J.E. motors/engineering

[seagrey]

Anyone familiar with their ecu`s.
I have a Grinall RV8 in a Capri with Lucas hotwire,fitted with a J.E. chip.
It`s been sitting for quite a while and massively overfuels,I have swapped a few components I have and tested what little else there is, pressure etc.
I just wondered what sort of diagnostics equipment I might need,is their own software?

[blitzracing]

You just need a fault code reader plugged in, JE just altered the fuel mapping, not the basic ECU software on the 14CUX. Steve Heath sells them or any TVR / Range Rover dealer should have one.

https://delta.securesslhost.net/~shenglt/catalog/i...


Most likely point of failure for over rich mixture could be the Hot wire AFM, testing here:

http://www.g33.co.uk/fuel_injection.htm

You are not guaranteed to get a fault code, especially if you dont run lambda Probes, as the ECU can't detect the wrong mixture. If its not running lambda probes, you can set the mixture up to around 2500 rpm with a screw on the side of the AFM, but beyond that it depends on sensor inputs and the fuel map.

Edited by blitzracing on Friday 29th April 20:40

[seagrey]

Thanks,I`ve cured it now.
Yesterday I found the ecu had the original chip masking taped to it so assumed that it was the case.
I had been told that it was a complete J.E. ecu.
I plugged my autodiagnose,my modis and a friends machines in but nothing other than obvious overfuelling data.

After poking around I found a small box with a multi position sliding switch on it.
It turns out it`s a `switchable tune select resistor` fitted by J.E. when they made the injection loom,they couldnt have hidden it any better,bds!
I set it at one end,fired it up and just kept clicking,by the time I`d notched four on the switch it purred like a kitten.
The top three settings would allow you to run another car off the exhausts alone,
Christ knows what sort of mods you would need to do to a RV8 to require that sort of fuel!
valves the size of pistons for a start.
I must have got knocked when I fitted a new battery.

[blitzracing]

That tune resistor is all standard Lucas stuff, the ECU has 5 internal maps as standard, you just change the resistor to suit the map you want. The big difference between the different fuel maps is the air flow scaling, as bigger or more tuned engines use more air, so the AFM voltage is higher at peak flow, so you have to scale the fuel map to use the whole range. If you put a chip in from a smaller engine, it looses fuelling resolution at low air flows as the smaller engine does not effectively use the whole range.

[seagrey]

The Standars Rover/RR resistor is a single resistor in a clear case just pushed into a loom plug.
This is a small box the size of a pack of ten fags,with a 12 position switch.
Inside are 12 reistors on a simple circuit board marked: Crowley Electronics Corp.USA. the switch is German and the box looks like something from Maplins catalogue.
It has a quality control sticker on it but no other markings.
It has that look that says small production run.
Im just going to measure the resistor which gives the best results,remove the box and replace it with the correct resistor.
Do you know how far this chip will go in terms of mod`s,or was it designed for this particular application?

[Steve_D]

Now you know what the box does why would you not just leave it there and project it from being moved by mistake (bit of tape over the switch)?

Steve

[seagrey]

Steve_D said:

Now you know what the box does why would you not just leave it there and project it from being moved by mistake (bit of tape over the switch)?

Steve

because its situated in the nearside footwell under the carpet right where you would put your feet.
The loom passes by from glove box to engine bay and the box is in danger of being smashed,kicked or stamped on,which is what I would imagine happened to it in the first place.

[Steve_D]

seagrey said:

Steve_D said:

Now you know what the box does why would you not just leave it there and project it from being moved by mistake (bit of tape over the switch)?

Steve

because its situated in the nearside footwell under the carpet right where you would put your feet.
The loom passes by from glove box to engine bay and the box is in danger of being smashed,kicked or stamped on,which is what I would imagine happened to it in the first place.

So if you replace it with a single resistor how are you going to protect that from being stamped on?

I just think the selector box could prove useful and just needs protecting.

Steve

[seagrey]

Steve_D said:

So if you replace it with a single resistor how are you going to protect that from being stamped on?

I just think the selector box could prove useful and just needs protecting.

Steve

The loom from the Ecu runs from the glove box to a large grommet just beneath it,where the loom goes throught the bulkhead,right where your feet go.
The loom cant be moved,which would be ideal but there is too short a run from glove box to grommet,leaving little alternative other than put in a longer wire and situate the box elsewhere.
Considering the fact that I`m not going to be changing the set position its just easier to replace the box with one small resistor in heatshrink pushed into the middle of a bunch of 30-40 wires.
Also pushed back under the edge of the carpet it would leave no bump.

I have also just today noticed that it has low oil pressure,2psi at idle and around 25 at WOT,so its coming out anyway.
Im just into a 6 month break for maternity but my O/H thinks I`m too heavy handed to do too much and generally shoo`s me out of the way,my other daughter goes back to school on tuesday so I have plenty of spare time on my hands.it`s funny how things work out.
I have a sorry looking 4.6 engine as spares,which is in a worse state than this engine.
It was left out side exposed to the weather with the top of the plenum removed but would possibly spend money on that rather than rebuild this one.
As the standard RR ecu for a 4.6 would be no good for my application,would my current ecu and chip be any good,i.e. can it be mapped for the extra 6oo cc and any mods I may do along the way,using my exsisting hot wire set up?

[blitzracing]

You cant make any assumptions about the actual fuel maps that JE modified, as they could be modified on a car by car basis. I dont know why you would have 12 resistor settings, the ECU only allows for 5 maps, and these are split between catalyst use and non catalyst use, depending if the car has lambda probes. In terms of maps generally there are plenty around to try, and the TVR world is a good place to start as they go from 3.5 - 5 ltr in both catalyst and non catalyst mode, and TVR power do them for a reasonable amount. Before you go down that route however, you need a rolling road session to determine where the fuelling is out, plus the engine needs to be 100% (like no fouled injectors etc) before the test. Bespoke mapping is seriously expensive, and there are only a couple of places in the UK that can do it. The most widely used is Mark Adams of Tornado systems, but chips start at £400, plus any modifications on the rollers could add another £400. If you are interested I have developed a box of electronics that goes in line with the AFM, and allows the output of the AFM to be altered at different airflows, so basically you match the AFM output to suit the fuel chip, not the other way around. It does need to be set up on a rolling road however. On the JE modified ECU bit, it is possible that its not the stock ECU, as I know a guy called Franc Buxton who worked for JE did make an alterable ECU, but I think it was not the 14CUX, but a much earlier ECU fitted to the 3.5 ltr engines. Heres his web page:

http://www.stunnedbuffalo.demon.co.uk/sbr.html