Naughty 'Valver - Relay 30? Update5 - VAG-COM Results

[stow1985]

Have you changed the dizzy cap? or checked it at least, might be damp?

I've got a similar problems with mine, which still haven't sorted 

If all goes well I might get a new VW coil, leads, dizzy, rotary arm, earth strap, exhaust manifold gasket and take the inlet manifold off and give it a damn good clean as its mining inside...

[Jasikasisback]

Inspect injection flange mount. Could be leaking and causing problems! I currently have the same problems of rough idling in drive but ok in neutral a hesitation engaging into first fear on an auto box. Car works normally once in gear. Pain in the neck trying to find the culprit. I feel your pain.

[Stirring Moose]

Ok, finally got into a bit of Golf twiddling tonight - last night was lost to the plight of a newly supercharged Jag that seems to suck harder than it blows and as for Wednesday just don't ask  ... but I digress! Have made a brief start on the list of wisdom you guys have kindly posted up here. Before starting I fired the car up briefly and she idled ok, I think just as a result of drying out a bit. Throttle response was still bad though.

First check was alternator charging voltage. Showed 14.5v which is a touch higher than I expected but it stayed rock steady up and down through the rev range so doubting that as a cause. Then did a load of connection checking, unpluging, cleaning and replugging the following: TPS, Idle Switch, Injector Loom, Crank Speed Sensor, Inlet Air Temp Sensor, Dizzy Hall Effect Sensor. Result is no change - fairish idle but stumbles if you jab the throttle.

Next step is to whip the battery and battery tray out and check the earths underneath. Just out of interest, what actually earths down there? Can find reference to them in the Hayne's book but only as numbers, not any description of what they do.

S.M.

[l333]

hi
as mentioned before make sure you realy check the wiring that runs behind the inlet manifold well as the casing on the wiring breaks off and the wires short out on each other inside the trunking. mine done this and nuked my ecu when i rebuilt the engine last year lucky i had a spare.

[Stirring Moose]

Did as planned and went after the earth that lives under the battery tray. Looked pretty horrific on first sight but actually wasn't so bad when I got it apart. Cleaned all the connecters and reassembled them onto the earth stud with much copper grease. Put everything back together (complete with repainted battery tray - cheers Father!) and fired her up. She still stumbled initially but then cleared out and now, with a bit of running, is working well again. Can't really claim a total victory yet as it has only been one day but it's the best we've had so far!

S.M.

[Stirring Moose]

And it came to pass that, after nearly a week and a half of working perfectly, ye old problem did return. And Mr. Moose looked upon his 'Valver and was sore distressed!

Basically, the car has not been used for two or three days and now has started hesitating again. Only at irritation level rather than full on undrivability like it was but still not right. Seems like problems start whenever car is left for a while. My next plan is a good furtle in the dizzy cap - have got a replacement cap in stock so can try that. In the mean time, I have seen a number of mentions of the temperature sensor sending things a bit mental, but that if this fails it shows up on VAGCOM. So far mine always seems to scan ok. Is there any way this can go wrong without putting anything in the memory?

S.M.

[twotwofour]

Watching with interest as mine has similar problems when it feels like it

[Leon27]

When the fault occurs see what the sensor is reading using measuring blocks on vag com. If you feel its implausible and does not match what is on the cluster its most probably faulty. The car wont see it as a fault if its still reading a signal but if the signal reading is -45 degrees or 180 degrees then that will have an effect. I've seen this on my old Mk3 where the reading wasn't moving, but disconnecting the sensor logged a fault.

Vag-Com is pretty useful when you are using the measuring blocks as you can see what the sensors are doing
      
Group    Column 1   Column 2            Column 3           Column 4
                
001   Idle Speed   Coolant Temp   O² Sensor   Adjust. For Basic
002   Idle Speed   Engine Load           Injection Timing   Air Mass Injection
003   Idle Speed   Air Mass Injection   Throttle Angle   Ignition Angle
004   Idle Speed   ECM Voltage   Coolant Temp   Intake Air Temp
005   Idle Speed   Engine Load     Vehicle Speed   Operating Condition
006   Idle Speed   Engine Load           Intake Air Temp   High Correction Factor
010   Idle Speed   Engine Load           Throttle Angle   Ignition Angle
014   Idle Speed   Engine Load   # of misfires   Misfire Recognition
020   timing retard 1   timing retard 2   timing retard 3   timing retard 4

Interesting about how leaving the car for a while affects it, if that is the case then a new dizzy cap with a new arm could help and it will improve the spark so it is always beneficial. Someone earlier mentioned whether you replaced your dizzy, have you done your leads etc as well?

[Stirring Moose]

More very interesting info there, thanks for that. Unfortunately I don't have my own VAGCOM gear as yet so can't check this out straight away but will certainly see if I can sort something sometime. Other slight issue I have at the moment is that, having seen a bit of use in the last couple of days and thus got some heat through her, the car is back on song, really working well. Unfortunately I kind of know now that as soon as I leave her for a bit, she'll play up so still need to find a fix. Going to press ahead with dizzy work when I can. It's a pretty obvious one to tick off the list and I should've got on it sooner, both on the basis of what people have suggested and off my own bat, but I foolishly thought I'd nailed the problem with the earth cleaning. Silly boy!  :embarassed:

S.M.

[Edwh0re]

I had a similar sounding problem with my 8v when I first got it.  It would hesitate at 3000rpm at the beginning (just noticably) but after a couple of months it was absolutely gutless above that figure and ran like a bag of turd.

After changing everything in the electrical circuit such as coil/leads/dizzy cap and rotor arm/plugs, fuel and ecu relays, the lambda sensor (twice) and the thermostat....it turned out to be the air flow meter.