Low down / light throttle hesitation

[Tjninny 10]

Hi,

Any pointers as to how to sort the following:

Vr6, not driving and on a light throttle opening the engine bogs down and almost stalls, but as soon as I put my foot down more it will rev quite happily to the red line. It almost feels like it clears its throat and smooths out the more throttle I give it - could this be a coil problem, as I can see a small crack in the coil body, but on the side near a bolt, rather than where the leads connect. I have already fitted plugs and new leads.

Cheers,

Tim.

[vw rule 19]

Hello Tim,

 

does it seem hesitent when engine is cold or when warm,

or does it do it all the time on slight throttle ?

 

A lot of VR6 owners on here have had similar issues with their cars,

and yes it has been the coil as they've had cracks in the outer casing / insulation.

 

Plus they've had problems with slight throttle when fuel is really low in tank i.e fuel pump playing up.

 

 

Hope this helps.

 

Si

[Tjninny 10]

Si,

Thanks for the reply - it stutters when warm, although I've not yet had it on the road due to doing a lot of work to it. When I put my foot down a little it seems to nearly stall, but more throttle and it revs through the stutter. Also from idle to full throttle, ie no part throttle, it "rumbles" as if it is missing, but clears the more it revs. The coil body is cracked, but as I mentioned it is next to one of the bolts that fasten it to the engine, so it could be that, and also it is low on fuel - better get some in and see from there. I know a new coil from AVS is £123, not bothered if that's what's needed, but obviously not 100% certain yet.

Thanks,

Tim.

[emmib 10]

hi tim

i have a vr6 storm with exactly the same issue as you have got, my mechanic had her for a week, he has replaced the coil pack and fuel filter, and when getting her back:scratch:, she drove fine for a day, then the same issue returned, leaving me slighlty sad to say the least :-((

and miffed as what it could be, thanks to si for the idea of fuel pump, will tell mechanic that one, but like you would like some help and advice, if anyone thinks it could be anything different i would be very grateful

i hope we both get them sorted soon, i really miss driving her

thanks

emma:scratch:

[vw rule 19]

These components below can have similar symptoms:

 

 

Throttle body clogged up with sludge and muck.

This can affect the butterfly's operation or vacuum hose ports can be blocked up in the valve body.

Or butterfly flap shaft warn with in valve body.

 

Throttle position sensor warn or playing up.

Some of these sensors track the full movement of the throttle,

where as others I think only check for throttle off and full throttle.

 

Lambda sensor (O2 Sensor) warn out.

The ECU will dump in extra fuel due to not being able to measure for fuel deposits with in exhaust fumes.

Symptom is slight misfire or engine seems under powered.

Normally have engine warning light come on with most cars when these go or play up.

 

Crank sensor

Kev Bacon one of the members on here has mentioned the crank sensor before,

I think on his VR6 it played up or something.

 

The crank sensor has to be able to sense movement going past it's face,

so on the crank pulley there is a steel toothed ring which the crank sensor pulsates off,

but there is a magnetic charge build up with in the sensor so it's able to sense when the teeth are passing it.

This can result in small metal filings being attached to the crank sensor's face which can affect it's operation.

I think Kev had that kind of issue with his ?

 

Fuel tank lift pump as already mentioned in thread.

 

 

Have you got a ECU diagnostic scanner to read for any fault codes with in system.

 

 

Hope this helps.

 

Si :thumbleft:

[emmib 10]

good morning si

many thanks for your advice,its much appreciated and i will tell my mech today the parts you have mentioned, shes been on diagnostics a week ago but apart from the cam sensor, no other faults came to light!! there are also no warning lights apparent when driving her, (which at the moment i am not doing as unsure wether i will cause more serious damage if i do) so sad to see her sat there waiting to be collected once more by my mech, although not all bad as have the privilege of driving my boyfriends rado, :smug: hopefully her issue/s will be sorted soon:cheers:

thanks

em

 

---------- Post added at 6:58 AM ---------- Previous post was at 6:57 AM ----------

 

good morning si

many thanks for your advice,its much appreciated and i will tell my mech today the parts you have mentioned, shes been on diagnostics a week ago but apart from the cam sensor, no other faults came to light!! there are also no warning lights apparent when driving her, (which at the moment i am not doing as unsure wether i will cause more serious damage if i do) so sad to see her sat there waiting to be collected once more by my mech, although not all bad as have the privilege of driving my boyfriends rado, :smug: hopefully her issue/s will be sorted soon:cheers:

thanks

em

[vw rule 19]

Hi Emma, you could always keep your boyfriends car, quick quick drive it away now, he's coming :lol:

I think this is where I get :splat: :lol:

 

No worries mate, hope your Mechanic finds the fault and your VR6 is back on the road full time :thumbleft:

 

 

Si

[Stonejag 10]

Nobody's mentioned the MAF yet, which is the other major cause of weird throttle response. Unplug it and see - the difference it makes to the running should be obvious, if not then replace. That or a vacuum leak would be my bet, try removing the throttle body elbow and see if it's cracked around the corrugated parts (if plastic).

 

As above mine did this just before the crank sensor failed but it was more of a hunting revs thing than stalling.

 

Stone

[emmib 10]

:cheers: yay she is back on the road and all is well, it was the cam sensor causing all the problems, so new one put in and she is running like a dream, fab drive to work this morning!!!:dance:

thanks to stone and si for all their help and advice

em

[iow_corrado_g60 0]

I have to agree with Stone Jag, best to always check the MAF first I've just put the Golf back on the road yesterday, took her for a good drive today and there is slight hesitation between 1000-1500rpm the MAF will be my first port of call. when I get home from work tonight,

 

EmmiB out of interest how much was your cam sensor?

[Stonejag 10]

Should have asked, I have a spare cam sensor in the bits box ;)

 

I had MAF trouble the other day after replacing it with a different one (swapped to an aluminium MAF housing with a bung welded on for a 1.8t inlet air temp sensor, and used my spare instead of swapping my working one into the new housing). It was pretty pronounced and luckily I've had it before so recognised it immediately :) The VRs don't seem to rely on the MAF when you are accelerating so that feels fine, but if you let off the pedal and allow the engine to slow down slightly on its own, then the next time you hit the pedal it bogs down instead of pulling straight away. It took me longer to find my Torx bits than to do the swap back to my working sensor :lol:

 

I've also had the connector come loose before as the little wire retainer piece had pinged off and it vibrated free. Same symptoms but you only need a piece of tape to fix it!

 

Stone