New member - Excel SA

[Excel SA]

I've been neck deep in wiring and wiring diagrams to get the engine and gearbox wiring to something closer to what I think is acceptable.....the vast majority of Lexus V8 conversions done in South Africa are for 4x4 type vehicles I think, and maybe the work done to get the engine working is based around that and perhaps somewhat crude....

Below is a picture of the wiring that was added to get the engine running - I believe work also needs to be done to bypass key/security features, as well as removing any unnecessary wires. There were a number of things I didn't like in this little bundle.....the use of the pre-insulated connectors - something about these things bothers me a lot! If you look at the fuse box, you can see that the crimping was poorly done, and wires have already escaped from their connectors - not a good thing. The power into the fuses and relays also pretty much daisy-chains its way through these connectors which may result in more current than necessary going through any particular connector. There are 6 x 30 Amp fuses - as mentioned in an earlier post - some of these are there as fuses, some are essentially just connection points. The wiring used was all 10 or 12 gauge wiring - mostly in lengths too long for my needs, and unnecessary when it is connected directly to an 18 gauge wire from the ECU. All connectors were also soldered to the pins they were connected to - not so useful when you have to replace a relay one day.



I ordered a combined relay and fuse box as per the pic below - the one I ordered didn't come with relays and fuses - just the plastic housing and the necessary pins. It's not the highest quality item in the world, but should be a lot better than what I had. It was bought off a site I was a bit concerned about if I have to be honest! I also bought a few other items that were needed and were well priced - I was pleased (and a bit surprised ) to receive everything, nicely shipped from China. Other bits ordered were a decent bluetooth OBD reader, LED bulbs - for the rear lights and a few interior ones



Much work was done to trace and note all the various wires that needed to be removed, as well as checking the Toyota wiring diagram to better understand how it was supposed to be done. The Toyota wiring diagram showed a number of extra fuses between the relays and the ECU, and figuring that the clever chaps who designed the system knew best, I (hopefully) incorporated those into my wiring. Six fuses were needed for this, so I have used the 6 that were in the box with the relays, and will use the originally supplied fuse box to supply power to the relays (Ignition, EFI and start) and anything else I need to power.

Below is the start of re-doing the wiring - I have tried to use the same or similar coloured wires (I have the remains of the wiring harness from the Toyota the engine for my 7 came out of) to extend the wiring where necessary. The idea is to fit the ECU, relays, fuses etc. in the passenger footwell, behind the blower/fan. All replaceable items will need to face downwards for access - I will need to reinstall some of the interior to work out where all those bundles of wire can actually run....The bracket to hold the ECU etc. is a temporary mock-up for now that can be chopped and moved as necessary.



So far I have made all the connections necessary in the fuse/relay box but haven't joined all the wires together that need joining - I need to confirm exactly where they will run before cutting them to length - I also invested in a packet full of heat-shrink tubing and loom covering tubing.

I have been keeping a fairly detailed wiring diagram to keep track of what I am changing - nonetheless I have a great fear of not being able to find a stray wire somewhere along the line.....


Neil.

[Pete Boole]

Great work Neil. When I used the Chevy ECU for the Excel I had to build a 55Hz square-wave generator to fool it into thinking the original key was in use - what security is your ECU expecting to see? I also hate pre-insulated terminals - don't like the look of them or the security of the crimps.

When do you think the engine will get fired up??

Pete

[Excel SA]

Hi Pete,

I've got one of those generator type things to fool my ecu into thinking the car's going at a different speed to what it is! There should be no security issues as it stands - part of the deal is that you get a running engine with just fairly basic connections made.

If I gave you a date I will have it running I'd be lying, and probably a long way out!

Neil.

[MetBlue]

I've got one of those generator type things to fool my ecu into thinking the car's going at a different speed to what it is!

Does it work with Speed cameras?

Tony

[Excel SA]

I've got one of those generator type things to fool my ecu into thinking the car's going at a different speed to what it is!

Does it work with Speed cameras?

Tony

Time will tell! Haven't received a fine in the post for years......sending anything through our postal system is never a good idea!

Neil.

[Excel SA]

A bit of a delayed update, but have had a few other chores to do and some foul weather to deal with the last few weekends - rain and now it's cooled down to below uncomfortable.

