Megajolt (again)

Steven 90 · Post by **Steven 90** » Fri May 31, 2013 6:54 pm

http://trigger-wheels.com/store/contents/en-uk/d35.html

Anyone has used this kit on a Range Rover 3.5 lpg V8 ?
Is this better then the rpi kit with a&r amplifier ?
The vehicle is used 4 offroad.

daxtojeiro · Post by **daxtojeiro** » Fri May 31, 2013 7:01 pm

Much much much much better!! You cant compare the 2, the MegaJolt is a wasted spark solution which will allow the coils to fully saturate before they discharge. The other is a waste (of money) Im afraid,
Phil

Steven 90 · Post by **Steven 90** » Sat Jun 01, 2013 5:53 am

daxtojeiro wrote:Much much much much better!! You cant compare the 2, the MegaJolt is a wasted spark solution which will allow the coils to fully saturate before they discharge. The other is a waste (of money) Im afraid,
Phil

Ok thanks for the input, with a normal distributor you have vacuum advance, how is this done with megajolt ?

ChrisJC · Post by **ChrisJC** » Sat Jun 01, 2013 7:25 am

Agreed.

I have a MegaJolt on my 4.6V8. It is basically the kit above, but with the following differences:
- Triggered by the flywheel rather than a trigger-wheel
- MegaJolt modified to automatically switch maps when switching between petrol and LPG.

You have to map a MegaJolt - that is how it does advance. You can either feed it a manifold vacuum signal, or a throttle position. There are probably maps already out there if you have a standard setup. I went on a rolling road to do mine.

Chris.

Steven 90 · Post by **Steven 90** » Sat Jun 01, 2013 10:27 am

ChrisJC wrote:Agreed.

I have a MegaJolt on my 4.6V8. It is basically the kit above, but with the following differences:
- Triggered by the flywheel rather than a trigger-wheel
- MegaJolt modified to automatically switch maps when switching between petrol and LPG.

You have to map a MegaJolt - that is how it does advance. You can either feed it a manifold vacuum signal, or a throttle position. There are probably maps already out there if you have a standard setup. I went on a rolling road to do mine.

Chris.

So there is a connection to put a vacuumline on the megajolt ecu ?
I have a carbu 3.5 and wanth to keep everything so simpel possible.
Is there a difference in power, fuel economy ? in regard to the standard system ?

DaveEFI · Post by **DaveEFI** » Sat Jun 01, 2013 11:10 am

Looks like you have the choice of a TPS or MAP based system. The MAP based is probably easier to do.

You'll also likely need a tach adaptor and USB to serial adaptor.

Steven 90 · Post by **Steven 90** » Sat Jun 01, 2013 6:38 pm

DaveEFI wrote:Looks like you have the choice of a TPS or MAP based system. The MAP based is probably easier to do.

You'll also likely need a tach adaptor and USB to serial adaptor.

I just bought a second hand set from a guy @ my landrover club x-rover.
I have no idea wath TPS or Map is ?

Post by **scudderfish** » Sat Jun 01, 2013 6:42 pm

TPS is throttle position sensor, basically a widget that tells the ECU how far open the throttle is. MAP is a pressure sensor for the manifold that measures how hard the engine is sucking air in. MAP is generally a better measure of how hard the engine is working.

Steven 90 · Post by **Steven 90** » Sat Jun 01, 2013 7:01 pm

scudderfish wrote:TPS is throttle position sensor, basically a widget that tells the ECU how far open the throttle is. MAP is a pressure sensor for the manifold that measures how hard the engine is sucking air in. MAP is generally a better measure of how hard the engine is working.

ok thanks, the kit i bought is with a map and a rpm sensor aparently.
Will i be able to use this sensor to make a rpm gauge work ?

DaveEFI · Post by **DaveEFI** » Sun Jun 02, 2013 7:49 am

The original rev counter is connected to the coil negative. The pulse from that when the coil fires is approx 60 volts.

With EDIS, you have 4 coils. Connecting to just one would make the rev counter read 1/4 of the true RPM. So you either need an adaptor which derives a pulse from all four, or one which converts the low voltage pulse tach output on either the MJ or EDIS unit to one large enough to drive the rev counter. (Modern rev counters are designed to work on a low voltage pulse)

The instructions with the kit should make it clear which version you have.

daxtojeiro · Post by **daxtojeiro** » Sun Jun 02, 2013 7:23 pm

The issue with the vacuum feed that would have fed the dizzy is thats not true MAP. Its a ported output Im afraid (well it is on the EFI plenums, so I assume it would be on a carb too)

If it isnt true MAP then it may be an issue, although less of a problem on a mapped ignition setup. I would fit the MAP feed from the same place that the servo vacuum is fed from, before the valve if there is one, as thats a true MAP,
thanks
Phil

ChrisJC · Post by **ChrisJC** » Mon Jun 03, 2013 5:47 pm

Or take the vac feed from the difflock port on a Range Rover carb manifold, or the autobox port on an SD1 carb manifold!

Chris

Steven 90 · Post by **Steven 90** » Mon Jun 03, 2013 6:06 pm

ChrisJC wrote:Or take the vac feed from the difflock port on a Range Rover carb manifold, or the autobox port on an SD1 carb manifold!

Chris

I have a holley carbu and offenhauser inletcollector. However i think there is a vac feed somewhere on it

SimpleSimon · Post by **SimpleSimon** » Tue Jun 04, 2013 11:42 am

So long as its manifold ported before the throttle butterfly/s jobs a good-un

EDIS 8 has a tach output (IDM pin) but it will not be compatible with an old analogue gauge a Tach converter will be necessary to fool the Tach its getting the correct pulse driven from above EDIS8 IDM pin

you can link the low tension side of the coils with diodes to drive the tach but IMO its a waste of time and causes the Tach to dance all over the place at best (dirty signal)

martyn123 · Post by **martyn123** » Thu Jun 06, 2013 11:33 am

Hi,

Have a Megajolt system on my 5.0 Marcos and once my tacho gets to around 3500 the needle starts dancing all over the place.

The tacho converter you mention, can you be more specific, is there one on ebay you could link me to to or a online shop to ensure i am getting the correct part,

Regards,

Martyn