Corrado 24v misfire - help please

[quicky1980 0]

hmm, ok sounds like fuel is less likely now then. but i dont treat my engine as well as you and have been using cheapo tesco fuel. I'll still try the swap for fresh stuff, if that fails then I'll take you kind offer up to come look at the car with me. of course I will still cover costs.

[Dox 23]

IIRC, he has a MK5 engine which came with the upgraded chains from the factory. That check is only relevant to MK4s. Good shout though.

 

Sam, my V power was over 6 months old when I fired my R32 up for the first time and that DEFO loses octane, but it ran peachy :D

 

I wasn't saying there could be a chain issue, just that the 2 cam sensor signals could be viewed with VCDS to check there operation. The sensors are the same part number too, so if there was an suspected issue with lets say the inlet, then swapping them inlet to exh and vise versa if the code changed with the swap out then it could confirm a sensor to be at fault without shelling out on a sensor?

[quicky1980 0]

Will give that a try dox. Looks like -+8 is the limit. Presumably under idle conditions.

[quicky1980 0]

well, ive emptied the tank (as best as I could) and filled a third of the tank with fresh BP ultimate 97ron and still issues. the drive to the petrol station was fun. at first the car isnt happy to drive but tends to clear itself up however when i hit 4000rpm there is a very severe misfire. If I dont back of at 4k the car goese into shut down ie running on one injector.

 

Because of where i was I couldnt pull over so whilst coasting i shut down and restarted, all cylinders fired up but the car was as before ie poor running until clears it self.

 

Will be checking timing tomorrow but this is really really frustrating. I may take the plunge and try to drive the car to a specialist. SWICT are miles away, Jabbasport are round the corner and a vw specialist not much further. May even try to get it to Stealth. but all these options are gonna cost me.

[dragon green 5]

Did you keep your old coil packs ?

Have you tried putting the old ones back on ?

I've just read your thread,it must be so frustrating, chances are,it's something simple,but it's finding it to fix !

[quicky1980 0]

I still have 5 old ones (one gave up and I replaced all with new parts). will give it a try

[Kevin Bacon 5]

I haven't got much on this weekend so can drive up mate. I think it's worth at least giving a thorough going over with VAG-COM before splashing out some loot on the professionals.

 

I haven't done many long journeys in mine since the conversion, so a good excuse to get some proving miles under it's belt!

[quicky1980 0]

If you dont mind that would be excellent!! I just hope the weather holds off. I'm out on Sunday for a Christening so cant really pull out from that but Saturday I can be in all day. Ill pm you my details so we can arrange finer details, thanks!

[quicky1980 0]

Thanks Kev for coming round to try and problem solve. We found a few things such as cam sensor wires were wrong way around (always been like that!), fuel pressure should be at 3bar and not 4bar.

 

Lambda's are working as they should but the car still doesnt behave.

 

Kev, while I was putting the car back into the garage the misfire was back at 2000rpm. Not sure what you did to clear that issue, but maybe you simply cleared the faults?

 

The scans showed an issue with the engine speed sensor, something about implausible signal so will look to replace the crank sensor as this may be a potential root cause.

 

Couldnt take the car for a spin due the the gear mechanism breaking while Kev was round! so cant tell if the car simply needs a decent drive to resolve the issue.

 

the cam sensors being wrong way around is probably a red herring to the current fault but it is wierd how the car seemed to run and perform ok since the install.

[Kevin Bacon 5]

No worries mate. Always good to put a face to a name!

 

Yeah I would replace the crank sensor as it keeps coming up in the fault scans, which isn't a good sign! I think I was quote £75+VAT last time I enquired.

 

I don't understand the cam wiring thing either tbh, but all I do know is the cam angle readings then became what they should be when you swapped them round. Very odd!

 

I was happy with the lambda activity after it had adapted when you dropped the fuel pressure to 3 bar, so we just need to sort that funny misfire at 2K now.....

[24V Renshaw 0]

As I said in my first reply on this thread, I got these exact symptoms from the crank sensor so fingers crossed a new one solves it for you.

 

Jay

[Kevin Bacon 5]

Yeah you had to get that in didn't you? :D His isn't loose though. So it's either got swarf on it or the signal is intermittantly dropping out. It's very weird though as technically the engine shouldn't even run without a crank signal as the ECU no longer knows where TDC is. It can't be 'faking' a crank signal by using the cam sensors because we had both of those disconnected at one point and it still ran with a crank error!!

 

Oh well, replacing it should sort it one way or another.

 

I knew there was a reason why I stuck to the standalone when putting my R32 in! :lol:

[24V Renshaw 0]

LOL, well I refrained from writing "i told you so", but I told you so! :) :)

I think as the revs go up it works fine, then for whatever reason, be it swarf, or its loose, or faulty, then it does then doesn't and the ECU tries its hardest to keep things going by filling in the gaps maybe?

