Slight rough idle & warm starting... VR6

[dr_mat]

In my experience, any multi point fuel injected car that can't fire up cleanly inside a couple of cranks has a problem, so you do need to get to the bottom of the warm start issue. The rest, I would say, sounds pretty normal though..

Regarding rough idle.. most of these cars are lightly used. I would guarantee that if you do 20 miles a day at steady motorway speeds that rough idle will disappear in a week... and come back again after a few days of short journeys.. just how it is on old engines. You'd be looking at valve stem seal repairs and the like to resolve this permanently I would think.

Regarding cold start revs. I would say this varies with the extremes of winter temperatures. It's been pretty cold of late... bear that in mind in what you consider is normal.


A Corrado is for life, not just for the MOT.

[fendervg]

2.8 VR6 engines found on the Golf 3 and others use a 3.5 bar regulator, the 2.9 VR6 ABV needs a 4 bar.

I wouldn't believe any of the other stuff in the description - makes no sense. All the FPR does is maintain a constant pressure in the fuel rail, everything else is done by the ECU and the injectors.

RE; the FPR - is this the sort of thing to buy - why is considered an upgrade - isn't the 4bar is standard fitment on the 2.9? http://vi.vipr.ebaydesc.com/ws/eBayI...rsion=890d5c63

[pfnsht]

I see your point mat! I do use mine quite a lot at the moment, for an old girl - 100 to 200 miles at the weekend (fast roads) and around 50 miles in the week.

The warm start is pretty constant - today started up from cold on 2 or 3 starter turns. 8 miles to Sainsbury's along B roads and restart was about 10 turns. Off to nursery (less than a mile) and around 15m mins fannying about picking the kids up and again 10 cranks to start.

And thanks fendervg - that clears that up for me.

[pfnsht]

Update - whilst I await my diagnostic reader to arrive I decided to in plug the air flow sensor and the car started straight away when warm. Plugged it back in and same symptoms - difficult to start. Might have struck lucky.

Next question my part number is 021 906 462 - but a Bosch replacement sensor is the best part of 200 quid. Last time I replaced one of these I paid about 60 so has anybody else managed to find one for a more reasonable price? I’m assuming Bosch is the right make to go for and is what is currently on the car.

Cheers,
Matt

[dr_mat]

Update - whilst I await my diagnostic reader to arrive I decided to in plug the air flow sensor and the car started straight away when warm. Plugged it back in and same symptoms - difficult to start. Might have struck lucky.

Bear in mind that if you unplug the MAF the car goes into "default" fuelling mode and the car will run differently .. the MAF may not be the fault. Get a used one to compare...


A Corrado is for life, not just for the MOT.

[pfnsht]

ahhh didn't realise but should have figured everything is all connected somehow. Would I be right in thinking my fuelling - i.e. pump and pressure in the system is good if default fuelling starts the engine with 1 or 2 cranks (vs 10+ when it is connected)?

I have a multimeter but haven't had to learn how to use it. Now seems to be a good time to start testing sensors? Also what's the Blue sensor under the MAF? I noted the black, blue, yellow from the termostat and was thinking the one under the MAF was an air temperature sensor?