95 rover v8 nas and E.D.I.S conversion help

[95nas]

Hi to all, I have a 95 Range Rover it runs a 4.6 rover V8 engine and 14 cux EFI. around november 2020, I retrofitted the distributor with EDIS from trigger wheels. all in all the install was easy and somewhat involved. completed in about a day.
I powered and loaded the megajolt "E" with rover V8 software, had a bit of difficulty reconfiguring firing diagram but eventually figured it out.
the road test went fine, engine seems to have good power. I went to overtake a lorry and engine fell flat at 4000 rpm. further review showed I had the megajolt configured for MAP and not TPS. once reconfigured, the engine revved fleely to 6000 RPM.

thru all of this testing I found that as I accelerate from idle, the engine will stumble briefly and then revs normal. this is bothersome as when I stop for any reason and attempt to proceed it gives the impression of cutting off.
if I disconnect the megajolt controller engine revs normal, I plugged my laptop in order to review settings. all looks normal, rover v8 normal aspirated, TPS.
When I attempt to calibrate TPS, I found the TPS gauge display is pegged to 100%. when I cycle the power (ignition key) the gauge will start at Zero, do a complete 180 degree sweep and then back to 100%.
does not calibrate, it will go thru the step of "ensure TPS is at rest" tap next "ensure TPS is at full throtle" I press throtle, tap next and PC displays "rest and full throtle cannot be equal values of 225".
I have attempted this at any throtle position with same results.
I have checked timing advance with timing light, timing does advance upon throtle up. megajolt is wired to SAW pin 3 from edis pin 3, PIP pin 6 from edis pin1, 12 volt pin 1, ground pin 9 and TPS at pin 10 from 14 cux pin # 20.

what am I missing?, what mistake Am I making? why is my TPS read out on laptop pegged at 100%? why does my throtle falter when Megajolt is connected? why does it not allow me to calibrate TPS on laptop?
Any and all suggestions are welcome and greatly appreciated.

oddly enough even thou EDIS is an american ford product and I am in the us, it is not a popular conversion here, hence my reason for reaching across the pond, for expertise.
Carlos.

[DaveEFI]

Not used MegaJolt, but I'm guessing it shares the TPS? Are you certain you've followed the instructions on how to do that, including the grounding?

[GDCobra]

I get the same impression as Dave on this, sounds like your MJ is not correctly receiving the TPS signal and I must admit I'm intrigued by this as I considered using TPS when I fitted my NODIZ system but couldn't work out how to get a signal as the throttle pot is already wired to the 14CUX, I couldn't see any way to fit an additional unit or 'share' the Hotwire's TPS signal, maybe I was not being 'creative' enough so I'm interested to see how you've managed it.

Out of interest why do you prefer TPS rather than MAP? When I looked into this it seemed like MAP was the better way unless you have a poor vacuum signal such as when using throttle bodies or an 'interesting' cam, I didn't think my cam was too wild (I'm now wondering but that's another story) so didn't investigate TPS any further.

[DaveEFI]

I've just looked at the MegaJolt instructions - couldn't find anything about sharing a TPS. And you certainly wouldn't want to parallel the 5v on both MJ and Lucas. So if using the Lucas 5v only, grounding then becomes critical. You don't want the same power ground with high currents flowing as a sensor ground - as sensor inputs measure tiny currents.

I also can't see the need to know the throttle position for ignition timing. Engine vacuum is a better load indicator. And it's unlikely the Lucas injection would work well with a very hairy after market cam.

If you think of the original distributor, the mechanical advance works only on RPM (tach) And the vacuum unit altering that curve according to engine load. So should be possible to produce a map matching that with no TPS.

[GDCobra]

I also can't see the need to know the throttle position for ignition timing. Engine vacuum is a better load indicator. And it's unlikely the Lucas injection would work well with a very hairy after market cam.

If you think of the original distributor, the mechanical advance works only on RPM (tach) And the vacuum unit altering that curve according to engine load. So should be possible to produce a map matching that with no TPS.

That is all exactly as per my thinking Dave which is why I went for MAP and didn't pay any more attention to TPS. Only reason I was thinking of it again is that now I have a MAP sensor and can see the read out in the Nodiz software I can see that I'm not pulling quite as much vacuum as expected.

This is not an area I've done any in depth analysis of but from what I've read on t'Internet it seems expectations are around 18-22"/Hg (oh boy do I hate that measurement scale!). The reading from my MAP is around 55KPa, bear in mind this is measured absolute (lower reading means more vacuum) so this equates to around 13.5"Hg, as far as I can tell. Time will tell if this is likely to be a problem.


Anyway, apologies for thread hijack.

[95nas]

Gents, thanks for the reply. I upgraded to EDIS because the distributor and related items were becoming difficult to manage in terms of reliability. it has over 300,000 miles. (chassis and distributor, all else has been renewed).

while doing my research, I kept on coming across different distributor set ups from various manufacturers here in the states. nothing rover oriented. anything from overseas originated in the states and was customized for rover set up, this plus shipping put the expense out of the $1,000.00 budget.
megajolt seemed to be the best choice.

as much as I researched, I failed to find info on TPS and MAP control. when I received the trigger-wheels kit, the ml-E was set up for TPS only but literature spoke of having capability for both MAP and TPS control. In retrospect I would not mind having MAP control.

literature explains that TPS is used as a reference for the timing advance to take place. I guess I suppose my next step is to contact trigger-wheels for the option to convert current controller to MAP and or procure a unit with MAP capabilities.
Carlos.

[DaveEFI]

Looking at the logs for my standard cam Vitesse unit running MS2 and EDIS, I idle at around 35 kpa

[GDCobra]

Looking at the logs for my standard cam Vitesse unit running MS2 and EDIS, I idle at around 35 kpa

By my quick and dirty calculation that's around 18-19"/HG which is around what I expected myself. I can only think it is the cam which is influencing this higher pressure.

