K-Jet Fuel Pressure Testing 

Nice 👍🏻 glad it helped.

Thanks 👍🏻. I appreciate the feedback.

@@RetroVW If you were a teacher in a school, your students would be excellent because it is not what the teacher knows but how to convey it. if you have other videos for kjetronic please let me know where can i see them thank you

Matthew Gwatkin thanks, hope it helps 👍🏻

@@RetroVW hopefulk moving onto my next mk2 project very soon. meanwhile keeping busy on my vr6 corrado. keep up the top video's chaps 👍

Thanks and sorry for the slow reply. You may have already sorted it by now but from a 16v troubleshooting guide I have, backfiring under load could be a number of things, to check: - Sensor plate and/or plunger in metering head not moving freely. - leaks in air intake system. - Electric fuel pump not operating correctly. - Excessive fuel delivery in control circuit. - Warm control pressure too high/too low Those are to name a few things to check. Good luck and post back if you are still having issues 👍🏻

@@RetroVW THANKS a BUNCH for your comments, Retro! Your reply timing is fine, as I've not been able to work on it since my first post. The car is a "sentimental vehicle", stored in a conditioned garage space quite remote from my house. I'm hoping to make the road trip to it in the next couple weeks, so your timing was perfect. First move is: I'll try cranking it to see how it behaves "totally cold", as the backfiring episode started on a summer day and after the car had been fully warmed up by driving around. If it runs "ok" cold, that would point to the Warm Control Pressure as the culprit................which I believe is also affected by the "Idle Control Valve". As I recall, the backfiring was MOSTLY at idle, and was not an issue if I kept the engine revved up at stoplights. I'll also check over the rubber boots more carefully next visit, and then pull off the one above the sensor plate to check for binding.

@@panchitox8875 great! Hope you manage to get to the bottom of it. Maybe stick some fresh fuel in also if its been sat for a while 👍🏻

@@RetroVW Thanks for the suggestion, Retro, but I had just added some FRESH non-Ethanol before driving it that day. Since it's garaged in an enclosed, semi-conditioned space, I don't have to worry TOO much about "condensation" gathering in the tank....so I tend to keep the fuel level low so that it's easy to "re-fresh the fuel" time to time by adding a couple of gallons. HOWEVER, if I don't find a cracked boot or binding air sensor plate I plan to add ANOTHER couple gallons of FRESH non-ethanol since it is possible that I got "bad fuel" at the station.......because I drove it to the station just fine, then added fuel............I then drove it several more miles and made another stop to make a quick purchase. It was running just fine all the while, until I RESTARTED a few minutes later to return it to the storage garage. Backfiring ensued, and I kept feathering the throttle through all the "stoplights" for the couple miles of return trip keep it running. I was pressed for time that day, and only pulled it into the storage space, shut it down, and lock it up. Sorry for the long reply, but just adding some additional BACKGROUND in case it sparks any other thoughts!

@@panchitox8875 Ok great! so fuel is new then, though it could be a bad batch of fuel since you mentioned the backfiring started shortly after refuelling at the station. I think essentially on these cars you need to have a KJet Fuel pressure gauge really to properly check and set them up. So I would say you would need to check the fuel pressures to make sure it is all set up correctly and that both System and Control pressures are correct. Also make sure your injectors are working good and evenly balanced, I have another video on how to check the injectors here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-aDmavXtSi88.html Hope this helps.

I covered it with a foil type cap I happened to have handy just to keep the dust out. It sits tight against the engine block anyway so should be fine. Hot start could be a bad fuel accumulator. You could check this by seeing if the system holds pressure for 20 mins after you turn off the engine. Ive also read that if you loosen the screw from the back of the accumulator, if fuel comes out then the internal diaphragm is shot meaning its not going to hold pressure. Good luck with the troubleshooting 👍🏻

Thanks 👍 I bought my pressure test kit from a guy on ebay who made the kits himself specific for the CIS Injection on VW Golfs, XR3i etc. I think his name was jamesccbarratt, but looking online I'm not sure he has any for sale anymore. Maybe take a look on ebay to see if anyone else are making kits. If I can find the specs anywhere I will reply back to this post.

Nice! Yes, you definitely need a fuel pressure guage to be able to set these up correctly. The fuel pressure gauge I found on ebay as there was a guy on there who made these, he was selling them for around £60 if I remember correctly. I don't think he is selling them anymore, but I'm sure you could grab the parts online somewhere and make one up as there's not much to it. I think the only difficulty would be sourcing the correct screw fittings for the metering head and fuel lines, but you can probably find this information out from forums. In fact, since making my video a fellow RU-vidr has listed all the parts needed to make your own, if you check out the description on Grey Goose’s video here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-QlHwmzVmcgI.html

@@RetroVW Much appreciated - I will look into making one! Thanks for your help.

j1mveedubu thanks 👍🏻 when I first got the car I had the engine out and restored the subframe and running gear along with respraying the engine bay in VW Campanella White to give it a fresh clean look. The rest is just general cleaning as it all went back in.

