Exige Motorsport S1 Honda With Jackson Supercharger - Engine Fuel Pump

[SCOTTJ]

Hi,

 

I've purchased a 1999 S1 Exige Motorsport which has a Honda K20A and Jackson Supercharger installed. During the winter months i'm tidying up the fuel & wiring installation ready for 2013 or to sell on once tidy. I've renewed all the fuel pipes and now it is time for the electics to be overhalled.

 

The base Exige S1 has four separate relays in the engine bay rather than the MFRU box found in my S2. I purchased manuals for Elise S1 off eBay but non of the wiring diagrams have separate relays for start relays, fuel pump, main relay and O2 sensor (Possibly). Does anyone have wiring diagram / colour codes for elise with separate relays? I am usure why it has separate relays?

 

I need to re-wire swirl pot and additional fuel pumps as they are poorly wired. Currenty they have a separate relay and wires energised from the ignition and are on constantly when you turn the ignition to position 2 (Prior to cranking engine)

 

1) Does anyone have a wiring diagram/harness colour codes for Elise with 4 separage engine relays?

 

2) Will it be possible to wire fuel pumps to just prime and presurise fuel rail or will they need to be running all time from position 2 of ignition? Currently the inertial switch & cobra immobliser are not in the circuit and ideally i want to get these wired in so in the event of a bump fuel is cut off.

 

I have tried to map the wiring harness colours for the two Engine Harness Connectors but they don't seem to match what colours are detailed in the Lotus Service Notes.

 

Any help would be appreciated.

 

Thank you

 

Scott

[Martin R]

Scott, nice buy Is it a genuine S1 Exige motorsport car? If it is i expect its wired as a special by Lotus Motorsport origonally. The other complication being it would have had a VHPD in it to start with.

 

The only thing i can suggest is get in touch with Roland Leftly at Lotus Motorsport to see if he can supply you with the origonal wiring diagram? It will have been heavily modified to fit the Honda though.

 

 

Edit, could we have some pics please?

[SCOTTJ]

Hi Martin,

 

Good to hear from you, long time!

 

I know very little about the car it was registered in 1999 and the VIN plate indicates it is an Exige but nothing about the wiring loom (Which has only been soldered into recently when the supercharger, swirl pot and extra fuel pump were found to be required) indicates it is a production version (It is like the multi-function relay unit did not exist)

 

I know very little about the Exige Motorsport S1 setup, but what i can say is the bulk head behind the seats seems to have been extended with a box section into the passenger area behind the seats, overlapping the top of the fuel tank. Ideally i wanted to pick up the standard wires to the fuel tank and plumb new fuel pump and swirl pot into standard loom but i dont seem to be able to get to access panel for standard fuel behind passenger seat. The Jackson Supercharger and Honda power plant go nowhere near the fire wall so the bulkhead was not changed for this. Perhaps was VHPD with exhaust 4-2-1 that required this?

 

It is an extreemly fast car, it makes my S2 Sport 190 feel like a ford KA in performance terms i just want to know before i use the powe fuel and electrics are better.

 

I've not got Rollands contact details, i've got Russell Gibbs and he's helped me out a coulpe of times. I'll drop him an email seee if he is still there.

 

Any other thought would be greatly appreciated.

 

Cheers

[SCOTTJ]

Couple of images... I'm still not sure if it is too track focused for me as it is extreeemly fast so I may well sell

 

 

I will take picture of 4 relays tonight and post...

[Martin R]

Scott, Roland Leftly ( Lotus Motorsport ) 01953 608920 There is also a chap at Lotus who if you give him the VIN number will tell you the build history of the car. Found it, his name is Andy Graham 01603 732178 [email protected] Hopefully its still the same.

[SCOTTJ]

Thank you for that i've dropped Gibbo and Andy an email and will keep you posted... Any other pointers would be appreciated!!!

 

Reading about fuel pump it sounds like standard Mems ECU has an output that engages fuel pump relay for three seconds to prime it? I assume when honda conversion has been done this is not been available so they have just connected fuel pump relay perminanty. Possibly i need to make a small 555 timer circuit to energise the fuel pump relay for three seconds or so??

 

Another issue i will need help with is:

 

The Honda gear box has six gears it is easy to miss 5th and slide straight over to reverse... Making you have to select 5th and 6th extreemly cautiously!!! While looking around engine bay I found a socket disconnected from a solenoid on the gear box linkage. I plugged this in thinking nothing more of it. Later that day I tried to reverse the car and i could not move the gearstick across to select reverse. Therefore it looks like there is a solenoid that if energised stops you moving the gear stick to the right and accidentally engaging reverse while the car is in motion (Assume this is controlled by standard Honda ECU and speed sensor). My thoughts are to wire a relay up to the brake pedal that controls this solenoid. Therefore reverse can only be selected if the brake pedal is pressed and 4th to 5th gear changes will be streight forward. Has anyone else found this? is there a better work around?

 

Minor issues i know but will help drivability!

[chris_h]

I think your wiring will have been changed when the Honda was done. I think you'd be better speaking to the people that did the conversion.

[Dr H]

I've just completely renewed the fuel system on my S2 Link-up Honda conversion.

 

Does the car have a secondary fuel pump as well as the in-tank pump? Mine secondary pump is activated from a relay but is on the same fuse and goes through the original interia switch for the in-tank pump.

 

I deleted the in-tank pump and now use just a Bosch 044 built into the fuel tank. It runs of the relay and when you turn the ignition on the pump pump up to pressure and then stops. Not sure if there is a timer circuit in there.

