Engine First Start

There is a bit of a check list before the engine starts up for the first time.
This is all about a LS3, Omex ECU and cable throttle with Jenvey throttle body. Probably similar for Canems but the software for mapping is will be different I would think.

First the essentials.
Fuel in tank and all fuel line connections tight. Especially check the connection onto the fuel rail.
Check all coolant hoses are tight.
Remove fuel pump relay if you want to spin the engine over with no plugs in.
Coolant. Advised to use OAT (pink/red) coolant. You will need at least 11.5 litres. It comes in ready mix or concentrate.
Oil. The engine has a shallower sump from original so a little oil may need to be drained out.
It came pre-filled with oil so I have left that in place.

By now I have all electrics connected and wired up. I couldn't be arsed to frig up a temporary dashboard, oil gauge and all bits necessary to start the engine way back before I had the body on. So where I am now is all connected as per final setup and ready to go.

Taking the plugs out is a pain, especially with a GEN III chassis. Lord knows how I'm going to get them out to change at first service. Anyway, spinning the engine over doesn't always get the oil pressure going enough to register. I really wanted to know the oil pressure is going to be there so I rigged up an oil gallery priming solution.

At the front nearside of the block is an allen key head plug. Remove it and insert a 16mm hose adaptor. Connect to this a drill driven pump (from Ebay, natch). Drain two litres of oil into a clean container, prime the pump, connect up, switch ign on. With drill running at full revs the oil light went out and I saw ~20psi pressure. So this has given confidence the gauge and light sensors are working, and also that we have an engine primed with oil from top to bottom without having to turn the engine over.

The 16mm dia threaded adaptor is at the end of the hose and screwed into the oil gallery at the front nearside of the engine.






Now we need a laptop running Windows (although I didn't check software is available for Linux, but well done if you have Linux anyway) and a piece of software called MAP4000 downloaded from Omex web site. A USB to serial cable is also required unless you have an ancient laptop and have serial ports. There is nothing special about the cable, don't spend loads on a special cable, just a standard USB to RS232 9-pin male is fine.

So, install software, open it and drop down the ECU tab at the top, choose connection setting. If a port doesn't appear you may need to install drivers for USB to RS232. Select the port.

Switch on ign but don't start engine.


On the setup screen are TPS settings. Make a note of the RAW setting on the left of the screen. Click on TPS min value and change it to whatever RAW was plus 2. In my case RAW was 9 so I set TPS min to 11

Now push the throttle pedal to fully open and note the new RAW number. Now set TPS max to RAW plus 2.



That's it. Now press the start button. The throttle may need to be opened a little to get it off a lumpy tick over. It will get hot and smoke and smell like mad. This is normal. But not if it goes on too long.

If it doesn't start then back to basics. Do we have a spark at the plugs, and does it come at the right time? Do we have compression? Do we have fuel entering the cylinders?

Take at least one plug out, lay it against the block to earth it and crank the engine. We should have a blueish spark. It won't be dramatic and hard to see in sunlight.

Stick a compression tester in the plug hole and crank the engine. A finger will do. If you can seal the hole against the pressure, there ain't enough of it.

Finally fuel. Are the plugs wet? At the front of the nearside fuel rail you'll find a shraeder valve. Depress it with a small screwdriver and crank it over and expect some air followed by spurts of fuel. Just like bleeding the radiators at home.

I ran it for about 1 min and then shutdown. Check all fuel, water and oil connections, joints etc. Check under the car for pools of fluid. I was lucky to have no leaks anywhere. Touch each of the exhaust ports to see they are all same temperature, means it was firing on all 8 cylinders.
I now went through the TPS settings again as the RAW figure changed slightly.
There is a small allen screw on the front of the throttle mechanism. It is spring loaded and sets the opening for the butterfly in idle position. Try to feel where it first starts to engage and then screw in another half to one turn. Reset TPS min and max if necessary (these settings are with engine off).

