Engine response delay

[Lewi]

I just bought a Mk2 GTI with an ABF 2.0L 16v engine swap. I was told that its running a digifant 3 injection system. i feel that the engine response is a bit delayed. Im not sure if this is normal but it doesnt feel like its normal at all. Theres is at least a 2 second delay in throttle response and im not sure what is the problem.

It would be great if anyone can help me identify the problem for the delay in throttle response. The engine seems to cut out a lot because of this problem. Thanks

[mikinoz]

Hi mate, welcome.

Whose car did you purchase, was it one from the forum?

There should not be that level of delay, it sounds un-driveable.

Get some more details and pics up and we can give you a hand.

Mick

[Lewi]

Yep, i bought it from this forum. It seems that i have to rev the engine a little more just so that it will not cut out when i ease of the clutch. I would try to rev it every time it is about to cut off but it always responds just a bit too late. It can be compensated by revving it more at before the clutch but its a annoying. Btw did you sell you car or are you looking for another project cause it looks like your doing a major clearance mick.

Heres and engine picture from the post. Dont have one of my own yet, havent had the time to take photos


Lewi

[peedman]

Perhaps you have a vacuum leak somewhere? Does it do it all the time i.e. when the engine is hot and cold?

[Lewi]

Well i bought it very recently and havent had the time to take it for a long drive yet but it does it when its cold, not sure about hot.

[mikinoz]

Lewi, I am indeed clearing out, moving on all my stuff which won't go on the current white car - as I am pretty certain this one will be my last Golf.

I hate to state the obvious but what happened on the test drive and did this happen for the previous owner?

I tend to think Pedro has a point, there are a number of other things such as idle stabilisation valve that could contribute but it is really hard to know without hearing/seeing it happen.

[Lewi]

The car was alright but i didnt notice it until i was shifting it into my garage which is a bit narrow to get into with an incline and the car started to stall a few times, thought it was my issues with controlling the clutch but when i revved it to double check, its seemed a tiny bit delayed. I should be able to check the car again tomorrow to try and solve the problem. Might take a video of it running tmr just to show the engine running.

[RedMk2Gti]

I tested drive this car as well, I did notice that it response bad when cold, once it's fully warm up it runs perfect.
If you're stuck I suggest you bring it back to who built this car, camden GTI aka Golfloon in this forum, he should be able to sort it out.

[peedman]

If it only does it when its cold then it could point to the ISV. It should be buzzing when you first start the car, unplug it and see if it makes any difference. I would also give it a good clean and soak it in petrol/clean with carby cleaner then give that a go.

If you need a spare one i do have one but unless you really need it im trying to hang onto it as its very uncommon part.

[Lewi]

alright, thanks for the help! i will go check it out and see if it make a difference.

[mikinoz]

I would also give it a good clean and soak it in petrol/clean with carby cleaner then give that a go.

Subaru Upper Cylinder Head treatment is also very good for this.

[Lewi]

I had a bit of time to feel what was wrong with the engine,it seems i was wrong, it isnt so much as a throttle delay as it is the idle problem. It's normal idling rate is at about 800-1000 rpm but every time the throttle is pressed or even just feathered, the rpm dives down below 800 for about 2 seconds the moment the throttle is released before it recovers to it normal idling rate.

[mikinoz]

Is the air conditioner on or off? Sounds like the ISV or a vac leak now for sure.

[Lewi]

Happens both when its on and off if i remembered correctly. Also, i dont know if this helps but there is that buzzing sound that you mentioned when the ignition is on. Im a bit clueless about the digifant system of this engine. The whole concept is a bit new to me so im not very sure about this engine myself.

[rutti]

Hi Lewi,

I just started my 1.8L engine recently (after months of engine work) and noticed the same phenomenon. I have replaced all vacuum lines, so I will be checking my ISV or idle screw (for leaky oring) next. Will keep you updated once i get round to that this weekend.

---------- Post added 06-11-2011 at 10:27 PM ---------- Previous post was 02-11-2011 at 09:04 PM ----------

I swapped another isv which I have cleaned up with carb cleaner today. It's running sweet now!