Bosch KE-jetronic - System Pressure Testing

#car #music #kjetronic
Finally managed to make a start on the CIS-E or KE-jetronic series of videos, its taken a long time but these systems aren't as common as the older K-jetronic so its not often i have a unit in to rebuild and test.
System pressure should always be 0.4 bar higher than the differential pressure, thats the magic number you want
Residual pressure should be in the region of 2.6 bar after 10 minutes
We will investigate more with the inside truth video
Help support the channel here
/ @greygooserestorations
Plus get your technical manuals cheaper here
Link to eManualOnline plus use code GREYGOOSE22 for 22% off site wide
shareasale.com...

[@jasonbirch1182]

Vacuum port is so the inner diaphragm can work without being in a sealed can, and the engine will drink the fuel if it ruptures rather than spray fuel around the engine bay.

[@GreyGooseRestorations]

That makes sense, thanks

[@danielclare2344]

Chasing a hot start issue on 9a corrado . It’s like loosing fuel pressure when parked . Love to have your understanding of the system 🤣

[@GreyGooseRestorations]

Could be a number of things, fuel Accumulator failing or one or more of the seals in the metering head, or if KE then the external fuel pressure regulator

[@JhnStill]

Great explanation, Thank you very much sir

[@danielclare2344]

Great video

[@iwillbuycocainefromyou]

good stuff, cant wait to refresh my audi from top to bottom this summer.

[@mcfly6667]

Another great video Thank you.

[@GreyGooseRestorations]

Thanks for your support 👍

[@user-gv2hj3jq1n]

Hi when are you posting the next video on these ? I have one on an rs turbo that fires up then cuts out so interested in learning more cheers

[@paulleslie9110]

Me too , did u ever sort it?

[@user-gv2hj3jq1n]

@@paulleslie9110 yes I did one problem was the fuel pump relay I bypassed that then balanced the fuel pressures and it stated to fire the injectors

[@wsmallridge]

Do you think the vacuum on the fuel pressure regulator might have something to do with a reference for boosted applications ?

[@GreyGooseRestorations]

Potentially 🤔 i may have to cut one apart and see what's inside

[@TruckerKingJM]

How is it going with the videos about the KE-Jet? Summer is on it's way and time for classic VAG-cars from the late 80's to mid 90's agan....;)

[@GreyGooseRestorations]

Close just need to put it all together

[@TruckerKingJM]

@@GreyGooseRestorations Looking forward to that!👍

[@AlvarVadi]

Hello, i need desperately help with my Ke-jetronic. I have residual pressure ok but right after i turn off ignition pressure drops to zero. When i clamp return hose the pressure remains. Is the head leaking or where the is the leak?

[@GreyGooseRestorations]

If you clamp the return hose and pressure remains, then your issue is the fuel pressure regulator itself and would need replacing

[@user-gv2hj3jq1n]

Hi when are you posting the next video on these ? I have one on an rs turbo that fires up then cuts out so interested in learning how they work

[@rn-j7600]

Hi mr Goose, i have a Ke jetronic on my audi 80 and it keeps searching for its revs at idles by about 400rpm up and down. Have vacuum tested and all good so mechanic thinks fueling. Any ideas? Thanks

[@Random-nf7qb]

9A is KE-Motronic, not a big difference, but still

[@GreyGooseRestorations]

Correct but for pressure testing theres no difference

[@arthurkabian9301]

System pressure is adjustable by screwing in or out on the valve to achieve 6.2 bar, What if the diffrential pressure is not 5.8 bar? How do you adjust that to make it 5.8?

[@GreyGooseRestorations]

If the differential pressure can't be made to have 0.4 bar less than the system by adjusting the fuel pressure regulator, then adjustments can be made to the DPR unit, theres another video coming out soon focusing on that alone

[@arthurkabian9301]

Thank you

[@adeloro6879]

@@GreyGooseRestorationswhat size hex key do you use to adjust the FPR?

[@johnburketransport]

When adjusting the pressure regulator, I found that turning the Allen key screw inwards(clockwise), increases the pressure. That is the opposite to your statement.

[@martinburke3755]

Hi guys, Love the video!!! Knew I saw this adjustment in a video a few months ago and in the first second seeing this tonight I knew this was it :) My question... When I undone the adjustment line the tiniest dribble of petrol came out, not even a thimble, is that a sign of a gonner or can it retain a minute amount? It's running at the high 6.4/6.5 and 6.8/6.9 with line open, Mercedes 420SE, Going to aim for the 5.9/6Bar, Going to find the allen for it tomorrow, my current set starts skipping sizes so not feeing a bite it must be one I don't have, maybe a 6mm, I'll update when I'm done :) The symptoms on this was a rich smell and a slightly pulsating engine with weaker than normal acceleration, no smoke but a slightly vapour rich exhaust (visible at night anyway), Have a few KE jet Mercs so getting to know them well, 1 in particular is educating me no end, only thing right with that one is its fuel pressure! :)

[@GreyGooseRestorations]

Hi, do you mean the fuel return line off the back of the fuel pressure regulator? If so then once the system is pressurised and then switched off Taking off the return line the FPR should have next to no leak, only a dribble on disconnecting, if it continues to leak then yes it's failing

[@martinburke3755]

@@GreyGooseRestorations Great news, thanks again GreyGoose!! sorry, yes, the fuel return line off the back of the fuel pressure regulator, Sounds like turning it down should solve the issues :) all the way clockwise, hit the 6Bar... simples :)

[@martinburke3755]

Hi all, Today I went at it and a 5mm too large in situ, 4mm too small, must be imperial, I removed the regulator and a 5mm just about got it, turned full clockwise and on starting the pressure went over 9Bar, turned it off quick, going to get a 4.5mm tomorrow and be able change it in situ rather than taking it off every time, I'll update tomorrow, hoping nothing gave up with the high pressure instant :/ still only a thimble worth of fuel when disconnecting the fuel return line so hoping for the best!!

