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Megajolt- Blurred lines under timing light...


Quagmire

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Right, so my 3.5 90 is finally running on Megajolt! Everything appears to be running smoothly and it starts much better, runs more smoothly (it didnt feel rough before, so this was quite a surprise) and pulls better, first tank was 1.5mpg better on consumption too :)

However, on checking my trigger wheel- vr sensor alignment i found that it is running at about 6deg BTDC on EDIS alone, rather than 10deg. This is not a problem as i will adjust the position later but have compensated in MJ for now.

The thing that i wanted to ask about was this- my timing marks show up as a blurred line, rather than a single white stripe. Instead of seeing a nice 1.5mm line, i am getting a blurred stripe about 4-5mm thick- is this down to my timing light, or could i have a problem with EDIS somewhere? This makes timing things a bit of a guess which i don't like. :ph34r:

Next question is this.

I run the vehicle on LPG 99% of the time, only using petrol when I am out of gas. The LPG is a single point, closed loop system whereby the liquid fuel is vaporised and then fed into the carbs as a gas via mixer rings. A lambda sensor reads the EGO and controls a stepper motor to control the flow of gas and achieve the correct mixture. This is all fine, however at idle I can get some hunting as the system plays about with the mixture.

The system has connections to take a reading from a throttle position sensor, the idea being that at idle the system goes "open loop" to prevent hunting. However, being a carbed system, running MAP sensing I have no TPS.

Could I use the Megajolt outputs in some way to fool the LPG control box into thinking that it is seeing a TPS in the closed/idle position? I was thinking i could take an output triggered at say <800rpm...

Thanks :D

Jamie

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you could use one of the user outputs of the jolt, but it is either on or off.

I dont know how difficult it is to mount a TPS on your spindle, but I might try that.

what does the lpg look for? Low voltage at low revs from TPS at idle or high?

I think that you might need the user output to go low at less than 900rpm.

Bear in mind that the outputs switch to ground, and are current limited to 500mA

So to do this needs at least a 24 ohm resistor connected to the user output with the lpg sensing from the resistor.

examples from autosport labs

MJLJ_User_output_examples.png

If the lpg system allows you to set a threshold then it would be easy

RR

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Try another timing light ! ……………. The simpler the better………..Some timing lights seem to be affected by wasted spark ….. especially dial back type timing lights and often these will show twice the wanted timing. Have a google search ……….there are many issues with timing lights & wasted spark ………. but not quite so bad with true multispark systems.

With the 90 (MS/EDIS) I gave up with the expensive ‘snapon’ light and purchased a cheapy Gunson light ………. Perfect.

Multispark was / is only available on EDIS4 and only on the later modules. I have done a lot of research and it seems that it was never an option with EDIS6 / EDIS8.

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