Hi peeps>>> my old mk2 sounds like its pinking slightly when accelerating. I had to pop the dizzy off recently and therefore re-set the timing to 6 degrees BDTC. Its also idling slightly too fast approx 1100 despite turning the idle valve on the TB & continually running fast even after the engine is warm, so wondering if the WUR is playing up? Its been doing this since it was garaged for almost a year. I'm running a 2E 2.0L bottom end with a modified cam & some head work/ branch etc. Thanx
Get a knock sensor ignition set upm from an Audi, knock sensor, distributor & wiring, and ignition box from a wreckers yard. Jase
I had pinking on light throttle with a similar spec engine. Try disconnecting the vac advance from the dizzy. I gained fuel economy, a bit of power, and stopped the pinking by doing this. Basically if you're using the old kjet dizzy, it's a fairly safe bet that it's advance curve no longer suits the engine, as it has been modified. There are places that can recalibrate them to suit your spec.
Tried disconnecting the vac advance pipe but still making a slight pinking noise. I have a timing gun so may tinker with the timing to see if it improves..... Any other tips appreciated
to start with get the fuel pressures tested to see if its working right, also a fuel injector spray/delivery test is a good plan
Awaiting your input rubjonny Replaced all injectors around 1500miles ago - will check on fuel pressures - is there a DIY method to perform this or do I need to locate a garage with special calibration equipment? Completing the old injectors in the jam jar technique will only indicate volume/ spray pattern and not pressure accurately? - please advise... thanx
It's probably too lean. I bought a car with a similar spec engine on standard 8v kjet and it was running far too lean. The timing was backed way off to stop it from pinking. If you back off the timing that will avoid damaging your engine in the short term, but the root of the problem is probably that you're not getting enough fuel into the combustion chambers. The quickest way to improve your problem is probably to fit a 16v WUR, which will increase the fuelling, or by adjusting the fuelling at the metering head to increase the pressure.
if the injectors are new then they should be alright, move onto pressure and mixture checks adjusting the mixture could only end up working around a pressure issue, so if you can get some pressure gauges its well worth it. you can knock a set together diy, theres a good set o pics in the WUR mod how2, plus heres some guides: http://vwtech.no-ip.info/downloads/k-jetpressuretests.pdf http://vwtech.no-ip.info/downloads/k-jetfactorymanual.pdf
Where are you based? If you're near Stealth or TSR, they could sort it out for you. If you prefer to DIY, you need a fuel pressure gauge and/or a wideband lambda meter to sort it properly, and get more power from your engine.
The thought did cross my mind that this maybe the case. On rebuilding the original 1.8l 8v motor with a few additional tweaks the fueling was reset at the garage because it was found to be running too lean. I assumed the setp would be fine upgrading to a 2.0l with a modified cam. Research indicates the k-jet system can handle fueling to 200bhp (not sure on the spec/ modifications to achieve that figure though 8v or 16v?) and mines running approx 135bhp. Would the 8v WUR be sufficient once adjusted for this power? Funny thing is I only noticed the pinking once the old exhaust was upgraded. Thanx Mike
Cheers for the K-jet info - have sourced documents over the years but these have eluded me! Unfortunately Stealth & TSR are slightly too far away maybe I should state my location in my profile. Thanx for tips and pointers once again...
The standard 8v kjet is set for 112bhp. The 200 bhp engines were running with 16v kit, which has been modified to flow more fuel. The garage probably only adjusted the idle mixture, using the screw on the metering head. I think you can adjust the 8v WUR by pushing in the little plunger on the front, but I've never tried it. (It looks like a kjet 911 WUR, which you adjust like that.) You'd still be better off with a 16v one, as it uses vacuum pull to increase the fuel pressure at the top end, and with the breathing mods on your engine, you'll need more fuel at the top end in particular.
Dizzy dictated spark timing is not ideal on a std 2E/Kjet engine and even worse if the aircharge is altered with a cam. 16v WUR does help the crap mixture profile through out the rev range but again not ideal. To get the mixture nearer to correct you would need to get a bit advanced and adjust the jets in the metering head with extra head room giving by WUR mod or 16v WUR. Else take a big hammer to the system and run a standalone.
Standalone would obviously better, but if the aim is to get it running as well as possible on a 'near OEM' system, then a 16v WUR will help a lot. It's a blunt instrument, but a blunt instrument of roughly the right size, as opposed to tunnelling out of prison with a teaspoon. You can't mod the 8v WUR in the same way as the 16v - push the plunger in to make it run richer, I think. If you want to push it back out, you have to strip the WUR down and do it from inside.
Absorbed all that info - will look into sourcing a 16v WUR as opposed to a new management system. Any big upgrades in the future will be a 1.8t & that will not be happening anytime soon. Thanx & have a good weekend!
