pinout questions

[richard s]

i have been advised that for a neater install and a better understanding of the wiring to the ecu that i build my own loom but need help with econoseal plugs
i am using a 4cylinder engine that is going to be converted from k/jet to efi
are the fuel injectors on pins 7/8/19/20
also what are the ignition outputs for on pins 10/11/12/24/33/34/35/36
cheers

[Jorgen]

Hi,

The questions you ask is a bit basic, have you read the installation guide found here: http://www.vems.hu/wiki/index.php?page=MembersPage%2FPhatBob%2FUserGuide

It is in no way simple to install an engine management system the first time and if a question like that comes up after reading the manual you may want to talk to a VEMS installer about doing the install. Where are you located?

At the very least you should buy from a certified and experienced VEMS reseller that can give you proper support for the product. Those who buy from the www.vems.hu webshop should primarily use the www.vems.hu Wiki for support.

The 2.3-16 Cosworth Mercedes is also one of the hardest engines to convert, on most engines you can use most of the components but on the Mercedes Cosworth engines you can't use a single component. We have done a large number of installs on these cars here in Gothenburg and we have developed some good solutions.

Jörgen Karlsson
Gothenburg, Sweden.

[richard s]

hi jorgen thanks for the reply
i have not read the installation guide as i dont realy get much time on my pc so when i look at the wiki it is realy a quick look but then again i dont look at the members page
i have been on the mercedes 190 forum and this is where i learned about the efi conversion and to be honest it is the wiring and configuration part of the conversion that i am most unsue of
outside of wiring up a couple of alarms and doing the odd wiring repair i have not done any serious wiring this is why i post questions that may seem simple but i am at the learning stage
i am located in sheffield in the uk
thanks again for the link to the user guide and if there is anything else that you can think of that would help me get a better understanding  i would appreciate it
cheers

[richard s]

could you tell me if i have the basic jist of it
for tps switch i would need to use pin1 for letting ecu know how open throttle is
pin28 for live feed to switch
and a earth
for injectors pins 7 8 19 20 and flyback lead with diode and a earth
this is not a list of switches etc it is all i can remember without having the pin out diagram in front of me
all its for is for you to tell me if am heading in the right direction
cheers

[rob@vems.co.uk]

could you tell me if i have the basic jist of it for tps switch i would need to use pin1 for letting ecu know how open throttle is
pin28 for live feed to switch and a earth

Thats about right, the +5V from pin 28 is okay, but we have a TPS specific output on pin29, either will do if you're not looking to power much with the main +5V supply.  The feed to pin1 tells the ECU the position of the throttle, part of the configuration of the system is setting the open and closed limits of the throttle.  And the third pin of the TPS goes to the ground cluster 10-15cm from the VEMS.

for injectors pins 7 8 19 20 and flyback lead with diode and a earth this is not a list of switches etc it is all i can remember without having the pin out diagram in front of me
all its for is for you to tell me if am heading in the right direction

The key to remember with VEMS, and almost all other ECUs is that they switch a live feed to ground - so the injectors are fed +12v, but until VEMS closes the circuit the current cant flow, so the injectors do not activate.  This is why we have so many grounds and why they must be connected up in the prescribed manner as a lot of high current devices (injectors, ignition coils, and other solenoids) can be grounding at any time.
The flyback lead from pin23 will have a connected internal to the ECU - if you get a recent box.  The trouble with the UserGuide is that some of the information changes, but you have to cater for the earlier ECUs too!

Cheers

Rob

[Jorgen]

Hi,

You got the part with the TPS right except for one thing. You talk about earth as if it some almighty constant that can never cause a problem. It is however what cause most problems!

So the ground signal to the sensor needs to be wired exactly like in the user guide, any other way and you will have problems with the signal quality...or worse.

I made a post on our Swedish support forum about the grounding, I doubt that the text will be of much help for you but it shows the steps involved in making the ground loom. I always do the ground loom this way (well, not usually with wires out of the junk bin...): http://www.vems.se/forum/viewtopic.php?t=460. I only post it here to show the attention to detail needed for the ground.

The injector pins are right but you need to read up a bit. The injectors in a car is controlled on the negative side. This means that they are fed 12v when the ignition key is on and that they are grounded by the ECU when we want them to open. This is also true for most relays in a car application.

You really have to take the time to read the user guide carefully at least two times, if you try to cut corners the install WILL fail. When I read documentation I usually read it from top to bottom once while marking the problematic areas, I then read it again concentrating on the hard parts. On top of that I use it as a reference when doing the actual work.

Jörgen

[rob@vems.co.uk]

Thats reminded me, I did somethign similar myself:

[BenFenner]

Same here... Sorry for the large pics.

[richard s]

thanks for the replys guys
i am all for reading something until it is better understood but the other dayi tried to copy the user guide to notepad so i could print it out but when it went on it had text but no diagrams so i could not print it out
rob/jorgen
are the pictures regarding where the earths meet then go into 6mm wire. so is it two different styles with the same end result
also does anyone know how to copy to notepad with images and text so i can print user guide without losing the last few words of every sentence

[richard s]

ben u must be mad using just one colour wire what hapens if you lose one of your masking tape labels

[rob@vems.co.uk]

rob/jorgen
are the pictures regarding where the earths meet then go into 6mm wire. so is it two different styles with the same end result
also does anyone know how to copy to notepad with images and text so i can print user guide without losing the last few words of every sentence

This is quick and dirty - so its rough looking formatting:
Right click and download this or it might take a while to get it to show:
http://www.vems.co.uk/VEMSSchematics/VEMSUserGuide.pdf

[richard s]

cheers for that rob but as sods law dictates i ran out of paper half way through printing

[BenFenner]

ben u must be mad using just one colour wire what hapens if you lose one of your masking tape labels

Hey! That is high dollar stage striking tape. =P

I guess I'd just trace the wire and look at pin-outs to see which it is. I never had that problem, and now it's all stuffed by my firewall never (well almost never) to be seen again.

[rob@vems.co.uk]

cheers for that rob but as sods law dictates i ran out of paper half way through printing

LOL!  I get a feeling that your installation may be a little eventful!

[richard s]

just finished printing it off all 69 pages and at first i thought it would work because this time my adobe reader kept trying to take over then tell me it could not find file and when i shut adobe down the link was a blank page but after i swore at it a few times the link opened first and then i started from where i left off
i just need to number the pages punch some holes in it find a ring binder and then read it
(living life on the edge or what)