MSefi.com read only forum (Jan.15,2018)

I run a full race, 4 cylinder, OHV engine in both Fuel and Ignition.

The engine used to run on twin 40 DCOE Webers which i have converted to throttle bodies.

The old way of starting was to give 10 pumps on the gas pedal and the engine would fire immediately and then judicious use of the gas pedal would keep it going until it was warm.

Now the engine will fire - just - but will not run until i 'catch it' with the gas pedal and then all is good.

I have tried increasing the Fueling during starting using the wizard but have now topped out! It 'appears' to need more fuel still but i just cant seem to deliver it easily

Is there some way i can replicate the old method of starting? Or any other ideas?

Cheers

Nev

Are you using Tuner Studio? If not, I'd recommend you do. MT will work, but TS has lots of additional useful features and is much easier to use. (no connection - just a happy customer )

The actual starting mixture is controlled by the cranking pulses. After it starts the warmup settings take over.

Are you using (near enough) the calculated Required Fuel setting? If so, I can't really see how you can't get enough warm up enrichment.

yes i am using TS

I think its the cranking pulses that i cant get long enough, and i am 'topping' out on the wizard. The VE table looks good and 'sensible' throughout the table considering the nature of the engine.

It needs 'alot' of fuel to get going unfortunately. Hot start is much less of an issue.

Maybe i should increase the Req_fuel upwards a whole digit and then re-tune the VE table and see if this makes achieving starting easier, although this would be a major head ache. It feels and appears fine every where else i have tuned it!!

All good fun though.

Post an MSQ/MSL and a datalog and probably a bunch of people will give it a lookie-see.
Otherwise we can only give a guess.

And do you have the MAP sensor connected to all 4 intakes and buffered?
Otherwise the MAP will bounce all over the place.

What is it's idle kPa? I'm guessing pretty high, but I havn't done ITBs,,,, - yet.

Thanks
Holl

You can have a look at mine in Success stories.
"16 MPG around town, 502 powered '59 Cadillac"

Holl

Ok,

Thanks for the info.

I do not have a MAP as it's all on Alpha.N I did think of trying a MAP but I thought it might just clutter everything up especially as it's an inlet over exhaust scenario, I.e. Non crossflow.

I will get some logs over the next while or so and post them up.

Once again thank you