RetroVW nice one, I’m in the process of tarting my 16v engine bay as the external is in good condition but engine bay is letting my mk2 down. Basically adding to the list. 😉

j1mveedubu cool! Good luck with it. I bet it will look mint when you’ve done it.

RetroVW the manifold is in great condition but just need a decent cleaning product , but new fuel lines are needed, the common corroded lines. Are you on instagram?j1m_mk2 if you are.😉

Thanks 👍 The fuel pressure gauge I found on ebay as there was a guy on there who made these, he was selling them for around £60 if I remember correctly. I don't think he is selling them anymore, but I'm sure you could grab the parts online somewhere and make one up as there's not much to it. I think the only difficulty would be sourcing the correct screw fittings for the metering head and fuel lines, but you can probably find this information out from forums. Same here.. the Golf runs ok but I'm sure that its doing mid to low 20's for mpg, lol. I'm pretty confident my fuel pressures are now correct so maybe CO adjustment is next on my list. Good luck with it 😀

He tested the accumulator by seeing if the pressure remains above 2 bar 20 minutes after shutdown, since that is the job of the accumulator, and if the accumulator isnt working as it should it can mess with the pressures

Steven Harper thanks 😀

Thanks. I think its around 2% CO.

get on the club gti forum, there is a sub section for the kjet injection system and loads of great advice and experience on there

??

I will see what I can do, although I dont have access to a gas tester to measure CO accurately. But there is a basic setup that you can do to get it setup pretty close.

Are there any DIY methods one can use to measure CO, if so what are they? a wideband wont work i'm guessing?

Yes, I did this whilst the car was warmed up then adjusted.

System pressure is adjusted by adding or removing shims on the valve screwed into the side of the metering head. Control pressure is done as shown in the video by adjusting it on the Warm Up Regulator.

I drilled the hole to for adjusting the pressure on full load. Now I have lambda 0.86!

full load or full throttle, I don't know how to say it correctly but I think you understand me.

Thanks for the comments 😀 There was a break in the wire connection that was causing zero voltage, I mentioned this in the video at 9:47, which I repaired before continuing with the test. This was one of my early videos so maybe not the clearest of explanations 😆 Thanks and stay safe.

@@RetroVW can i whatsupp you?

@@wesleysmal9 What's your question? if you post here I can try to help, or perhaps the community can help also.

Not off the top of my head but I think I have some thread pitch gauges somewhere. I will dig them out and try to measure the dimensions for you 👍🏻

@@RetroVW M12x1.5, source ClubGTi and my KR 16v... just popped out to the shed and measured it. There are lots of different thread sizes across the whole K-Jet range of application, VW, Porsche, Merc and so on. You often hear stories of guys buying gauges online that say it fits K-Jet and then finding that it does not fit their vehicle.

The engine was cold when I started the initial test. I then monitored the change in control pressure as the engine warmed up.

It’s best to measure the thread dimensions on the male connection on your fuel distributor. There are lots of different thread sizes and pitches used in K-Jet applications across the different manufacturers, I have some here from MK1 and MK2 GTis and Audis and they are all slightly different.

@@English_Speaking_Fox brilliant thank you for that mate 👍👍

Daniel Neves thanks ;-). Its a KR engine with standard K-Jet.

Hi, I managed to find this one for sale on ebay here in the UK, but don’t think the seller I bought mine from sells these anymore. If you take a look over at Grey Goose channel youtube.com/@GreyGooseRestorations he has a video where he makes one so might give you some ideas on what to buy 👍🏻

Hi, I dont have access to my test kit at the minute to double check, but there's a CIS fuel pressure guage listed here that mentions the thread sizes if it helps: www.kurth-classics-autoparts.de/gb/warm-up-regulator-wur/227-k-jetronic-pressure-testing-gauge.html Also, the following may help: Injector lines & 5th injector - M8x1 WUR return line - M10x1 ? main pump banjo - M12x1.5 fuel filter input - M14x1.5 fuel filter output - M12x1.5 metering head wur line - M12x1.5 metering head main in/out - M12x1.5 main fuel lines - M12x1.5 accumulator output - M14x1.5 Maybe double check these sizes though before you order any fittings.

Thomas Morgan there used to be a guy who made and sold them on ebay. Not sure if he’s still selling them or not.