camsensor faulty NOT!!! New engine needed maybe????

[J.C 10]

Hi

I've been having a misfire on my VR6 since I got it a few months ago,

I think I've found the problem, one of the first things I did was to swap the coilpack, then the camsensor with my golf VR6 which was running sweet, neither made any difference so I left them in their new vehicles.

today I was playing with it (as usual!!!!) and unpluged the camsensor and there was no change, checked supply voltage to sensor(OK), checked continuity from sensor to ECU(OK)

checked for output whilst engine running, was outputting supply voltage (constantly)

can't wait to get a new sensor tomorrow and see what this baby will do(Schimmel 263 fitted but not remapped(yet))

steve

P.s should I phone up the Golfs new owner to tell him the camsensor on his new car is probably faulty??

Edited May 31, 2013 by J.C

[Supercharged 2]

Have you had it on VAGCOM to confirm??

 

Was a new sender ring fitted with the cams?? old ones crack when the pulleys are torque'd up and cause cam sensor symptoms.

[J.C 10]

I had it put on my mates snapon diagnostic thingy, a couple of weeks ago

came up with

00525 O2 sensor no signal intermittent

00513 engine speed sensor, no signal

repaired the repair which was done previously on the lambda connector

presumed the engine speed sensor was because of the engine not running when I plugged in machine

Cams(and lifters) were bought 2nd hand (5K usage) with gears and sensor ring fitted,

Had this issue with the old cams as well

got to love "SWAPTRONICS"

[J.C 10]

bad news, after further tesyts, it looks like the camshaft sensor is ok,

been up since 5am and traced and checked the wiring for MAF, throttle, idle valve, coilpack, camsensor, engine speed sensor, accelerator sensor, engine coolant sensor, injectors, IAT, IAC, Main engine earth.

checked operation of MAF, throttle position, Camsensor, IAT, ECT sensor.

before anyone asks, I havent VAG com'd it, my mate lives over an hour away, besides the symptoms havent changed since last scan,

previously ruled out includes

I have fitted new spark plugs and have tried brand new leads, No difference so refitted old ones.

spoke to the PO's garage and he said "that misfire" as if he knew I had a misfire, so I suspect it's been an ongoing problem as he said he's replaced leads, plugs and coil.

if anyone near St.albans can help me with either VAG COM, ECU, Coilpack,

there seems to be two issues,

1 Misfire seems to mainly under 2400rpm

2 Vibration up to 1600rpm

if it's not ECU or coilpack then I'm thinking it's bad news like sticking valve, bottom end IE mechanical (I'm an Electrical Engineer and don't like getting oily;))

I'm thinking of cutting my loses and fitting a 24valve lump but possibly do it while keeping VR6 12V ancillaries IE just use the 24V block

[Stonejag 10]

I'm in Harpenden with Vag-com, and not doing anything tomorrow. Drop me a PM and you can come round...(or I can come round!)

 

Not used it for a while, might take a little while to get it all working again but it's free :)

 

[edit: my coilpack is known-good, can always swap it on to try...got a few other spares I can bring, cam sensors etc?]

Edited May 31, 2013 by Stonejag

[Stonejag 10]

So, we've had a play around today, including a back-to-back comparison of mine vs Steve's. Clearing all the faults on VAG-COM and going for a spirited drive made no codes appear. Swapping for my spare coilpack didn't help, and neither did new leads. The cam-sensor, MAF and throttle pot all cause the engine to misbehave as you would expect when unplugged. We think we eliminated timing as it occurs at all rev ranges.

 

So, sadly it looks like valvetrain damage (bent spring? sticky valve?) or possibly something with the chains - the top tensioner is known to be a little dicky so that could be part of it. Fingers crossed for a healthy VR when he gets it inspected on Tuesday! :thumbleft:

 

Nick

[J.C 10]

Thanks for your help today Nick,

Was good fun chatting and playing Corrados,

I think I'm going to have to call on you computer expertise to get my VAG COM working, they were the setting I was using!!!! would be good to find out why the timing was changing between 3 and 6 degrees at idle.

developed a misfire on the way home when under load, turned out to be a loose lead but did make me realise mine HASN"T got a misfire but more like a murmur, might check out the ISV on Monday

D day will be Tuesday,

[Stonejag 10]

Yeah, it's the same symptom as I had when my coilpack first started going - it would misfire 'properly' if it was raining, and act like yours when it was sunny. Simple test for VR6 misfiring:

1) Does it sound like a bag of bolts put through a washing machine? - 2 cylinders misfiring

2) Does it sound like a Subaru? - 1 cylinder misfiring

3) Does it sound expensive? - not misfiring ;)

 

Great fun earlier, I'm getting a bit more excited about my 263s now!