I replaced my wife's Merc C320 CDI that was starting to give me more chores to do than I could cope with - at 348 000 kms it had done well and the engine was stilling going like a dream! Replaced it with another Merc (not new) and have had to do some fettling to get it in good order - automatic gearbox oil change and a coolant flush - well there was only water in there so not really correct - it has coolant now, and a new expansion tank....why not just put coolant in it? Mind you the sump plug leaks a bit and the cure for that is apparently blue silicone around the sump plug - great mechanic who serviced the car......It seems to be a nice car otherwise!

It has just been more wiring - thankfully I've done the vast majority of what I can do for now.

The original wiring was in a pretty bad state in some areas - it was damaged, hacked into, over heated and generally a bit bodged. I've gone through everything, re-wired and repaired where necessary including replacing fuses and fuse fittings to get it as close to the way it should be as I can.

None of the engine wiring that went through the firewall to the engine needed to go there anymore - where necessary it was re-routed to the Lexus ECU - start, ignition power, A/C etc. while other wires were connected or re-run where necessary - oil pressure and water temperature senders, tacho signal, alternator warning light and reverse. Any wires not required were de-pinned and removed.

In some cases I could re-use existing wiring and signals - the SA has a feed from the brake pedal to the gear lever that continues on to the cruise control - the circuit is complete when the gear lever is in D I think.....this wiring was re-purposed to release the Lexus gear lever to move it out of Park - better than pushing the button manually, better to get it working as it should.

As mentioned earlier, I rewired all the fuses and relays on the Lexus drivetrain as I wasn't happy with the way it had been done - wiring and fuses are now pretty much in line with the Lexus wiring diagram and all the battery power running to the various relays is split from a spliced bundle rather than all running through a string of badly crimped connectors. There is also better colour coding of the wires. I am hoping I was careful enough not to cock-up any of this wiring - trying to trace any issues will be tricky

There was no radio in the car, the radio wiring had also been chopped a bit, the plug for the new radio has been wired in permanently - if I remember correctly an extra wire was required to let the radio know when the car lights were on.

I have added in an OBD II port - the CAN Bus wiring was there from the ECU so it has been used and run to the OBD connector as well as to the new speedometer - and hopefully properly terminated....twisted wires and 120 Ohm resistors are apparently required - the speedo has one of the termination resistors built-in and I added in another at the OBD connector- my understanding of all this is limited! I have also bought a Bluetooth OBD reader that can be left plugged into the car permanently if required - it does shut down completely after a while according to the documentation.

The speedometer has been wired in - there are two plugs on the speedo - an 8 pin and a 12 pin plug - 20 wires for a speedometer.....6 of the 8-pin wires have been used - earth, power, ignition, lights, CAN High and CAN Low - the other 2 may be required if I can't fool the engine ECU with an adjusted speed signal. I am waiting for my son to get home from college in the US in a month or so - he has the required bits to modify the speed signal from the gearbox to the ECU - if it works, the speed signal will be sent over the CAN Bus to the speedo, if not, I can send the signal directly to the speedo from the speedo corrector - I have put in spare wiring for this. Only 3 of the 20 pin plug wires are used - CAN H and CAN L, and I have fed the warning light from the Lexus oil pressure warning switch to the speedo on the 3rd wire - a red warning triangle will light up if warranted.

I have also added in a combined remote lock/unlock and alarm system - another 13 wires to connect! Once again I have tried to add the wiring in properly, and not simply hacking into wires running past the system! The lock/unlock signal wires were already damaged where they went through the driver's door, so I have spliced the units wires at the same damaged spot that needed to be repaired and heat shrunk anyway. Almost all this wiring is now connected - a few earths need to be added, and I will have to wait to connect the lock/unlock wires as I don't know which one is which .

All the above has resulted in a huge pile of wiring - the original loom inside the car is pretty convoluted, now it is even more so. I am trying to run as much of the Lexus wiring in the car as well - there is very little space in the engine bay to run wiring across the back of the engine, also to try and keep the engine bay fairly neat and clean - I'll have to get most of the dash components back in to see just where I can do this.

The next plan - hopefully over the Easter weekend - is to get the engine and gearbox back in so I can make any necessary changes to the body work to get clearance, as well as to work out where all the additional bits can fit - remote oil filter, air intake piping and filters, air-con piping, coolant piping, power steering reservoir, washer bottle, fuse/relay box for the fan wiring etc. - crikey that's a long list of stuff to still cram in there!

