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Garage => Mechanicals => Topic started by: s class on 19 October 2015, 04:52 AM

Title: My K-jet test bench
Post by: s class on 19 October 2015, 04:52 AM
For some years now I've been scheming to build a test bench for K and KE fuel injection.  The key requirements were :

- a complete system as would be found on a car
- ability to simulate cold start conditions
- ability to simulate warm-running coasting conditions
- ability to simulate acceleration conditions
- ability to measure and calibrate warm-up regulator setings
- ability to assess and balance fuel distributor flow rates
- ability to assess injector spray patterns and shut-off ability.

so we put this together recently :

welding completed, piping not done yet :

(http://i54.photobucket.com/albums/g85/mercedes_s_class/tools/IMG-20151011-WA0003_zpsi80nywsn.jpg)

Piping in progress :

(http://i54.photobucket.com/albums/g85/mercedes_s_class/tools/IMG-20151012-WA0007_zpsm0v8a6ac.jpg)
Title: Re: My K-jet test bench
Post by: beagle2022 on 19 October 2015, 05:10 AM
Wow!! Respect!  All you need now is a random set of vacuum connections to unknown objects obscured by years of gunk.
Title: Re: My K-jet test bench
Post by: revilla on 19 October 2015, 06:03 AM
Neat !!!  Looks great !!

In order to simulate cold-to-op-temp profile, are you planning to somehow heat up the WUR?  If yes, how in your setup?

Your fixture would have saved me all those hours I spent setting up my K-jetronic system some time ago.  In the 280SE, as most of you know, the WUR is mounted to the block just under the intake manifold.  So access is painful to say the least.  Each trial requires the WUR to be dismounted, adjusted, remounted.  Repeat the previous cycle as many times as needed for the CP, SP and static pressure to come to spec. 

The reward came eventually after all those hours when finally the car started with one quick crank both in cold and hot conditions.  I hope it remains like that for many many years or I might need your great fixture next time :)

Title: Re: My K-jet test bench
Post by: s class on 19 October 2015, 06:12 AM
INdeed, the misery of doing M110 WUR's had a lot to do with encouraging me to go this route. 

I have now wired in electrical circuits to energise the WUR heater coil.  Works well, just to make sure its properly up to temp, I use a heat gun on the body of the WUR.  You can see the thick piece of mild steel the WUR is mounted on, it provides a bit of thermal hysteresis. 
Title: Re: My K-jet test bench
Post by: revilla on 19 October 2015, 06:33 AM
Excellent.  Looking forward to the end product and pics.  Good luck.  I think If I have to do the WUR adjustment in my other M110 I might consider shipping it to South Africa instead :)  Sounds like business potential for you :)
Title: Re: My K-jet test bench
Post by: djenka018 on 20 October 2015, 09:35 PM
Quote from: beagle2022 on 19 October 2015, 05:10 AM
Wow!! Respect!  All you need now is a random set of vacuum connections to unknown objects obscured by years of gunk.

I LOL for 10 minutes after reading this comment...
thanks for making my day happier

Quote from: s class on 19 October 2015, 06:12 AM
INdeed, the misery of doing M110 WUR's had a lot to do with encouraging me to go this route. 

I have now wired in electrical circuits to energise the WUR heater coil.  Works well, just to make sure its properly up to temp, I use a heat gun on the body of the WUR.  You can see the thick piece of mild steel the WUR is mounted on, it provides a bit of thermal hysteresis.

on my long term list I have a plan for a similar jig .
This may push me to do it sooner rather then later. thanks.

The plate is not needed if you plan to connect the WUR to power.
internal heater is enough.
To replicate warm engine just preheat WUR electrically and leave it connected.
Title: Re: My K-jet test bench
Post by: s class on 21 October 2015, 03:14 AM
Yes, I do keep the coil energised during the warm-simulation.  It does seem to be adequate, but I like to be thorough, hence the plate.  In hindsight, as you suggest, its probably not needed.
Title: Re: My K-jet test bench
Post by: ptashek on 21 October 2015, 06:49 AM
Quote from: s class on 21 October 2015, 03:14 AM
Yes, I do keep the coil energised during the warm-simulation.  It does seem to be adequate, but I like to be thorough, hence the plate.  In hindsight, as you suggest, its probably not needed.

Next step, open source the design :)