Flat spot.

[VR6Andy 0]

Now then folks, advice needed. On my 96 Vr I have had an intermitant flat spot for about 6 months. The fault rears its ugly head about once every 2 weeks.

It occurs between 500 and 1500 RPM but usually at 1000 RPM.

The motor seems to be short on fuel and when i put my foot down it takes a second and picks up, this happens most at junctions and rolling starts.

Had recent leads and plugs and I have been advised that its probably the coil packs and there is 2 of these.

Does this sound about right as a solution to my prob or am i way off the mark.

PS can someone confirm is there 2 coil packs and any ideas on price. ~

[binliner 0]

Im no expert so I may be way off but it could be the throttle body needs cleaning... I had a similar problem on my gti

[maak 0]

vr6Andy, FWIW I have a similar problem to you, if I ever get to the bottom of it, I'll be sure to let you know. Binliner, is cleaning the throttle body an easy thing to do ?

[binliner 0]

not sure... I didnt know what was wrong so I took it to a garage and thats what they did. Im sure its not too tricky and hopefully someone wil post and tell us the best way!

[speedo 0]

Try cleaning out your throttle housing, carb cleaner is good, then reset throttle settings.

If you dont have the equipment (who does!!), then leave your ignition on when below 60`c (in the morning is good) for 3 minutes, and that will reset it.

Is your chain noisey?? if so then your cam timing may be out, as there may be slack.

But personaly, i would replace the cam position sensor. It sounds like it is not telling the ecu the exact position of the cam`s.

Have you had the head off??

Reason i ask is that when i put my flowed head on, I somehow damaged the exhaust cam,(you have to hold it with a spanner half way down while undoing the pulley end bolt, and it was fu*"'#ng tight, and didn`t undo, but we recon somehow twisted) and it gave a simular problem to yours. It was realy flat every now and then.

They got replaced with some shricks, and a new sensor, and its REALLY REALLY nice now!!!!

When exactly did your fault start??

Have you had the fault memory checked??

[VR6Andy 0]

The problem has been on and off for around 6/9 months. I haven't had the head off and taking a guess on the previous owners i would say that it has never been off, or had any major work done.

I can try the cleaning of the throttle body and resetting trick.

The chain does'nt sound noisy but the Vr has 80K on the clock, having said that, it's had all the services at the right time etc.

I take it your not thinking it could be an electrical fault?

[VR6Andy 0]

I've not had the fault memory checked but can do, will it tell me if there is a prob with the cam position sensor.

[andysteele 0]

maybe just a shot in the dark but I used to get my VR service at a mates garage, he had one before me and had similar problems and said he changed the fuel filter, so whenever he did my servicing he always changed it.

I moved away and have now started to do the servicing myself, I went to VW to get the parts for a service and they were shocked i had even asked for a fuel filter for a VR and didnt think they would have any. They say it aint a service part.

Mine hasnt had one for 20k now and its starting to have similar problems so i`m going to change it and see if it helps.

[zerocool 0]

disconect the battery for 5 mins,then reconnect and turn the ignition on for 1 minute,but do not start the engine.

after the ignition has been on for 1 minute start the enigne and let it idle for approx 30 secs,then take for a drive.

this process resets the ecu values and allows the ecu to relearn its settings to the engine sensors.

my vr had a flat spot,and after doing the above it is fine now.

[maak 0]

Thanks for this zerocool, just looked into this further and some chap has said this:

"With the engine fully warmed up on the oil temp., do a basic set-up (tuning)

by disconnecting the battery for a few seconds to reset the ECU (use the

earth side to disconnect). The trip meter should have reset after this.

Reconnect and then within 10 minutes of re-starting the engine complete the

three following things.

a. Idle for 1 minute (at about 5mins in the run)

b. Accelerate in 4th starting at 30mph with the throttle held at halfway

(foot steady) for 4 seconds minimum, not top limit but 10 seconds is good

enough for a sample

c. Put into 3rd at 4,500 rpm (can be as low as 4,000) and floor it for 3

seconds (Do this on a rising hill to stop you overspeeding and getting a

ticket plus BE CAREFULL! The rev limiter will take care of the engine, you

watch the road for clowns!).). You'll hit 80 plus easy with this so pick a

stretch where you clear viz and a decent climb of say 1:10. Speed isn't the

important thing, fully open throttle setting is.

This must be done in the first ten minutes since TURNING THE IGNITION ON,

not from re-connection. During the set up, each point, close throttle, half

open throttle and full throttle can be done more than once and 10 minutes is

more than adequate time.

The ECU will now have the optimum settings."

Worth a go?

[VR6Andy 0]

Have spoken to VW mate re this debate, I am taking the Vr into the garage when he will :-

1) Clean the throttle body

2) Place the VAG COM on it and check for faults

3) He has told me that there is a computer or thingy me bob that when placed on the COM plug in points can reset the ECU to factory settings. When i told him about the disconnection of the battery he informed me this sets the ECU to emergency settings and this was best avoided!!!!!!

4) Full service including fuel filter etc

I'll see if this ugly flat spot rears back up after the visit to the garage. Hope not.

[maak 0]

Oo, OK, I think I'll give the battery thing a miss then. Wish I had a mate that was a VW technician!

Hope you get it sorted VR6Andy, keep us informed.

[zerocool 0]

strange I have never heard of any vehicle going into emergency mode through disconnecting the battery,vince at stealth racing showed me that trick,and he does know his stuff