[GDCobra]

Gents, thanks for the reply. I upgraded to EDIS because the distributor and related items were becoming difficult to manage in terms of reliability. it has over 300,000 miles. (chassis and distributor, all else has been renewed).

No need for any excuses to ditch the dizzy. I'd want rid of it if everything was brand spanking new, I believe Noah used this technology on his arc.

[DaveEFI]

Assuming your engine is pretty standard, you should have no problem getting a nice smooth MAP signal from the plenum - just ignore the existing dizzy vacuum take off, as that doesn't give the full engine vacuum. T into the fuel pressure reg one - or fit another in the vicinity. Threaded brass barbs of the correct size are easy to obtain - just drill the plenum and tap a new tread for one.

I only know of one RV8 with MegaJolt/EDIS. That is a 4.6 running Mark Adams modified 4CU injection. The ignition side seems to work very well, and as far as I know, doesn't use a TPS. I made an initial map for it based on the dizzy specs in the BL manual. It's been on a rolling road since, but haven't seen if or how they modified that.

[GDCobra]

Assuming your engine is pretty standard, you should have no problem getting a nice smooth MAP signal from the plenum - just ignore the existing dizzy vacuum take off, as that doesn't give the full engine vacuum. T into the fuel pressure reg one - or fit another in the vicinity. Threaded brass barbs of the correct size are easy to obtain - just drill the plenum and tap a new tread for one.

The MAP signal is smooth enough just not very much vacuum (not sucking very hard). I'm metering from the pressure regulator port (not ported) so I do see full plenum signal at idle. I've checked for leaks and I'm higher advance at idle than with the dizzy as the system is no 'seeing' the vacuum signal at idle, this means the IAC is closed further than before which should all help idle vacuum. Only thing I can see it being is the cam which unfortunately I didn't assemble and have forgotten what the guy who built the engine said he used. It's certainly not a real lairy cam but may be enough to drop the vac'.
I'm also planning on putting another gauge on it to check the reading against the MAP sensor when I get a chance.

I only know of one RV8 with MegaJolt/EDIS. That is a 4.6 running Mark Adams modified 4CU injection. The ignition side seems to work very well, and as far as I know, doesn't use a TPS. I made an initial map for it based on the dizzy specs in the BL manual. It's been on a rolling road since, but haven't seen if or how they modified that.

I'm guessing if that is a 4.6 and and MA tune it will be a 14CUX rather than 14CU (Jimmy) which I think is the earlier flapper variant.
I've also used a Mark Adams chip in mine, can't remember if it was Tornado or Optimax but to be honest wasn't that impressed with it, I've currenlty got a tweaked TVR map built on the latest program and this performs better IMO.
But agree, based on everything I've read, MAP seems to be the way to go unless there is a good reason not to.

Not familar with MJ but would have though that changing from TPS to MAP would simply be a software setting (and hooking up a MAP sensor, which I thought was on-board on MJ?).

[DaveEFI]

No - It's an SD1 and still on flapper injection. MA did a 'controller' for the 4CU which allows a crude control of the mixture.

[GDCobra]

No - It's an SD1 and still on flapper injection. MA did a 'controller' for the 4CU which allows a crude control of the mixture.

I'm probably getting confused, I've only really dealt with 14CUX, thought 14CU was the older flapper system, just been looking for some info' on it and it seems that's not the case, I then thought the flapper one was 13CU but seems I'm wrong again. Not my day!
All of the above are Hotwire type systems.
However it also looks like 13CU & 14CU were US and possibly small amount of other markes (Swiss), didn't think it came into the UK.

Seems a strange decision to make when there is so much equipment available for the 14CUX system, particularly on a 4.6 and then getting it tuned, but each to their own I guess.

[95nas]

Ok lads, I have resolved my situation.
turns out to be it was a blunder when I wired the MJ/E, for some reason, I misread the pin location of pin 2 and pin 10. according to instructions (and my personal notes during install), pin #10 is to be used if using TPS. TPS signal on 14CUX is taken from pin 20. pin #2 on MJ4 is listed as Vref or voltage reference to TPS, "if MJ4 is map, leave unconnected". well further reading states or asumes that ML4 is being used in conjunction with Mega Squirt, thus MJ4 would supply reference to Mega Squirt TPS. basically I was back feeding voltage to 14CUX TPS thru its signal wire.
I re read all my foot notes, install notes and instructions and looked at the multi pin socket of the ML4 and realized my blunder. pin #10 was empty and thus I wired it, tested and voila. all read well, load chart showed TPS value, TPS gained ability to calibrate and all works well (for now). next upgrade
a stage 4 rpi cam.

[DaveEFI]

No - It's an SD1 and still on flapper injection. MA did a 'controller' for the 4CU which allows a crude control of the mixture.

I'm probably getting confused, I've only really dealt with 14CUX, thought 14CU was the older flapper system, just been looking for some info' on it and it seems that's not the case, I then thought the flapper one was 13CU but seems I'm wrong again. Not my day!
All of the above are Hotwire type systems.
However it also looks like 13CU & 14CU were US and possibly small amount of other markes (Swiss), didn't think it came into the UK.

Seems a strange decision to make when there is so much equipment available for the 14CUX system, particularly on a 4.6 and then getting it tuned, but each to their own I guess.

The SD1 model is an EFI, which came with the Lucas 4CU (flapper) injection as standard. So to change to a different size engine pretty straightforward, if you change the short engine, and he wanted a top-hatted 4.6 block anyway, so not just a complete engine swap. Changing the injection quite a bit more work. Besides, if changing the injection and wanting rid of the dizzy at the same time, a MegaSquirt etc would make far more sense.