[Numbnutz]

Are you using a Hondata kpro or K100 ecu? A kpro will have a square USB port in the side somewhere.

 

The honda and hondata ecu will contol the fuel pump on Socket E Pin 1 (orange I think). This will prime for 3 seconds on ignition and then when cranking or running, (if they wiring hasn't been cut up too much) - you should use this instead of a permanent ignition based feed/relay. There aren't too many wires that need linking from the Honda ecu.

 

Also, the solenoid is to stop you putting it in reverse if the ECU dectects speed above approx 25mph from the sensor in the diff/g'box. If you cannot select reverse at all when connected, then something is wrong somewhere, because the solenoid is only blocks reverse when powered, so it must be permanently powered. I'm not sure if this speed or function is ECU controlled in the Kpro or not, because I've never wanted to change it.

 

"The reverse lockup output controls the reverse lock solenoid, located on the transmission. This solenoid is switched above approximately 25 mph to prevent the shift mechanism from traveling to the reverse gear plane. Only 6 speed transmissions have reverse lockout."

 

If you aren't running a Hondata ECU, then you need to see which ECU you are running and investigate in that direction.

 

If you are running Hondata and are ok with wiring etc, I can help with which wire does what. I'll need to know if you are PRA or PRB type ECU - its written on the bar code label on the ecu. Follow the thick wire trunking on the side of the engine by the head, above the gearbox, towards the rear of the car, and the ecu should be on the end of this.

[SCOTTJ]

This is the wiring loom for the 4 speparate relays to control the crank, old fuel relay and two other relays.... It looks standard Lotus except not with no single MFRU unit... The 4 relays plug in the top 4 standard relay plugs. Only the crank/start relay socket seems to be used, the old fuel relay is not energised. Ideally i wanted to re-use this rather than the one that has been added when the extra fuel pump and swirl pot have been added as the wires are a lot thicker on the standard loom and it uses inertia and cobra immoblier to prevent starting.

 

 

You can see on the bottom two positive brown feeds where +ve has been taken to feed the new relay/fuel pump (See red cut wires). It has been tacked onto the existing wire and need to be re-wired and shrink wrapped correctly once i understand the loom.

[SCOTTJ]

I have no idea what ECU it has... It has what possibly looks like a 9pin serial port. Here is a picture if you recognise this ECU or have wiring / colour codes / pin outs that would be excellent.

 

It would be fantastic to wire up the fuel pump and swirl pot correctly using the ECU to control them. i can't see anycodes or writing on the ECU attached is a picture.

 

You are correct the solinoid is perminatly powered, and the plug disconnected from the back of it and the locking bit of the socket removed. Ideally i would like to sort this with the correct feed from the ECU rather than create my own timer control circuit. If this

 

 

Any help / wiring diagrams would be appreciated....

 

Martin, Andy and Gibbo have got back to me the morning. Thank you for the contact information they are going to check if it was origionally a Motorsport build and find out about the Multi-Function relay wiring. Thank you!

[SCOTTJ]

Dr H, The previous owner found the standard fuel pump was not sufficient when supercharger was fitted at higher RPM. I have renewed pipework, but ideally need to check they have installed it in an optimum configratiuon. I don't know, and cannot seem to get to inspection hatch for fuel tank/pump so i do not know if the standard pump is still wired/working.

 

There is a separte pump fed from the fuel tank which was quite noisy, which i have re-mounted to the bulkhead on rubber mounts and packed to reduce vibration. There is another device that i assume is the swirl pot with +ve and negitive terminals on the top and a small black tank.

 

If you have a diagram of how your fuel setup is that would help greatly or a suggested setup that would be great! I assume the standard pump in mine is not used, but in this case is the standard one removed / by-passed somehow.

[SCOTTJ]

Chris, I know very little about the conversion. I just know it goes like a rocket but has a few minor niggles sorting that have been added since the origional coversion. Still not sure if to keep as it is extreemly track focused, the S1 seems a lot more raw than my S2 Sport 190!!

[Numbnutz]

I don't know what the ECU is, sorry. Maybe if you can take a pic of the plugs and post them here or on Seloc, then someone may be able to identify it.

 

Regarding the solenoid. You could use a relay and some wiring so that if the ignition is on, it is energised. If it is on and Brake pedal on, it is not energised, and if ignition is not on, then naturally it is not energised too - as a work around that would be very simple to put together regardless of the ECU identifiaction. Just an idea.

 

The OEM fuel pump on S1 and S2 is not reliable enough to feed 3.5 bar for SC Honda's, and will probably reduce its life if you try. So the more common approach is to use something like a Bosch 044 inline pump. The original can be kept, and used as a lifter pump, and the Bosch 044 then raises the pressure to cater for 3.5bar + to handle full boost etc.

 

Something like this.

 

 

The better approach is to replace the in tank pump with the same/similar bosch pump but for intank use.

 

A swirl pot is just a pot with 4 or so fuel lines going to it, no wires. When used with a lift pump, this makes sure that the the high pressure pump and fuel supply is not starved of fuel on bends etc under g force, and is usually from 0.5 litre to 2 litres.

 

Take a pic of your bits and we should be able to id them for you.

[Martin R]

Scott, if it is a motorsport car you have another option? Lift the S/C Honda out and flog it. It should be enough to pay for a VHPD build and put it back to standard. It will not be too quick for you then. It will also be a rare beast if you plan to keep it and possibly worth more eventually?

 

I dont know how many Motorsport Elises were built? Not many i bet. IIRC the Exige was a follow on from the Motorsport Elise.