WR quattro won't start

[Colesy]

Sorry to any S2 purists but I this forum is a lot more active than any others I've found so thought it would be worth posting on here.

The WR won't start, it cranks and sparks on a few cylinders momentarily every so often but won't fire on all 5.

Does anyone have a link to good guide to follow and work out what's wrong. The coil is fine, the plugs are all sparking, it stinks of fuel but I haven't done any proper testing of fueling. Nothing has been changed, one day it ran faultlessly the next it didn't.

Thanks in advance for any pointers.

[mac2226]

When I had a wr quattro the first thing that went wrong was a starting problem it was the fuel pump relay in fuse box I had to check it on side of road for fuel and spark once I had figured out what was wrong with it. Could be wrong but worth a try all best Michael

[adam g]

If you Google audifans Isham research you will find a link to phil paynes old site with loads of fault finding info.

I would recommend checking for a split/loose hose on the air intake system.

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[Monkeymagic]

Are you sure you are getting a healthy spark on all 5 and not a maverick spark? As above really work your way through Phil Paynes step by step guide on testing engine sensors. I'm going through the same pain at the moment, although I suspect it was due to a faulty WUR and fuel distributor.

[Ian Simmonds]

Are you sure you are getting a healthy spark on all 5 and not a maverick spark? As above really work your way through Phil Paynes step by step guide on testing engine sensors. I'm going through the same pain at the moment, although I suspect it was due to a faulty WUR and fuel distributor.

Yes, this, look for a wasted or maverick spark, basically the WR needs a timing position before it sparks properly, so crank position sensing is critical. If this signal is missing, the spark plugs do arc but are very, very weak and it won't fire.

Crack a fuel line at the metering head and crank to prove flow, look for wet plugs after cranking or pull an injector to prove metering head fueling... (literally 'just' as in Friday, got the Ur back post metering head failure).

Beyond that, blown boost hoses tend not to prevent starting unless they are completely missing. Follow the late PP's guide though, it should cover all basis...

[quattro-nick]

you can do a small fast diagnosis by removing the turbo hose on the intake,let someone start the car and spray some brake cleaner in the intake,if the engine begins to run, you know that the problem is in the fuel system,if it's still do nothing, than is it a ignition problem

[newsh]

Maverick spark
Check the Hall sender in the dizzy.

[Colesy]

Thanks for the pointers everyone.

Have checked the fuel pump relay and it's working properly.
Have also checked all 5 plugs and they appear to have a strong spark. The plugs do look wet though.
Compression is ~ 90 psi for all 5 cylinders.
Fuel flow to the Metering head is strong well over 900ml in 30 seconds.
But the fuel flow to the injectors seems weak, a dribble rather than a spurt. So thinking this is pointing to the metering head or something that controls it so the Control Pressure Regulator or the air metering dome?

I've now found all the diagnostic tests on a mirror of Isham Research so will check the Hall Sender too.

[chezz]

Did you bridge the fuel relay in order to test fuel flow from the injectors? Do you know what the history of the cam belt changes?

[Colesy]

Did you bridge the fuel relay in order to test fuel flow from the injectors?

Yes, and tried starting it with the relay bridged and no change

Do you know what the history of the cam belt changes?

No, it's top of the to do list, a new cambelt etc is on a shelf, the current belt looks in good shape though.

[adam g]

Have you looked at the pressure regulator on the side if the block for any sign of leaks. I had 2 go kaput resulting in a small fuel leak from under the plastic cap on the front. Car wouldn't start until replaced.

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[chezz]

https://youtu.be/XabbJ3HaeuI. If you 'bridged' the fuel pump relay and placed the injectors into measuring containers- then, the fuel should be flowing, with a very 'healthy pressure' - 'visibly' and 'audibly' there should be a 'high pitched' note On a vehicle of this age, it will have probably have had several belt changes and invariably they do not always receive a crank pulley replacement... Combine this with a poorly torqued up harmonic damper and you can often end up with broken keyway...

[Colesy]

Thanks for the suggestions, just thought I'd post an update.

I've not had any time at all to do any fault finding...

But today having not touched the car for two weeks, I just thought on the off chance I'd see if it would start... First attempt and it fired straight up!

So I'm not sure exactly what have might caused the non start, my only thought is that maybe something had got wet and has now dried out.

Any ideas?

[SA BOY]

Leaky injectors causing the cylinders to flood and not to start. Fuel will evaporate over time and hence engine will fire up again. Check for dripping/leaky injectors.

[LSG]

Leaky injectors causing the cylinders to flood and not to start. Fuel will evaporate over time and hence engine will fire up again. Check for dripping/leaky injectors.

Yes but it can't be fuel in the cylinders coz he compression tested it . So any fuel would have eventide then. I would have thought electrical problem. I can test and clean injectors for you if you think they need doing. Your have to pay postage .