Does fuel affect Ignition?

Shaun · Post by **Shaun** » Mon Jun 05, 2006 1:23 pm

Does the fuel side of MS have any effect on ignition? I want to setup an MS-II as an ignition only computer, so if the the MS thinks it is controlling fuel as well will it alter ignition timing?

Any help would be greratly appreciated.

Cheers

Shaun

keithmac · Post by **keithmac** » Mon Jun 05, 2006 1:56 pm

I shouldn`t make any difference at all, the fuel and ignition tables are seperate.

Shaun · Post by **Shaun** » Tue Jun 06, 2006 1:24 am

That is what I was hoping. So the fuel calcs are completely independent of the ignition timing.

So I could build another MS - II and just not run any of the wires for the EFI side of things in the loom and it work exactly the same as an ignition only computer. Excellent.

Cheers,

Shaun

Shaun · Post by **Shaun** » Thu Jun 08, 2006 10:15 pm

No one has disagreed with keithmac so can I take this as gospel???

MegaScott · Post by **MegaScott** » Thu Jun 08, 2006 11:16 pm

For an ignition only controller, you just don't hook up any injectors. There are some sensors you don't need unless you want to use some advanced features, such as Temperature related advance/retard. You still need the MAP connection, and of course you don't need any kind of O2 sensor You could probably get by without the TPS too you should install a install a 1k resistor to ground to prevent unwanted drifting of the TPS input.

If you have a Carb and an electric fuel pump a nice safety feature would be to have the Megasquirt control it.

Shaun · Post by **Shaun** » Fri Jun 09, 2006 2:39 am

Well my setup consists of a Gas Research Throttle body, which is effectively a a LPG carby, turbo and will use the standard tfi ignition.

I was planning on using all the sensors anyway just for the information.

Cheers Megascott

MegaScott · Post by **MegaScott** » Fri Jun 09, 2006 7:38 am

No worries Mate!

(I have to start talking 'Aussie, I'll be in Brisbane this coming week!!)

Cheers!!

daniel505gti · Post by **daniel505gti** » Fri Jun 09, 2006 8:30 am

I have a gas research turbo lpg only car and I found that fuel has no effect on timing, I connected as many sensors as possible or terminating them to ground to stop floating inputs.
The sensors were very useful to check temps and I plan to use coolant retard and inlet air temp retard as well.
I also plan to use mega squirt with a single injector to off set the progression port richness problems I have to over come flat spots.
Acceleration enrichment is going to be the most useful I think. I hope to improve economy and drivability as a result.

Let me know how you go.
Cheers Daniel.

davezed · Post by **davezed** » Mon Jun 12, 2006 4:35 am

Shaun
I too had a dual GRA setup on my car, worked extremely well with MS (extra). Add the temp sensor unit and you can use the cold ignition advance feature, helps with idle on cold starts. You may also be able to rig up an output to squirt extra gas (LPG) using the priming solenoid under acceleration?
Cheers
DaveZZ

Shaun · Post by **Shaun** » Tue Jun 13, 2006 12:18 am

Hi davezed,

Hopefully I won't need to run the extra fuel bit that you are talking about but I would to know more about this extra gas under acceleration.

I will be running 2 fuel lines to 2 B2 converters to 1 s480 throttle body so it should supply enough fuel. I can still moddify the throttle body to get more fuel into the engine as that is where the restriction will be.

Cheers for the info though. I would like to learn more about the extra gas setup you spoke about.

Cheers,

Shaun