megasquirt write-up for w201 - bounty

[The Benz Master]

chrisfball12, i relly dont know, i still have a few details to get right like the airbox support bracket and give the hell of a good cleaning in the negine bay. but right now i live prety far from my garage so it's not very practical do to some fab work in an appartment.

I'm also making customlenghtened camber arms for the rear and some tuning, etc... so i belive it wont be before winter (unless i get a week of vacation before that but unfortunately, i dont think this could happen.)


that's interesting Hexadeca... in my case, the MS2 is driving a MSD-6 so i would have no problems at all connecting it directly to the tach.

the second part just reminds me some things i've read on the MS forums about people adding some capacitors and things like that to the line to the tach to reduce noise/voltage spikes ( i think a MOV might be perfect for this task)


P.S. if anyone has a manual on hand, i belive they show what you should get when you scope some signal wires.. this could give us our answer.

[Meshuganah]

Hello guys, I'm a newby.
Read through your posts so far and have descided to do the conversion too.
I have a 2.0 l 8valve job which is giving serious problems in the fuel distributor dept and spares for this old model are too expensive.
So....I have looked at the megasquirt site and its cool by me.
I wonder if a 36 tooth bicycle gear, the front one, will do for a pick up. (Maybe from a BMX?)
I can get my hands on a ford throttle body too. Should be the same over here, although we have the 'Falcon' range. I hear they have really big throttle bodies..
I will post photos if you would like, but do you have this engine in the U.K., Canada, U.S. etc?
I hope to keep the ignition part as standard, but maybe I should go the whole hog.....any advice?
Cheers, Meshuganah

[The Benz Master]

on my part, i did the full swap and it worked ok... had one or 2 issues concerning ignition but nothing complicated. A fuel only swap might be a little bit easyer but not that much... I'd say start with the fuel management and do the ignition one or 2 months after, once fuel is set properly and working fine == so you wont have to troubleshoot 4 problems at the time when you have some.

we never had the 2.0 in canada but it seems as it's very similar to the 2.3

for the trigger wheel, i'd sugest buying it from me (you got PM).... cheap and very reliable (hall sensor). It saves the hassle of trying to eliminate noise and fidling with the pots on the MS board to get signal. It's quite hard to diagnose a VR sensor without a scope too. On the other hand, a hall sensor is a lot easyer with the 5v square wave output.

[Meshuganah]

Hi, Even easier. For a start I will take the trigger of the coil/tacho and get the whole thing up and running.
Then as you say, get the wheel and start upgrades till it is optimal.
That allows me to get any problems sorted as I go along.
I have removed the manifold and will drill it today and fit the injectors.
I am making up the fuel rail with rubber hose and brass t'pieces with clamps.
I will keep the original cold start and fit a t'piece for that too.
My 8valve is the same as the 16valve....same block, different pistons or stroke though. Seems like the head gasket is the same.
These engines look like they can breath well so, good for some extra grunt!
Cheers.

I am sure you guys will be able to help out if I get stuck.....Here goes!

[The Benz Master]

not sure about the oem signal to drive megasquirt...you'll have to scope it to know if you can use it or not. you either need a 0-5v square wave signal or an AC voltage that crosses the zero volt mark at some point.

I think what you refer as a cold start valve is in fact the idle air valve. If it is what you are refering to, you cant use these models of valves with megasquirt... you need to adapt a fast idle solenoid or a 4 pin IAC from almost any GM since 1990.

If you are refering to the other thing that looks like an injector, well, just ditch it cuz megasquirt will automaticaly compensate fuel with the temperature sensors, so it's not needed... the art of fuel injection my friend, some stuf can just be thrown away

[Meshuganah]

Wow, Thanks, I didn't know that yet.
So the extra 'cold start valve' that works for 8secs when cold through the extra injector is now redundant...... Cool. More space for other stuff.
I drilled the ports Today. 10mm for the through holes and 16mm all the way down to the step.
Assembled the injectors and put together the fuel rail.
I think I can use the original fuel regulator and fit a pressure gauge to the extra (small) outlet. (Just to block it off.) The vent will go to the inlet manifold somewhere...
Thank goodness I dont have to pipe in that other injector.
Looking for a GM 4pin IAC....
I will put up some photos when my camera batteries are charged.

Cheers.

[Shisamo]

We cant use the idle air control valve that from the car ? I think we can use it , isnt it ? I read the MS manual it say 2 wire or 4 wire both work fine ...but may be im wrong ....Im planning don't use IACV , instead use that fuction to control the electric fan ....hope it will work ...but what im worry is the cold start problem

[Meshuganah]

I am using the same auxilliary air by pass valve, the one that sits in between the runners...its a two wire but is good. Also pressure regulator can stay.
Don't need the cold start valve because the computer will put extra fuel when cold starting.
I am waiting for more brass t'peices so that I can finish the fuel rail and I will put up some pics.
The throttle body has to have a position sensor and I will post that too.
Then it is build and install........
Cheers

[The Benz Master]

i think most 190e's have a 3 wire idle air valve!? if it's two wires, i guess you could make it work.

indeed, when the engine is cold, it's harder to get it started without a idle control valve. You have to step on the gas a few minutes to prevent from stalling.

i do use the "fast-idle" port on the megasquirt to control the fan and it works fine... that's also one of the reason why i'm going to a GM 4 pin IAC... it connects elsewhere on megasquirt.

[The Benz Master]

P.s. for pressure regulator, it depends on the car, the 2.3-16 has a very high gas pressure compared to the others so you cant use it unless you want/need big injector flow.

[Meshuganah]

Thats interesting.
I am not sure if we need to go that high though, because the injectors on the new system are periodically opened, not always open .......still at 14.7:1, you still need 'x' no of units..

I am looking for a TPS. GM is too bulky ($80.00 too) for the space allowed but the Mitsubishi Lancer looks good.......nice and flat. But on the opposite side of the TB!

The differences that occur are that some units attach to opposite sides of the throttle bodies depending on which car they are from. Thus they move anti clockwise or visa-versa to do the job. Mitsubishi works on the outside 'left hand side' of the throttle body, whereas, the 190E shaft comes out on the inside 'right hand side' of the throttle body.

Just exchange the +5v and 0v leads over, so that it will read backwards. Because they are linear, it makes no difference to the output.
0v will still be at idle and +5v will still be at WOT. Turning it upside down won't help.

Cheers

[The Benz Master]

ehh... just use parts from the junkyard/dismantler.... you'll pay like 20$ for a complete chevy cavalier or honda civic intake manifold with throttle body and all the sensors, iac, etc.

i think the 2.3-16 had like 80 PSI of fuel pressure.... i'm not sure tho. Normal cars are at +- 43 psi. std 190e were at 60-65 if i remember well.

[Shisamo]

But i saw many people have problem when using idle port to control the electric and use the GM 4 pin IAC in the same time ...somthing look like only if the fan work the IAC wont work. if the IAC work the fan wont working correctly ....somthing like that....

[cypres]

what if it is the 190, but different motor? I thought it was going to be hopeless trying to wire this thing, but knowing that it would have been just as hard with the 2.3 makes me feel better.