Sorry there are no pics - they would be of no use anyway - just of a spaghetti bowl of wiring!

OK - 1 pic - this is how I've tried to keep track of what wiring has been done It does mean something to me!




Neil.

[Alan_M]

Sounds like your wife’s Merc still had loads of miles left in it My E320cdi is currently on 485,000km and that’s going up 7,0000km a month.

I feel your pain with the wiring - just fitted a tow bar to my Merc on the weekend and that was enough wiring to contend with.

[Pete Boole]

Excellent work on the wiring Neil! It does seem to go on forever sometimes! I'm going to cheat to some degree when I buy my ECU and buy a "pigtail" loom to go with it

Looking forward to seeing photos of the engine in place!

Pete

[Excel SA]

Those Merc engines seem to go on for forever - once you've changed the oil cooler seal anyway - not a job I ever want to do again! If the rest of the car hadn't started falling apart.....changed it for a C220 CDI Estate - the estate is much more practical for work - you can get a 3m long length of floor trim in the car!

Ha, I thought I was saving myself time by getting the Lexus ECU all pre-wired - only 6 or 7 wires to connect up to get it running they said. Which was probably true, until one of the poorly crimped wires fell out.

Haven't I posted any pics of the engine in yet? It has been in a few times already. There's a very slight ramp into my garage - easy enough to haul the chassis and body in and out of the garage as required - not sure it will be so easy, or even possible, with the added weight of the engine and gearbox in there.

Neil.

[Pete Boole]

I bolted a small hand-operated winch at the back of my garage for exactly the same reason! Anything to save my back

And there is a picture of the engine bay on page 26 of this thread! Sorry - not paying attention . More would be good though!

Pete

[Excel SA]

I think I have a small boat trailer winch stashed away in a box somewhere - that may have to be hauled out.

Some "engine in" pics for all - these were taken a while back - if you look closely you can see the standard of old "sanding" on the wheel arches - done delicately with a large angle grinder it seems.

From above - no, that's not a giant roll of loo paper - it's a workshop roll which was used to see if there was space for an air filter - I just don't like the idea of an air intake in a hot engine bay though - an air filter in the nose cone above the radiator ducting would be ideal....



From the passenger side - space is very tight at the rear of the engine - there is no plenum intake/drain fitted in this picture, and the plenum will almost certainly require some changes. The feed to the heater radiator will also be interesting - the Lexus one points straight up and is above the Excel one pointing straight down...



From the driver's side - plenum in place this time, no real space for wiring and piping at the back - the Lexus heater pipes do go over the engine, but I'd rather not have that look - and there won't be a plastic engine cover to hide it all.....The engine cannot move forward or backwards more than a mm or two - the front cross member is too close to the sump in the front, and the rear of the gearbox is too close to the chassis at the back. It fits in this position, and this position only. The vacuum hose to the brake booster works out well.



From the side - minimal clearance to the underside of the bonnet - not enough space for an engine cover!



The engine bay will be full when I'm finished

Neil

[Pete Boole]

Thanks Neil - lovely to see the engine in there! Going to be great when finished

Pete

[Lotus-e-Clan]

Engine still well back behind the front axle!

Should offset much of mass differences.

[Excel SA]

It's as far back as it can go without cutting into the firewall! The gearbox is also slung back far and low and filling the transmission tunnel.

I've also lost a few kilos of body filler, fiberglass patches and badly welded on plates

Below is a pic of the engine wiring loom fuses and relays as provided with the engine:



And now - redone with a proper relay box and extra fuses. There are covers for the top and bottom of the relay/fuse box. Some spacing and clearance issues on the ECU cover for mounting the components, should be good when final bracket is made.



Making an extra few earth leads - after soldering on the top half of the picture, after heat shrinking below that.



4 day weekend coming up, but a lot of rain predicted from Saturday to Monday....you'd think I lived in the UK

Neil.

[Pete Boole]

Looks sooooo much better than what you were supplied with. I can see you're a dab hand with a soldering iron as well

What we need next is a sound clip of the V8 running! . Does the Toyota engine have the traditional V8 burble or does it have a different firing order (like the LS series)?

Pete