1.8t hesitating under full throttle

[noj]

On the way home from the nationals I overtook a car in 5th gear and the engine seemed to lose power and splutter until I backed off the throttle.

I tested this several times in different gears with the same result. Seems to happen only under 3500 revs under full throttle? Once the revs get up it goes fine.

I'm running BP 98 octane fuel. Will do a VAGCOM scan asap to see if any faults show up.

Has anyone experienced this?

[BB]

Id pick leads need replacing. I have just replaced my little ladys leads on her 16v KR motor and it started missing about 2 months later! It was the spark jumping out the side of the lead. I just wiggled and wiped it.
I think tho actually your car will have coil packs and they crap out with great regularity. They start arcing a hole through the side of the insulation.

[RS ZWEI]

On the way home from the nationals I overtook a car in 5th gear and the engine seemed to lose power and splutter until I backed off the throttle.

I tested this several times in different gears with the same result. Seems to happen only under 3500 revs under full throttle? Once the revs get up it goes fine.

I'm running BP 98 octane fuel. Will do a VAGCOM scan asap to see if any faults show up.

Has anyone experienced this?

If it was the other way around John (hesitating up high in the revs) Id say fuel filter or fuel pump. Since its the other way round Jem could be right with the leads being the issue.

Let us know how you get on with VAGCOM.

[vag_nutter]

Dont 1.8t have cop so theres no leads

[80 Vert]

Have had MAF sensor cause low rpm hesitation, and yes 1.8T has coil on plug.

[Jetta CLI]

Have had MAF sensor cause low rpm hesitation, and yes 1.8T has coil on plug.

had the same problem then replaced mine about a month back and its sweet again, mine is not 1.8t though

[tonka]

On the way home from the nationals I overtook a car in 5th gear and the engine seemed to lose power and splutter until I backed off the throttle.

I tested this several times in different gears with the same result. Seems to happen only under 3500 revs under full throttle? Once the revs get up it goes fine.

I'm running BP 98 octane fuel. Will do a VAGCOM scan asap to see if any faults show up.

Has anyone experienced this?

my mk3 16v did this.
mechanic said that the wrong spark plugs were installed, and so he just put some more powerful/correct ones in and then boom - problems solved

[veedubman]

Have you thought about the Ignition Amplifyer.. the damnin stupid Pluggy thing in the side of the Airbox.. that causes issues also..

most of these dont even show on vag com...

[noj]

Will look into some of these ideas, thanks. Green coolant temp sensor has been recently replaced, as has the MAF sensor.

[noj]

Did a full scan with VAG COM tonight, no fault codes came up. Might have to drop the car into the VW shop and get them to have a look, thinking it might be the coil on plug system?

[BB]

If the coil on plug fails it just causes missing all through the rev range.
What about this ingnition amp that Anton mentions? He is quite clever really.

[veedubman]

Im wondering if your crank angle sensor maybe on the blink...

that can cause cut power if it isnt plugged correctly.. but then again that one would showup over any of the others... try and borrow a working Ignition Amp (the thing in the side of the airbox)

You may have ended up with a Faulty MAF thou.. people seem to forget that parts that are out of the box.. can actually be faulty...

[BB]

But A faulty MAF would show up on the vag com scan wouldnt it?
Did you check the vacume line thaat goes to the ecu? If there is one, In brendons 16v it pulled perfectly to 5k then cut out, he put the hose back onto the ecu and it was fixed.

[noj]

I took the car to the VW service agent yesterday for an oil change and to have a look at the above problem.

What they thought was that the turbo was overboosting, and are waiting to hear back from Superchips UK for some info.

I'm not convinced this is the case, surely it would show in their VAS program?

After a quick read on some forums it looks like a lot of chipped 1.8t's are running N75J valves.

[veedubman]

I took the car to the VW service agent yesterday for an oil change and to have a look at the above problem.

What they thought was that the turbo was overboosting, and are waiting to hear back from Superchips UK for some info.

I'm not convinced this is the case, surely it would show in their VAS program?

After a quick read on some forums it looks like a lot of chipped 1.8t's are running N75J valves.

all 1.8t have N75 J valves?


Ur hesistating will be coil packs or ignition module or MAF

[noj]

all 1.8t have N75 J valves?


Ur hesistating will be coil packs or ignition module or MAF

Hmm apparantly there's several different ones. the J one is used in the Audi TT 225HP, whereas the VW ones regulate turbo pressure differently.

I'll price up an ignition module too.