Waiting a long time for first spark, normal?

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460stang
Experienced MS/Extra'er
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Joined: Sat May 29, 2004 8:18 am
Location: Terrace B.C. Canada

Waiting a long time for first spark, normal?

Post by 460stang »

Beta 16 with B18 honda engine. With stock ignitor or VB921 (tried both).

Basic trigger is the only setup that works with the honda pickup using the V3.0 VR input and the honda 4 tooth distributer wheel.

Skip pulses of 3 is the lowest allowable setting, but why?

On an OEM (unless you driving a 88 jeep 4.0L) you get spark way sooner and therefore get a pretty quick start. The honda starts as soon as it get spark (I have watched), but that is not soon enough for an OEM EFI quality start.

Would it help to use a wheel decoder with the 24 tooth sensor that is in the honda distributer to get more acurate timing and quicker starts? Likely I would also have to use the TDC 1 tooth sensor to show TDC which would make this complicated.
88 Stang 7.7L Twin Holset Turbos 95# injectors MS2extra
93 Ranger Splash 2.3L turbo 560 hp 33 psi MSII EXTRA 3.0.3,
81 5.0L TT mustang 440hp 10 psi MSextra,
93 Honda Civic B18 MSII Extra 2.0.
90 S10 350 twin turbo MSII
88 350 Procharged camaro MSII extra.
92 Toyota truck 5.0 swap, rear turbo. MSII
muythaibxr
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Post by muythaibxr »

As posted in the 2.5 features thread, we already know that it takes a while to get spark..

Basically, because we do all the complicated calculations in the main loop (to avoid the ISRs taking a long time to run) it takes a few teeth after sync to populate the arrays that are used to calculate spark timing, by which point, the first tooth to schedule off of might have already passed. James has a few ideas to speed this up, and we're going to try to get those into 2.0 before releasing it.

We also have a few ideas that'll speed things up for COP users.

Ken
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