Now run the engine again and bring it to temperature. Check the temp on the screen and on your dash gauge. I found my dash gauge lagged behind the laptop display but got there eventually.
Omex ECU sets the fan to come on at 95 degrees. Check that happens and that air is flowing from outside in. If not reverse the fan connections.

Shut down and check oil, water and again all connections.

The fuel mapping can wait until the engine has run a few thousand miles to loosen up but there is one thing we can do now. At the bottom of the setup screen there are values for the Lambda sensor in the headers. F.B.1 & F.B.2. Ideally we want these as close to zero as possible. Anything above 10 and it will have trouble with passing emissions test, as well as running in a sub optimal fashion.

If it is high (mine was 30 which is the upper level of the possible display) it is running too rich, we need to adjust.
At  the top left of the screen is a tab called 'Standard'. Pull down the twiddle at the side and select 'mapping'


We now have this screen. With the engine running on idle, at the bottom there will be a square highlighted with black edging. If the FB1 & FB2 readings on the first page are high, click on the square where the black edging is and lower the setting. Mine started at 40 and I ended up with 18. But lower it in increments, it doesn't like big jumps.



If the difference between two adjacent squares are then too much, the black edge will hunt around between the two. The engine may also be hunting. So click into the next square and lower that as well. Mine started out at 40, I lowered it to 20. Keep going back to the setup page to check the F.B settings, they will hunt around a bit but should be in the range 8 - 11, or if possible lower.
After this you may want to again adjust the throttle idle opening with the allen screw, and then adjust again the TPS min (leave TPS max as it is).

The thing is that when adjusting one setting, it is often the case that that will in turn require an adjustment elsewhere where before it was ok. It is a matter of tuning the figures to get a nice tickover and a low F.B value.

That should do until it goes in to a proper engine tuning specialist who knows what he's doing after a few thousand miles.

Now would be a good time to check the clutch and transmission. Put something in the cockpit to sit on, put it in gear and check where the clutch bites. Mine was too quick from the floor so it will need some small adjustment. Check all gears select ok, as well as reverse. The lack of grinding noises is good.

I have actually videoed all this, but it is far too boring to put up for show.

Dashboard Wiring, Speedo and Rev counter setup.

The dash comes with pre marked locations for instruments which is fine but I did it slightly differently.

I like the important lights and gauges together so I can see them all with one look instead of having to scan the dashboard. Also, when I hit the starter button, I want oil pressure information in my line of sight. The clock isn't a gauge so it is separated out between the two big clocks. Finally I wanted the row of switches higher up so easier to see/reach. The start button has a quite lovely chrome finish base which I thought was a shame to hide so I mounted it proud of the dash surface.


AK will supply diagrams and explanation sheets along with the wiring loom.
The detail on these sheets is all you need to correctly wire up the rear of the dashboard as well as the steering column, wash/wipe relays and connections into the main loom. But there are some gotchas.


I was going to mount the wash/wipe relays behind the wiper motor, but it meant changes to the main loom. I think the AK desire is to mount it with the other relays on the passenger side so I have drilled and tap'ed into the scuttle hoop and mounted them underneath the main relay cluster. The two connections from the wash/wipe cluster connect into the main loom and into the wash/wipe stalk on the steering column. There is a separate connection from the main loom into the wiper motor. There is an earth strap from the main loom to connect to the motor bracket and I have earthed the steering column here as well

Dashboard connections are well represented by AK's diagrams. There are some wires the same colour, three red wires for instance. Fortunately they come from different connectors in the short loom for the dash so just buzz them through with your AVO and compare to the list in the wiring instructions. The only thing that tripped me up is the fact there is a wire coloured blue/red, and another one coloured red/blue. This was far too subtle for me and I got them mixed up until I went back to basics, buzzed them through and reconnected them correctly.

