Another Valver wont start.

[Dave W 0]

I have a 91 1.8 16v that has been stood for 8 years. I have replaced external pump filter and accumulator. I now have fuel up to metering head but she wont start. Does any one know if there are any parts that seize up in metering head after time. I have fuel pressure at injector outlets on metering head,can injectors seize or block. I have good spark from dizzy.Plugs are dry, so no fuel. How do you remove injectors, don't want to break owt. Any tech help very appreciated. Cheers , David.

[aide 0]

8 years is a long time to be stood, my valvers didn't like standing for 2+wks.

 

injectors are hydraulic activated at very high pressure, they're fully mechanical also so high tolerance machining means needle valve could be seized. there's a plunger in the metering head which could stick also. injectors just pull out (with force) best to do when warm which gives you an issue...

 

there's a heap of pneumatic, hydraulic and electromagnetic sensors all over the KR engine that can give rise to starting problems - to the point of web based diagnosis being very difficult i'm afraid.

 

get yourself a mechanical fuel pressure guage and a book called 'how to tune and modify bosch fuel injection' or similarly titled book, only way i learnt :)

[Dave W 0]

Cheers mate, have another go at it today. Could be a long road. Have you ever taken a metering head to bits.

[aide 0]

yep i've had a metering head apart, its very simple but high machine tolerance stuff, they normally don't go too far wrong its all the associated sensor gubbins that causes issues mostly, or unknowing adjustments to idle and mixture screws.

 

simplistically a plunger with a rebate moves between two plenums - one supply, one distrbution and depending upon the height of the plunger and the degree to which the rebate sits between the two plenums determines the fuel flow to the injectors. the plunger is controlled by the air flow plate which sits in the intake tract after the filter.

[Jim 2]

People do seem to make a bee line for the metering head, but I wouldn't be touching it unless it was a last resort.

 

Removing the injectors is as simply as just pulling them out - but given how long the car has been standing, and the age of the car generally, you may want to look into replacement seals for them. Some info on removal and parts to replace here:

 

http://the-corrado.net/showthread.php?t=14341

 

Cheers.

[Dave W 0]

I pulled out number 1 injector, stuck it in a jar and turned her over. Nothing at all. Split injector from pipe, still nothing. Opened no 1 on top of meter head and turned over, nowt. Got fuel pressure going in to meter head so think something has seized inside. The big metal plate above air filter only moves couple of mm. Getting closer to problem. Next job to remove meter head and check whats what. Have printed off the bosch book , so will have a read up first.

[aide 0]

when you say you have changed the 'external pump filter' do you mean the filter and/ or the pump, can you hear the pump whining, can you feel the lift pump whining in the tank?

 

the air flap should move freely, defo more than few mm. bear in mind the metering head has a control pressure supply to the plunger, that's why there's three supply pipes to the metering head, this pressure is controlled by an bimetallic temp sensor on the block (called the warm up reg (WUR) i.e. leans of mixture) if that pressure is too high it can prevent the air flap rising.

[vw rule 19]

Could be the fuel distributor like you say sticking slightly.

 

The fuel distributor is what all four fuel pipes bolt in to on top of the air box / metering head.

 

It might also have a regulator on the engine block like some of the early Audi's had,

some of the KR blocks had them as well, but only on the early KR block I think.

 

I take it you have got power to the fuel distributor and fuel governor and air flow sensor,

which are on the metering head all three of them, as Aide has already said.

 

Hope you get her going very soon.

 

Si

[Dave W 0]

She lives !!!!!. Took meter head to bits. Central plunger thing was stuck. cleaned it all and put back together, and she fired up. What a result. Well chuffed. Bit smoky and stinky on the old petrol but that will sort itself out with new juice. Cheers for all the help and info. Over the moon. Knew she was a good one.

[aide 0]

result!