Hall effect 36-2 sync loss at idle

General support questions and announcements for MS3. See also MS3 manuals.

Moderators: jsmcortina, muythaibxr

Post Reply
decs
MS/Extra Newbie
Posts: 31
Joined: Sun May 24, 2009 5:21 am
Location: South Australia
Contact:

Hall effect 36-2 sync loss at idle

Post by decs »

Hi all,

I've got a problem that is causing me all major of headaches. Engine is:
Nissan RB26
Custom 36-2 trigger on the crank
Honeywell 1gt101dc hall effect sensor with a 1.3mm air gap, wired to 12v
1230cc low-z injectors
Splitfire coilpacks (wired in wasted spark)
MS3 v3.57 with ms3x.

The jumpers and pots are set up according to this:
http://msextra.com/doc/ms3/ignition.html#geartooth

Basically, during cranking I get perfect rpm. As soon as the engine fires it starts getting sync losses. Changing the pots and/or the jumpers around makes it only worse. With boths pots fully counter clockwise i get no rpm signal at all.

I've scoped the signal coming from the sensor and its great. The signal at the cpu isn't so great though. The only thing i can think of is that the injectors are creating terrible noise????? Any thoughts?

Attached is an msq and a log of it trying to idle.

Any help is greatly appreciated. It's driving me nuts!!!!
1989 Nissan Skyline R31 - RB30ET, MS2/Extra
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Hall effect 36-2 sync loss at idle

Post by Matt Cramer »

Could you capture a tooth log of the problem? That will give us more to go on about sync loss.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
decs
MS/Extra Newbie
Posts: 31
Joined: Sun May 24, 2009 5:21 am
Location: South Australia
Contact:

Re: Hall effect 36-2 sync loss at idle

Post by decs »

Hope these help. I couldn't get it to idle this time. just cranks fires skips and repeats the process.
1989 Nissan Skyline R31 - RB30ET, MS2/Extra
decs
MS/Extra Newbie
Posts: 31
Joined: Sun May 24, 2009 5:21 am
Location: South Australia
Contact:

Re: Hall effect 36-2 sync loss at idle

Post by decs »

also, sometimes the fuel pump primes for 3sec or so, others it primes for about half a second. does this mean anything?
1989 Nissan Skyline R31 - RB30ET, MS2/Extra
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Hall effect 36-2 sync loss at idle

Post by Matt Cramer »

Unfortunately, neither log captured enough continuous data for me to see clearly what's happening. Was it synced up while cranking?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
decs
MS/Extra Newbie
Posts: 31
Joined: Sun May 24, 2009 5:21 am
Location: South Australia
Contact:

Re: Hall effect 36-2 sync loss at idle

Post by decs »

If I do something to stop it firing, like disconnect the coils, the fuel pump, or injectors, it cranks and syncs up fine. Cranks at about 180 rpm. As soon as it fires and the rpm goes up to say 3-500 it starts loosing sync. Very hard to get it to run at all, so its a total fluke to get a decent log of anything.

I'm starting to think megasquirt doesn't like these sensors. Seen a few threads where people give up and fit a vr.
1989 Nissan Skyline R31 - RB30ET, MS2/Extra
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Hall effect 36-2 sync loss at idle

Post by Matt Cramer »

I'm wondering if it's noise from the ignition. Are you using non-resistor spark plugs by any chance? How old are the plug wires?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
decs
MS/Extra Newbie
Posts: 31
Joined: Sun May 24, 2009 5:21 am
Location: South Australia
Contact:

Re: Hall effect 36-2 sync loss at idle

Post by decs »

No they are resistor type plugs. It doesn't have leads. They are individual cop coils with built in ignitors running straight off the ms3x spark outputs. I was thinking it was the injectors.
1989 Nissan Skyline R31 - RB30ET, MS2/Extra
Post Reply