VR6 starting but then cutting out - not every time though

[Mouser 10]

Hi there, my son recently bought a Corrado VR6 1996 reg with almost 70k on the clock. Being completely honest with you he's a bit out of his depth as everyone in the household is useless with cars, and looking online in google all the help sections I see explain it jargon and acronyms we can't make head nor tail of, a chap in work said the guys here are very helpful so I thought I drop by.

 

The Corrado starts up, and then cuts out unless revs are kept really high. The car will stay running if you set off in gear and keep the revs high for a short time. It doesn't happen everytime it starts though which is what's confusing us, it's done it in cold and warm starts so I haven't a clue what to check.

 

Last night it got worse and starting cutting out, he pulled off in gear, got a short distance and it died again, when he tried to start it up it wasn't even firing your could hear it trying to start, it was only after pumping the gas as we turned the ignition it finally started up again.

 

Any idea what could be causing this? If you could helpme in idiots terms that would be helpful, or even just some suggestions I could pass on to the mechanic in the garage.

 

Thanks very, very much in advance.

 

Also one last thing, is the radiator fan meant to stay on for a few minutes after the cars been turned off?

[Mouser 10]

Other notes- it was sat for a long time, and the fuel pump was cleared of crap, had new leads, spark plugs too.

[Portent 0]

Yes the radiator fan can stay on for a short while although several minutes does dsound a little in the long side.

 

The stalling issue sounds like a sensor of sone kind but the first thing to get done would be to get the VAGCOM codes read as it may show up an error code. You could pay a garage to do this or perhaps buy a cheap reader from ebay.

 

I'm sure someone else will be along shortly with more knowledge than me, so coming to the forum is certainly a good thing :)

 

Edit: Idle stability valve, coolant sensor or crank position sensor?

Edited April 11, 2014 by Portent

[seanl82 23]

There are tons of things it could be unfortunately. Being sat for so long doesn't help either as seals and actuators become gummed up and/or brittle. First things you can do are all free/cheap and easy stuff. Take off the idle stabilisation valve and leave it to soak in carb cleaner overnight. It's located just behind the engine on the right hand side as you look into the bay, and is a cylinder about 4inches in length. Clean up all electrical contacts and earth points by disconnecting them, giving the all a little wire brush or a bit of emery cloth to the points, electrical contact cleaner to all electrical plugs, re-secure and grease up earth points. Check all the thin black vacuum hoses at the back for splits or poor connections, and the intake air pipe (big black one coming from the air filter) again for splits/cracks including underneath and especially in the inner part of bends. Don't think it'll be crank sensor as it doesn't usually start if it's defective. If you go from there it narrows down the possibilities a little, then let us know how you get on and we can advise from there.

Where are you located? Someone with vagcom (diagnostics equipment) may be local and offer to help you out which will save you a fair amount in garage fault finding bills.

Welcome along by the way, and hope it doesn't take too long before she purring along as intended! :thumbright:

Edited April 11, 2014 by seanl82

[n3p 3]

How old is the fuel?

[seanl82 23]

How old is the fuel?

 

 

Good shout!

[CazzaVR 0]

As Sean says, it could be anything. I'd start with the intake pipe work and ISV. Only way to be sure is take it all off and closely inspect for splits, holes and blockages. I've had similar probs in the past with the same symptoms. One was a failed ISV, another was the big intake pipe between the air box and throttle body was split underneath and another time, the sponge from inside the ISV damper box (little black plastic box behind the ISV) had got sucked into one of the pipes. The last one was the most difficult to sort- 2 garages spent an age and couldn't work it out. Finally sorted it myself after taking all the pipes off. It really is an easy job- just a few jubilee clips. To get to the ISV you will need to undo the spark plug leads and remove the rear black engine cover, which has two bolts. All really simple.

 

Remember to use the search on here, as this has all been covered before. Sometimes you'll get better results by using google instead though ;)

[Mouser 10]

Ok thanks lads. I'll have a tinker tomorrow, it's booked in to the stage for Tuesday aswell so I'll pass on this info to the mech to plant some ideas for him. I'll keep you all posted, thanks for taking the time to reply, we can help with PC's in this house but not cars haha!

[Mouser 10]

The fuel that originally was in would've been old but my sons been running high octane through it for a month now.

[Stonejag 10]

My money'd be on an intermittent vacuum leak - especially if it has the hard plastic type of intake elbow (back-left in the bay, between air box and throttle body) as they're notoriously bad for cracking in the corrugations - the rubber style is better. Also run your fingers under the vent pipe attached to the back-left corner of the valve cover on top of the engine (should connect to the air inlet via a small blue plastic joining piece with a 2-pin electrical connector on it) - if your hand comes away oily then this has split underneath and will contribute to poor running. Replacing it with standard rubber hose is a quick fix if so!

 

Stone

[MikeVR6 0]

Disconnect the Mass Airflow sensor and see if it runs the same. If so, the MAF is not working. You can remove the sensor and clean it carefully with electrical cleaner spray. Mine was doing something similar.

Failing that, the Idle Stabilisation Valve might be clogged up. This is fairly easy to remove. At the back of the engine beside the throttle. 2 torx hold the rear engine cover on, undo the electrical connector and pipework going into it and give it a wiggle out of it's holder. Seep it in carb or brake cleaner for 10 minutes, Shake it out along with the sootie deposits. Give the valve a wiggle back and forth with a screwdriver to check it works and refit. This is a good general maintenance tip also. Once a year or so.