After TDi head job

**dafydd** · 29-12-2009,12:14 PM

Hi there,
I hope someone can help me with this one, over the summer i went to town on the car, new suspension interior etc etc, when i checked the egr valve it was thick with black treacle thingy, so i took off the manifold to clean the lot out, but the head ports were bad as well. In the end i took off the head and also cleaned that, did the valves and seals. when i was rebuilding it i decided to change the vacuum hoses seeing that a few seemed a bit worse for wear, the problem I'm having is that the car seems to have lack of power, not to bad really but there is a lack of power there, I've got a puma power box fitted for a bit of fun, but I've disconnected it for now, until i can get to the bottom of this problem, every thing seems ok, no fault codes and nothing hanging off etc, the diameter of the vacuum hoses looked the same, i think there were 2 different diameters,
many thanks for your time.

**Crasher** · 29-12-2009,12:22 PM

Golf 4 TDI what?

**dafydd** · 29-12-2009,02:08 PM

hello crasher, its a 1.9 GTTDi 110 bhp engine code ASV,

**Crasher** · 29-12-2009,02:25 PM

With no fault codes, no power and assuming everything is correctly connected and the valve/pump timing is correct then the first thing I would do is to change the Air Mass Meter for a genuine VW exchange unit supplied by a VW dealer, no not buy one anywhere else.

**dafydd** · 29-12-2009,02:44 PM

i did think of the mass meter, so i disconnected it and went for a spin, there was a huge power drop. this mass meter I've got on is new ish, not OEM but Bosch, so i suppose the mass meter is OK seeing after i reconnected it she went fine again, she just feels a little flat and not a power drop really, would an oem meter make a difference?

**Crasher** · 29-12-2009,02:48 PM

I don’t find the disconnecting of the AMM ever proves anything for me. I only fit genuine AMM’s as I have so much trouble with those from other sources. I was pushed into fitting a non genuine unit a couple of weeks back, it ran worse than the one I took off. I ordered and fitted a genuine unit and it was perfect.

**dafydd** · 29-12-2009,03:06 PM

I understand where your coming, I normally fit OEM or better(if possible) but i thought Cant go wrong with bosch, but when i disconnected mass meter there was a big difference in the power, but saying that maybe its not working as it should, i think ill give the local vw stores a tincklem, me thinks and try an oem meter, ive spent quite a bit there over the summer, i now get at least 10% disscount, not much i know, but better than nawt

**dafydd** · 30-12-2009,07:34 PM

well, ive changed the mass meter with a an OEM from the local VW Dealer, and theres no change, i forgot to say that ive had the injectors done aswell, the old ones were quite worn, so the local injector specialist told me, i did put a note in with the injectors saying engine number and 110bhp, could it be a leak on the turbo side? the car will accelerate quite well up to about 80 and the tends to die off and not really struggle to 110-120, but it could be better, its just feels thats its lacking something

most annoying.

**Crasher** · 30-12-2009,09:37 PM

The next step would be a drive with VAG-COM/VCDS on the car and log the requested and actual boost pressures. When the cam belt was fitted, how was the valve timing set?

**dafydd** · 30-12-2009,11:04 PM

when i changed the cam belt, i locked the injection pump with a locking pin, i centralized the camshaft with the bar and inserted feeler gauges on both sides, and i lined up the crankshaft with the mark on the flywheel, after i started the engine and checked for leaks etc, i rechecked the timing and it all lined up perfeclty, theres no excecive smoke or poor idle or erratic running, it starts up no problem, its just the accelaration is not how it was, i still havent got round to getting the ross tec softwear, but im gonna have to get round to it when ive got spare cash.