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first semi-successful start
Bizarro - 18/6/12 at 05:38 PM

Started my car for the first time today, had to give it a little bit of throttle to get it to fire but once started it runs OK, a little 'lumpy', and will rev but stalls once I let go of the throttle.

Set up is (all new parts):
zetec 2.0 blacktop
GSXR throttle bodies
Megasquirt v2
Ford temp sensors
Narrow band o2 (4 wire)

Im using the basemap that came installed on the MS. Ive done the basic settings tps calibration, injectors, air/coolant sensors. Ive also set to Alpha_N as per MS instruction for ITBs.

Reading info on ExtraEFI it does say 'if you need to use throttle to start, reduce cranking pulse width at relevant temp'. I did try this but not sure how much to reduce by and it didnt seem to make any difference.

With no throttle the butterflys in my throttle bodies are fully shut, sould they be set slightly open? If so how much?

When Im cranking the engine the starter seems to be struggling to turn the enginge (lots of compression), if I unplug everything it will spin fine.

Any help appreciated, Im new to this and find it all interesting and also very satisfying when things go right!

BenB - 18/6/12 at 05:51 PM

Yes, you need to adjust the idle so there's a little air flowing. Usually there's an idle needle somewhere on the TBs that stops the butterflies closing completely.

Bizarro - 18/6/12 at 06:18 PM

quote:
Originally posted by BenB
Yes, you need to adjust the idle so there's a little air flowing. Usually there's an idle needle somewhere on the TBs that stops the butterflies closing completely.


Thanks, just tried it and if anything a little more reluctant to start (nice big back fire in the garage), once running still wont tick over. When revs go below about 1200 it still stalls?
Approx what amount of gap should I have on the butterflies with the throttle closed, 1mm?

daviep - 18/6/12 at 06:40 PM

quote:
Originally posted by Bizarro
When Im cranking the engine the starter seems to be struggling to turn the enginge (lots of compression), if I unplug everything it will spin fine.

Any help appreciated, Im new to this and find it all interesting and also very satisfying when things go right!


When you say unplugged do you mean ignition disconnected or the plugs removed?

If it is spinning faster when the ignition is disconnected but the plugs are still fitted then you need to reduce the amount of advance on the ignition as it is firing to soon and and the starter is struggling to keep the crank turning as the cylinder pressure rises while the piston is still going upwards.

Cheers
Davie

Bizarro - 18/6/12 at 06:57 PM

No didnt have plugs out, just ignition disconnected.

Think I need to do a bit more reading re megatune software, I can find cranking advance in ignition settings?

big-vee-twin - 18/6/12 at 08:19 PM

Have a look at the warm up enrichment puts a little extra fuel in to start with.

Also with ITB'S you need to have the tick over slightly higher because you have no Idle valve to control the air at tick over.

Mine ticks over at about 1100rpm when cold and speeds up slightly when warm.

Try using Tuner studio you can download it for free and its much better than megatune it also has good base maps built in

Bizarro - 20/6/12 at 03:45 PM

Got a new base map from Phil at EFI today, loaded it into MS and started first time, sat ticking over no problem really pleased.

Its still a bit 'lumpy' but gives me a good starting point, think I now need to do some reading and a bit of fine tuning..

matt_gsxr - 21/6/12 at 06:51 PM

Have you balanced the throttle bodies? This can make a big difference at idle and just up from it.