95 VR6 hard to start - sometimes

[Mawrick 0]

Just picked up my first Corrado, it's a 95 VR6, got about 119000Km on the odometer, and complete service record etc.

 

BUT it have a few small problems, one being that it's sometimes hard to start. It seem that it's only hard to start when it's a bit warm, either from driving it, or when the weather is good and it get warmed up that way.

 

It seem that it's easier to start when it's cold, then it will "fire up", and then almost die out again, but seems likes something is "kicking in" just before it dies again, and then it's ok.

 

When it's warm I have to crank it, and it might fire up, then die, then have to crank it again, and when it eventually fires up I have to "pump the gas-pedal" a few times or it will die again. Also seem like it revs up a bit before dying. (Atleast my Passat VR6 (although a bit older) doesn't seem to do the same when it comes to "reving up".

 

Any tips on where I should start?

 

PS! It does not throw any error codes when scanning it with VAG-COM.

 

thnx

[VR6 0]

The search will help.

 

search.php?keywords=%2Bvr6+%2Bstart*+%2Bwarm&terms=all&author=&fid%5B%5D=1&sc=1&sf=all&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

[Mawrick 0]

ok, thnx, I'l check it out!...:)

[Mawrick 0]

Would the fuel pressure regulator show up in VAG-COM ?

 

(I see in another post that it might be the source for such problems).

[CrazyDave 0]

Would the fuel pressure regulator show up in VAG-COM ?

 

(I see in another post that it might be the source for such problems).

 

Nope....

 

Whats the coolant temp in vag-com? If it's showing a constant number (75 deg IIRC), the blue sensors died or the wire to it.

 

Does the ISV buzz? Could be dirty or faulty.

 

Check the multi plug to the engine for corroded pins (right hand side by the engine water bottle).

 

VR6.jpg[/attachment:3edv92y8]

 

Click to see the text. Hope this helps?

[Mawrick 0]

ok, thnx I'l have a look into this, corrosion might be present as it only drove about 300 km the last 4 years or so.......before I picked it up, it ran fine for the 1000+ km I had to drive it back home though.......lol, but where always this warm-start problem along the way....;)

[Mawrick 0]

I hear a buzzing sound around that area, how does one clean that thing, if it's not faulty? (Also does early 1992 VR6 engine use the same ISV?, as I have another engine laying around, might have that ISV thingy there...).....if not nick it from my Passat...:)

 

Also how do you disconnect that wiring harness?

[CrazyDave 0]

Should be a few guides to cleaning ISV's on here, usually involve taking it off and soaking it in brake cleaner. Don't poke things into it as this might damage the internals.

 

Does the engine idle OK when it does start? If it does then the ISV is fine. ISV's are the same on all VR's AFAIK.

 

The harness connector twists anti-clockwise or top towards the front of the car to undo. It may be tight but you should be OK by hand (don't use grips on it).

[Mawrick 0]

Ok, thnx, yea it idle ok once it's started successfully (although it can "start", then die, seem like something isn't able to "kick" in before it dies).

 

The former owner told me that it will fire up and start if you push it to start and also if you put start gass into it.

 

Also while I crank the engine I can smell petrol, so I guess it might "flow" the engine to much?. (Will it do that with a faulty FPR?)

[dr_mat 0]

You want to scan the ECU for error codes, and spend a happy half hour checking the measuring block readings to make sure all your temperature sensors are working right.

Warm start problems are typical temp sensor issues - the engine runs cold start enrichment when it's warm .. and that's bad ..

It'll kill your fuel economy aswell as destroying the catalyst with all that excess fuel.

[Mawrick 0]

I have scanned it, it doesn't throw any errors besides one ABS sensor :)

 

For the 1000+ km I drove from where I picked it up the fuel consumption where normal, much the same as my other VR6.

 

btw, what do you mean with the "measuring block", and how is that checked?.

 

thnx

[dr_mat 0]

VAG-COM software (aka engine diags) can read live sensor values out of the ECU.

 

http://www.ross-tech.com/

 

It will only "fail" a temperature sensor if it's electrically dead (i.e. shorted out or open circuit).

[Mawrick 0]

Ok, never did live readings with my vag-com, I'l look into it (As for some reason the other VR6 I have (passat) doesn't allow live readings, doesn't seem to be able to connect to the car while running), I know the Corrado does though...:)

 

thnx again for the tips

[Mawrick 0]

btw, how do you remove the cover over the temp sensor etc, without damaging it?

[Mawrick 0]

Seem to be some corrosion on 4-5 pins on the female connectors, any tips on how it could be fixed?

 

I have sprayed some elect cleaner (CRC) into it......

 

 

Are these pins changable?

 

EDIT: Or could some of the connectors been made out of copper? (it's 4 connectors)

[CrazyDave 0]

The cover slides to the right, it's just clipped on.

 

I use Servisol from Maplin Electronics, it's a proper contact cleaner and lubricant. Even use it on the volume control on my old NAD stereo when that goes crackly :)