[@martinburke3755]

I got an imperial allen key set but the 5mm seemed to be the size, just ridiculously tight, Got it turned back again that it now is at the 6.3bar, anticlockwise reduces pressure on mine as someone else thought, Now it starts but when shut off the fuel pressure goes from 6.3bar to 2bar in no time, a bit worried that the instant of high pressure popped the injectors or distributor because it was holding good pressure before. Could it be the fuel pressure damper leaving the pressure in the system drop so quick?

[@GreyGooseRestorations]

@martinburke3755 yes the fuel regulator holds the residual pressure, is any fuel getting into the other end where the vacuum line is

[@RudeLubeuk]

Hey Mr Goose, your discount code doesn't work for emanuals online, I just want wiring diagram for a 1982 mk1 golf gti, I can't work out which haynes manual I need 😭

[@GreyGooseRestorations]

Ok ill see whats occurring

[@JhnStill]

Hello Mr Goose, I Hope that you are doing well, I Tried to adjust the fuel pressure regulator on my 190e (had a pressure of 4.6 and tried to make it 5.3 as in specs) but now there is no fuel going to the injectors, also when i connect the barometer and run the fuel pump the pressure is steady around 5.6 but then i hear a click sound coming from the fuel pressure regulator and it goes down to 5.1 instantly after that, did i break it or is this normal? Also when i disconnect the return line while the pump is running i get huge amounts of fuel coming out of the regulator, are you talking about no leaks from the return line after the pump stops pumping or while its still pumping? Thank you very much

[@GreyGooseRestorations]

Hmm it may be that the pressure regulator is adjusted close to its limit so as soon as it gets to the point of opening it stays open like its stuck, you shouldn't be getting large amounts of fuel out. Prime the system then switch off and take off the return line off pressure regulator, it should be wet but not letting anything past

[@JhnStill]

@@GreyGooseRestorations thank you so much for the information and explanation you provide, i will try it asap and get back with the verdict 😀

[@JhnStill]

@@GreyGooseRestorations your diagnosis of the problem was on accurate, i reduced the system pressure in the pressure regulator and now i have fuel in the injectors, i think my pressure regulator needs to be replaced since it cant get the proper system pressure. Thank you very much for your help 🙏

[@GreyGooseRestorations]

@JhnStill happy to help 👍

[@forresttucker168]

Does the KE jetronic have enough adjustment in fuel delivery to run a turbo on an NA engine, no more than .5 bar .

[@GreyGooseRestorations]

Yes it has enough capacity to fuel turbo 👍

[@forresttucker168]

@@GreyGooseRestorations I assume these same techniques will work on a 1992 Mercedes 190E running KE-Jetronic system.

[@GreyGooseRestorations]

@forresttucker168, in theory, yes once system pressure is set then its a balancing act to get the desired flow

[@forresttucker168]

@GreyGooseRestorations so I need to invest in a fuel pressure gauge, a wideband oxygen sensor, and a water methanol injection kit.

[@forresttucker168]

Is there a CIS specific fuel pressure tester I need to get, or will any one do?

[@Morphasella]

I don't understand the logic, the flow route, why open valve will make 6.2bar and close valve will make 5.8bar?

[@GreyGooseRestorations]

System pressure vs differential pressure Similar to k-jetronic System pressure vs control pressure

[@user-gv2hj3jq1n]

Hi when are you posting the next video on these ? I have one on an rs turbo that fires up then cuts out so interested in learning more cheers

[@rudyperalta3147]

Hello Sr I have a 1980 Porsche 924 turbo and after rebuilding the fuel distributor the rpm’s seem to be a lot higher did I do something wrong? And also it has a hot start problem any help would be appreciated thanks

[@GreyGooseRestorations]

As in the engine revs higher or the idle level is higher. Did it have the hot start issue before

[@rudyperalta3147]

@@GreyGooseRestorations yes it did I would drive it somewhere and go do what ever and when I came back it would not start so then I rebuilt the fuel distributor it runs better but I don’t drive it somewhere where I’m going to take long because you know. It will start the next day

[@GreyGooseRestorations]

@rudyperalta3147 that sounds like the fuel Accumulator that's not holding pressure potentially

[@rudyperalta3147]

@@GreyGooseRestorations oh wow and I replaced that too the old one was leaking gas,maybe it’s faulty

[@GreyGooseRestorations]

@rudyperalta3147 ok if its a bosch part chances are its somting else It could also be fuel pump check valve Or the main seal on thr pressure relief valve in the metering head or the CO mixture set to rich so once engine is switched off pressure is leaking away