what i want to do

[richard s]

i have a 86 mercedes 2.3 16v cosworth and it has kjet injection that has a problem so have been reading up and i want to efi it i know roughly what needs doing (trigger injectors fuelrail) its the wiring and ecu part that i need to learn more about so i thought i would ask you guys for some help
i know i need air temp coolant temp throttle position sensors for a start but what other sensors will i need
this is my first post so i will not go into overload on my first outing
cheers
 

[rob@vems.co.uk]

The vital sensor is the crank trigger sensor.

Next up is the air temperature and pressure sensor sensors are next.  We tend to use a built-in sensor as its new, noise free and easy to connect.  The air temperature sensor

This gives you the speed density (engine speed, air temp and pressure giving density) for fuel and ignition.

After that you get the sensors that do the enrichment sensors - Throttle position sensor and coolant temp sensor.
The throttle position is monitored for acceleration enrichment.  The coolant is used to calculate the warm-up enrichment (choke).

Then we have the Wideband sensor which monitors the AFR its great for tuning and closed-loop feedback when running.

You also have the option of knock and EGT sensors but these are not of concern at the moment

[richard s]

for crank trigger i have been advised to use a honeywell gt101 hall sensor and 2 bolts set 180degrees apart as this is the most simple setup and the hall sensor does not pick up noise like vr ones
the air temp and pressure sensor is this 1 unit or 2 and where in the inlet would it/these be fitted
cheers

[rob@vems.co.uk]

I've been on at my mate who's a machinist to make some of these:

(Although possibly with thicker teeth)

If we're going crank mounted then a 12-1 or some such would be good too.

Honeywell GT101's are good quality, cheap, and have the noise advantage that you've mentioned.

Air temp sensor is a single unit with a 14x1.5mm thread, the MAP sensor is built-in to the ECU (although there is an external sensor that we can use) and it requires a tube to be run from the plenum to the ECU

[Chris Martens]

Richard,

something like that should do it:



Looks like the Hall sensor in a bracket and two steel bolts. If you wand it simple and working, that's the way, I think.



Bracket should be strong!

Of course there are nicer looking solutions, like the one, Rob showed.
It depends on what you want.

BTW I own a 1984 190E 2.3-16 (look at my avatar) that will most probably get a VEMS during next(!) Winter (2008/2009).
So the old girl will have a strong heart for her 25th birthday.

regards,
Christian

[richard s]

cheers for the pics chris i have been sent the bottom one before on a different forum by the guy who did it as i couldnt understand what he meant with a description but as a trigger i think that is simply genius providing you get all your workings out right

rob i thought that map sensors were only used on turbo cars 

[rob@vems.co.uk]

If you're going to the trouble of making up all the bits for a crank sensor I'd personally at least attempt to get a missing tooth setup running so that you can run a coil pack or other form of direct ignition.

A MAP sensor is used with Normally Aspirated engines too, Speed Density (MAP, Air temp and RPM) is a much better fuelling method than AlphaN (Throttle position and RPM).  As long as you're not running individual throttle bodies using MAP is trivial.

[Chris Martens]

Rob,

AFAIK there is no problem to run a WS setup with this "2-tooth-trigger" - if you really want to toss the original distributor setup.

regards,
Christian

[rob@vems.co.uk]

How do you know which tooth is cylinder1 BDC and which is cylinder 1 TDC?
Unless there is cam trigger, in which case this is an excellent trigger pattern.
Rob

[Chris Martens]

yes, you are right.

Christian

[richard s]

i am going on what i have been told is the easiest option because i started out thinking along the lines of the 32-1 ford edis set up but was told that the 2 bolt was easiest way to do it
i was told turn between 40-90 degrees btdc mount sensor drill and fit bolt then fit other bolt 180 degrees away and that would give tia between 40-90
and the distribotor just puts out spark as there is nothing inside it needs removing
drill a hole in the dizzy cap at no1 and use a timing light
this is a shorter version of what i have been told works well on the mercedes but i am open to all possibilities as i am learning as i go

[richard s]

rob the map sensor in the ecu that needs a tube to the plenum and the external sensor mentioned do you need both or will either do
cheers

[rob@vems.co.uk]

i am going on what i have been told is the easiest option because i started out thinking along the lines of the 32-1 ford edis set up but was told that the 2 bolt was easiest way to do it
i was told turn between 40-90 degrees btdc mount sensor drill and fit bolt then fit other bolt 180 degrees away and that would give tia between 40-90
and the distribotor just puts out spark as there is nothing inside it needs removing
drill a hole in the dizzy cap at no1 and use a timing light
this is a shorter version of what i have been told works well on the mercedes but i am open to all possibilities as i am learning as i go

I am a great believer in "Perfect is the enemy of good enough" I'm just trying to work out what level of good enough to aim for

I'll be talking to Jorgen this weekend and get the run down on what he reckons is the optimum setup.

[richard s]

done a bit of reading on the int/ext map sensor and i think i would prefer to run external map as i think a vacuum pipe running into the car would be easier to damage than one that is shorter and bolted to the inner wing/bulkhead etc so apart from the vacuum pipe how much wiring is involved and how easy is it to set up

also when reading i came across a section about trigger wheels etc and it mentioned the ford 36-1 not 32-1 it also mentioned 60-2 so what would be the better option of the two and do both run wasted spark also can both work off the gt101 sensor or do they have to use vr sensors
cheers

[Chris Martens]

Richard,

sounds like you're telling from Jesper / Racing, looks like it's his setup, I posted the pictures of his work...

An additional question for the "best setup" would be: what's your goal?
Do you want the nicest technical solution?
The cleanest looking solution?
The easiest / cost minimized solution?

The answer will depend on your goal, I think.
It also depends on the shape of your current ignition system, if you need new wires, wire plugs, distributor cap, finger, maybe the distributor itself, I would install a WS system. If I could use most of the parts I already have (and I personally could reuse them from my car), I'd stick with the distributor setup to keep things simple.

Running vacuum tube into the car... you already have a vacuum tube running through the fire wall in your 2.3-16. Any problems with that so far?

regards,
Christian