If you have the usual Smiths instruments tacho and speedo (mine from S&J Motors) there are two options to connect the sensor. Use the black/white connection in both cases.
The tacho sensor comes from the blue/yellow wire from the Omex unit. There is a wire in the engine bay leg for connection if you have a distributor, either use that or, as I did, feed the wire from the ECU and connect it to the pink wire in he loom or straight into the black/white on the tacho.


A proper ratchet type crimp tool is worthwhile. Mount it in a vice to free up a hand to hold the wire and terminal.







The terminals on the switches are very small. The correct size connector is often too small to get two or more wires crimped when daisy chaining. On some of them I stripped insulation part way along the wire and crimped the terminal there, leaving the wire to continue onto the next connection.

Multi-coloured birds nest! This is temporary to get everything connected, tested and later to start the engine. It will have to come out when the dashboard gets covered, but I'm not too fussed if it isn't perfectly laid out. It isn't on show and the important bit is the robustness of the connections. On the right is the voltage stabiliser. The screw mount is used as a collection point for all the earth wires. It needs to be mounted with the arrow facing up. Apparently it won't work properly if not. So if you find yourself upside down in a ditch, you may not be getting a correct fuel level reading.


I started with connecting all the earth terminals. Once they are identified it is easy to know the other terminals which aren't easily identified on their own. I have used heat shrink tubes over the connections. I hate pre-insulated coverings that squash and look horrible after being crimped. It takes longer but I prefer to have a good look at the crimp, make sure it is good before covering with the heat shrink and apply a hot air gun.


So, connect the battery, have the gorgeous love of my life standing by at the isolator switch with instructions should there be smoke and fireworks, turn the ignition and, lo-and-behold, it all works. Lights, indicators, wiper motor noises, quite a loud hooter. Brake, fog, reversing lights, all present and correct. Thank you Mr. AK.

There are two things. First the indicators work with the ign switch off. I reckon that is so the hazard lights work. And secondly, the hi beam flash on the indicator stalk works with the ign off. Weird, but correct according to how the loom is wired says the Man. I can't think why you would want to be able to flash your lights with the ign off. Unless you happen to be parked up in a country lane or car park late at night. And I have no idea at all why that would be.

As we may be fitting the rev counter now, there is some work to do with settings. I have the classic Smiths instruments from Caerbont Automotive. At the back of the rev counter is a round rubber bung. Behind that is a bank of switches. There should be a leaflet with the rev counter that explains how to set the switches according to how many cylinders your engine has and whether it is has a wasted spark system or not. The configuration for an 8 cyl engine with or without wasted spark didn't work for me, the rev counter was not reading correct RPM. It may be a 'feature' of the Omex ECU but the setting that worked is for a 4 cylinder single spark. That is to say SW1, SW2 and SW8 = on.

From the same company comes the speedo. It will need setting up to at least have a reasonable go at reading true road speed. There are regulations about how accurate it needs to be and you need to acquaint yourself with that. However there is a basic setup we can do before testing it on a rolling road.

This Smiths speedo has two methods. We can set it while static in the workshop, or drive it for exactly one mile and set it accordingly.

The manual method.

You need the circumference of the rear tyre and to know how many inches in one mile, the diff ratio and the number of pulses from your speedo sensor.

So we take divide 63,360 inches by the tyre circumference and multiply that by the diff ratio. That gives us the number of rotations per mile. Multiply that by the number of speedo pulses per revolution and we get a number we can use to set the speedo.

So in my case:

63,360 / 80 = 792

792 x 3.54 = 2803.68

2803.68 x 12 = 33644

33644 then is the number to use on the speedo setup.

There should be a leaflet that describes how to set the speedo but basically hold the trip reset button in and switch on the ignition. Release it before the needle does a full sweep and it will enter setup mode. Set the number by pressing the button to increment each number, then switch ignition off.

That should do until we get it on a rolling road and see how it worked out.