 

Nah OEM is the way forward, 2 mins on VAGCOM and its told you whats wrong :)

 

Jay

[quicky1980 0]

well I'll take the plunge. Was going to get the part number off the sensor yesterday but had chores to sort out. I hopefully can get underneath the car tonight and check it while recording the part number (vagcat isnt working at the moment and am at work so cant check ETKA).

 

I need to get a few parts from TPS anyway as the gear linkage broke while Kev was round mine. Also the audi didnt want to play ball and allow for a suspension swap as the main front bolt is stuck solid. Will need to get a new one incase the old one breaks as it comes off.

[RedTyphoon 0]

Im glad you getting somewhere to solve your problems. I have a spare crank sensor,so you can have it and try if thats hepls. Then you can buy a new one and keep this or returned it. I dont need it as Im using VR6 one.

Hope you will sort this soon.

[Kevin Bacon 5]

LOL, well I refrained from writing "i told you so", but I told you so! :) :)

I think as the revs go up it works fine, then for whatever reason, be it swarf, or its loose, or faulty, then it does then doesn't and the ECU tries its hardest to keep things going by filling in the gaps maybe?

 

God knows. I'd love to see what algorithms it uses for that. Maybe as you say it can guesstimate up to 2000rpm, then after that it gives up.

 

Nah OEM is the way forward, 2 mins on VAGCOM and its told you whats wrong :)

 

I have a MK5 ECU and loom in the modifying process as we speak, so I'll give you my thoughts on OEM management soon enough ;)

[quicky1980 0]

Red, if I could borrow it and as long as you know its working that would be excellent! Does anyone know if they are different depending if they are early or late engines?

[RedTyphoon 0]

I was working when I made up adaptor for VR6 connector,then I found out its same fitment,just different plug. Its of BUB engine 2009. Let me know your address and I will send it asap.

There is no number on it ,just vw audi.

Edited May 8, 2012 by RedTyphoon

[Kevin Bacon 5]

Does anyone know if they are different depending if they are early or late engines?

 

They're all the same sensor from 12V to R32, just different connectors.

[quicky1980 0]

sorry I should have been clearer in my original question. are the connections the same on these for all 24v engines? i dont want to hassle red only to find out it wont fit. my engine is bdb, iirc bub is an early arrangement?

 

red ill pm you my details now

[Kevin Bacon 5]

Mine's a BDB as well and I'm using a MK4 sensor, so that should answer your question ;)

[quicky1980 0]

Thanks Kev!

 

---------- Post added at 1:26 PM ---------- Previous post was at 12:40 PM ----------

 

Kev ive just had a thought, when we saw the error, Im sure it stated engine SPEED signal implausable (G28). Are we sure thats the crank sensor? I came across this

http://www.justanswer.com/audi/42lr3-audi-a3-3-2-v6-engine-speed-sensor-location.html

and it seems to point out the the speed sensor is on the gearbox, so for my conversion it makes sense that the error code comes up. so I think the crank sensor is working fine and hence why the car start up. otherwise i cant see how it would start or even run!?

 

---------- Post added at 1:29 PM ---------- Previous post was at 1:26 PM ----------

 

actually scrap that. another website states its on the front of the block near the oil filter which makes me think its the crank sensor after all.

[Kevin Bacon 5]

Yeah Sam, "Engine Speed" is indeed the crank sensor I'm afraid. "Vehicle speed" would be the gearbox sender, or in the case of the MK5/A3, signals from the ABS sensors.

[24V Renshaw 0]

Yep. G28 is the one on the front of the block. Held in by an M6 cap head from memory. Can be easily removed from under the car.

[quicky1980 0]

Thanks to David I have had chance to swap my sensor for his, was a little awkward to do and couldnt find the right allen key (found all the others but not the needed 5mm! why is that always the way!?)

 

Anyway. started her up and rev'd very well, no misfire. couldnt take her out for a drive but im confident the issue is down to the crank sensor so well done Jay!

 

Off to order a new one tomorrow but for the life of me I cant work out how the car started, idles and kinda ran with a duff crank sensor!? common knowledge suggest that the car needs a signal to know when to spark/inject etc and before someone sais it relies on the cam sensors, these were both disconnected at one point and it still ran.

 

So maybe the sensor was partially working or a a poor earth (presume the fixing bolt acts as an earth through the sensor?)

 

Will play around with my old one a little before fitting a brand new one but fingers crossed this was the issue. yipee!!!

 

thanks again to all (esp Dave for the lend and Kev for coming up from Essex), if you dont hear anything further on this post it was definitely the sensor in some manner.