This car is an ECE 190E 2.3-16v, therefore it came without an emission system or oxygen sensor. The stock CIS fuel injection system completely failed. Excessive fuel wash and the destruction of multiple catalytic converters lead to the decision to go with a stand alone set up, rather than pain over the antiquated CIS set up.
The project initially started out as an attempt to see how simply a stand alone could be set up. The engine ran ok after this half-assed attempt, but the drive-ability was piss poor. Idle sucked (no IACV), tip in sucked (half assed tps)... Eventually this was all replaced/fixed but I would highly recommend skipping the half assed attempt.
The Engine:
2.3-16v. 2.3 liter 4 cyl 16v engine from 1985. Stock it made 185hp. The head was designed by cosworth, the rest of the engine was very similar to the normal 2.3-8v.
The Parts:
Assembled VEMS v3.3 with 90% assembled wiring harness
Sensors:
MAT sensor: sold on Vems shop: http://shop.vems.hu/catalog/sensor-p-115.html
Coolant Sensor: Stock Mercedes - Needs replacement/calibration is incorrect based on OEM resistance curve
Motec TPS
Crank Position Sensor: CherryCorp GS100502
Fuel
Bosch 330cc injectors: http://www.fiveomotorsport.com/domestic-high-performance-fuel-injectors/?itemid=1277
SAAB 900 fuel rail: Same cyl spacing as the merc 102
Mallory 4305M adjustable fuel pressure regulator - run at 3bar
Ignition:
Ford Motorspot EDIS coil pack. Still direct fire from the VEMS ECU (no EDIS controller). Had a bit of a mishap and melted my bocsh coil pack from the vemsshop. The edis coil packs can be had in the junk yard for a couple bucks, so I went with one of those. The electrical requirements are nearly identical to the bosch one. Different physical connections, but thats about all.
Plugs: bosch H8DC
Wires: Custom set from Magncore. Actually very nice wires and were very reasonably priced. Ordered with EDIS coil ends.
Pictures of build
Intake Manifold
Here are some pictures of the CIS injector to EV1 injector adapter.
Overall picture of the fuel rail, fpr and busted PCV hose
TPS
The TPS was a particular pain because of how close the throttle body is the to intake manifold. The TB could have been rotated, but this would have required modifications to the throttle linkage, which seemed harder.
The solution is to machine down the boss for the stock idle/wot switch, weld a glob on the end of the shaft and grind it down to fit whatever TPS sensor you choose.
IACV
The stock IACV was routed from the bottom of the MAF housing to a port on each injector. The modern injectors would not support this type of routing. I had already decided to keep the MAF housing (completely gutted) in order to use the stock throttle linkages, so the IACV port was still accessible.
It happened that simply turning the stock hose that lead to the cold start valve (which lead to each injector port) upside down would put it right between runners 2 and 3 in the in the plenum. Had a hole drilled and attached a bung. Problem solved.
The Valve itself is a bosch 3 wire, stock in 1985. Diodes were attached to the connector.
Trigger
The initial trigger wheel used a thin wheel and a vain type hall effect sensor. The clearance was very tight due to poor machining. Eventually the aluminum bracket for the sensor warped with heat cycling and probably an over torqued bolt.
Disliking that system, I decided to design my own trigger set up that used a more OEM like sensor. The wheel is screwed into the stiff side of the skimmed, to make up for the width of the wheel, harmonic balancer. It was screwed in axially, not radially, to ensure a solid long term hold.
The sensor was picked to fit in the OEM location, which had a smaller than normal diameter. It wasn't until after I had a small supply of these sensors that I decided to move the location for ease of install, repair.... So it is not a typical automotive sensor style, but the sensor inside is identical to automotive grade sensors.
Sensor in pic was a test, final version is the whole sensor with proper shielding and protection.
Jim