told it was a full mk3 engine swap but they were wrong.

Since it's the mk2 8v block would it be a different place?

 

sorry thats as far as my expertise (trying to sort my own mk2 abf knowledge) can help

hopefully someone with some experience can chime in

 

Fair enough, thanks for the info. Hopefully someone else can shine a light on the situation

 

my advice would be to change the thread title to something a little more descriptive with regards to change in head etc, might get more attention

 

As the engine is a bit an unknown factor with the head / piston swap ? .....
maybe best to do some basic checks.... compression, timing-belt timing, ignition / sparkplugs....

 

8v bottom end with 8v pistons, running which ECU?

 

As far as I'm aware it's 8v bottom end with 8v pistons with the corrado 2l ECU.

Timing ignition and spark plugs are all okay. They were checked when I had my last problem.

 

If you're running 8v pistons with a 16v head you'll have between 6.5-7.3:1 compression, and factor in there's no valve relief in the Pistons which could cause issues then I'd say this is the problem.
Looks like you're going to have to do some investigation into what you actually have under the head.

 

As per hotgolf.

Was this an experiment for turbo charging?

Was it actually working without a problem before?

 

In these earlier ECUs it wouldn't throw up a fault code would it? I have the guys number who did the swap so I'll ask and get back to you on that one.

Surprisingly not, I don't know how far I could push the rods if I stuck a turbo on it so I haven't bothered trying.

When I got the car about 4 months ago it did have to start with a bit of gas and once it started you had to hold the revs a little but it would idle fine and once it'd been working for a few mins it wouldn't stall out. The problem has slowly started and hot worse.

I got a suggestion of checking the throttle body?

 

Now the guy is saying it's a full Abf engine. He has confused me and himself I think. It isn't letting me post any pictures from my phone so I'll try when I get to my girlfriends in a few hours. The ECU part number is 037 906 024 AE

 

ECU part number is an ABF ECU indeed.

Just to confirm what the engine is.

 

Thank you. It's good to be sure

 

https://mmi402.whatsapp.net/d/uHqBl...fY0PGff9zgzY-v8vwUZ-sQF1iADpPl1Nnt1LscBM8.jpg
https://mmi432.whatsapp.net/d/wOh2T...fT0FFKKTxaASjW6OoL52QOtguw5IqsoqA19HAsXEB.jpg
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https://mmi670.whatsapp.net/d/eD5nc...vWkBO0pFYBQNKzk0isOL2d8qeW4E17YFTJTr913cH.jpg
https://mmi287.whatsapp.net/d/U18jz...pLYxBecjnCtb19Jxa-2imlRNBGRRfBUhFVkQ3vjX8.jpg
https://mmi687.whatsapp.net/d/CnqTb...tSTL9lMTKp2qTPV6loqxWKNksknWCGLQmVDgJhuJ7.jpg

There's a few photos for reference

 

Hmm, not working for me.