By the way, if you find the trip button not working properly, it will most likely be because the good people at Caerbont have soldered wires to two thin terminals at the back of the button but then left them bare inside a heat shrink covering. If the terminals get bent during installation, and they probably will, they end up shorting out. I had to cut the heat shrink away and then properly insulate the two terminals from each other.

Steering column, throttle cable, dash cutout

The requirement is for a BMW E34 steering column along with the lower steering shaft.
There are a couple of dudes on Ebay who know just what you want - for a price.

The steering column needs to have the left side mounting arm cut off and a portion of the top plate.
The ignition lock needs to come out. Try to get a key with it. The ignition switch barrel needs to be turned to a certain position with the key. Then insert a 1mm dia something into a small hole on the edge of where the key goes in. This release a catch and the barrel slides out. I didn't have a key so I had to drill it out. Ideally remove the steering lock mechanism as well. There should be a small steel pin driven into the cast ally which bisects the hole the long arm of the lock is in. Punch or drill it out and then remove the steering lock arm.
Remove the indicator and wash/wipe stalks for later use.
We should now have something like this:



There seem to be different lower shafts. I had the wrong one originally, the section without splines was too short.

So the bearing collar from AK will not fit against the wall of the footwell.
The Ebay guy sorted it out and sent a different one which had longer overall length.


I had to mount it with the shaft bush slightly over towards the engine. The steering shaft down to the rack only just passes the upper suspension mount, moving the bush over a short way gives it more clearance.
And talking of clearance, you probably got a big nut with the steering column that tightens the upper shaft onto the splined lower shaft. Unless you have a wider footwell than everyone else, it won't fit. Leave it off. The nice man at AK swears you don't need it.











When the steering column is fitted, make sure it is properly earthed. The mounts are plastic and rubber, it needs a path to earth for the hooter if nothing else. I connected an earth strap down to the wiper motor bracket.
The dashboard needs to be cut around the upper plastic shroud. AK have etched a line for this. I measured it and the line seemed fairly accurate. I cut inside it, test fitted and only had to open it up a small amount. The finished thing has about a 5-8 mm gap.





You will need a hub and a (possibly temporary for IVA) steering wheel. AK has some suggestions in the manual. I spoke to Merlin and ordered a BMW boss, IVA compliant, and a cheap steering wheel, which actually looks not too bad.








Throttle Cable
While having ones head down in the footwell, I connected up the throttle cable.
And wished I had done it before the body went on at the same time as fitting the pedal box.
The cable from AK has a threaded end with two nuts to secure either side of the footwell wall.
Thing is that the threaded section is too short to give a good length for nuts and washers on both sides of the wall. The solution, then, has a close fit washer on the engine bay side and a single washer/nut on the inside. I had a 5mm repair washer, used the conical drill to open it exactly to 6mm. It is then a close fit over the thread. The cable has an edge on the outer cable sheath which then buts up nicely against the washer. Don't try to fit it with neither nut or washer, it will eventually pull through the wall.


Fitting the nut and washer on the inside was nigh on impossible. I managed it but I so wish I had done this before the pedal box went in. Make sure the throttle arm lines up exactly with the cable as it protrudes into the footwell. We don't want the throttle pedal pulling the cable out at an angle.
The other end of the cable has a nipple with a tiny grub screw to secure it. And it doesn't fit the Jenvey throttle mechanism as one would like.

For the cable to pass completely through the nipple, it needs to be able to pass through the centre of the hole











The thing is that you don't want to have to put the screw tightened nipple right at the end of the cable. We need to be able to secure it past the nipple and also to have it as an extra adjustment. I spoke with the guy at Jenvey and he confirmed it is the way it is. He thought we should have a permanent fixed ball end - as it is at the pedal end - to slot into the mechanism. All it needs is for the cable slot in the mechanism to be bored out past the hole where the nipple fits.

Now we can fit the cable properly, adjust it, cut it to a sensible length and secure it past the nipple.