HI all,

Hoping someone can shed some light as I'm desperately out of my depth. My car is a 2004 Skoda Octavia 1.9 TDi 110 81kw asv 1u5.

After a head gasket replacement and timing belt change, I'm trying to set the timing using the graph in VCDS. No matter what I do with the pump, the graph will only show 38 and on the bottom it says "timing within spec: slightly retarded. Nothing I do changes that.

I have adjusted the pump to retarded where it won't start and advanced where it clatters. I've tried in between those points but can't change that graph from 38.

The car drives well enough but has some slight hesitation under 2000rpm but fine after that. Idle is a horrible, feels like the engine wants to shake itself out.

I believe my G81 fuel temp sensor is lazy so I'll be changing that when the triangle bolt tool arrives.

I had the injectors refurbed. I've tested the needle lift wire and get a resistance reading of 117 so that's fine from what I've read.

I have a very low injection quantity reading which bounces from 0 to under 2. I tried changing the adaptation number but that didn't make much difference. When I first looked it was set to 32668. I've read the iq number should be between 3 & 5 and the "hammer mod" may be required?

I've wondered if I'm a tooth out on the timing, but AI says the car wouldn't run if it was a tooth out.

Any ideas on where to look and what to check would be massively appreciated.

Cheers

On the 1.9tdi BXE the camshaft pulley has three bolts in oval holes. When I did mine I had to loosen and adjust slightly. First I used locking tool kit and fitted belt then removed kit and rotated engine by hand but after a full rotation I had to adjust bolts slightlyt to get timing locking tools in again. Wasnt much probably 1mm but it may be enough to affect timing. Think they will run if only one tooth out but would be very noticeable. If its just slightly out by 1mm it may explain your problem.

Alasdair

Hello mate,

There no adjustment on the camshaft on mine, you lock it from the end where the vacuum pump sits.

So being is screwing with my fuel and I don't know what

Not familiar with that engine. All mine were 1.9bxe but had a quick look online and if the G81 sensor fails or the needle lift sensor (yours reads within limits) the car reverts to default 38. If its not the G81 then may be wiring damage somewhere to either.

Dont really trust AI but it came up with this to check G81

1. Check Group 007 in VCDS (The Live Data Test)

Before buying parts, let VCDS tell you exactly what the G81 is seeing.

• Connect VCDS, turn the ignition on (engine off or idling).

• Go to Engine (01) -> Measuring Blocks (08) -> Group 007.

• Look at the field labeled Fuel Temp.

• The Verdict: If it reads an impossible number like -40.0°C or 130°C+, or if it doesn't closely match the ambient temperature of a cold engine, the sensor or its wiring is dead. The ECU is using a hardcoded fallback value, which locks your timing calculations.

At this point its getting above my comfort zone.

Alasdair

I'll be changing the fuel temp sensor hopefully Monday.

I hope it's not worrying, 5 minutes totems into 5 hours.....