MS2 3.57 with a GM HEI8ignition module and diyautotune 10 foot harness
The wiring diagrams and write ups I have found shows to ground the module to sensor ground. Do I use the black wire in the shielded pair that came in the diyautotune 10 foot harness, or the same circuit that is sensor ground for the tps/o2/cts/iat?
the ignition module is the last bit of wiring, and I can see if it runs in the morning!!!
Disclaimer: I've never wired a gm ignition, so this means pretty much nothing.. Sorry for wasting your time :)
All of the silly imports I've worked on use the shielded wires to trigger/ground, with the shield grounded at the MS side and not grounded at the coil side.
I'd be worried about ignition noise messing up not only ignition, but also the other sensors if you grounded them all together. Ignition systems appear to be quite noisy.
You should have a sensor ground. Typically on the head or on the intake manifold. Run all your sensor grounds to that and put a big ring connector (I make them from some 1/4" or bigger copper pipe) on it. The ECU should have a ground wire in there somewhere. Run that to the same bundle of grounds. That's how I do it anyway, and I've done 3, including the one I drove to work today.
If it's a 3.57 and you need to wire something for the ignition trigger to ground, just use the black wire that's in the shielded cable with the white/trigger wire.
DO NOT ground your sensors to the head, use the dedicated black/white sensor return wire for all of them. The rest of the power grounds go to battery negative or block/head.
In reply to Paul_VR6:
got it. got all sensors daisy chained into the black/white. rest of the grounds to passengers head, except for 02 heater ground and battery ground, wich are drivers head. will use shielded black for ignition module.
heres to hoping io hear it run today!!!
Most excellent, keep use posted. Always nice to hear another one running!
Fired right up after jumping the fuel pump relay. Now to find the problem there, button up the rest of the car, and start tuning.
Very nice!!!!
new question:
the fuel pump has a ground circuit coming from pin 37 to the relay. I have this split to the relay for the wideband and the relay for the fuel pump. both relays click when you cycle the key. we have no resistance between the db37 and the socket for the relays on the ground wire to speak of. however, we are not getting the fuel pump to operate without just jumping the relay pins.
it almost seems to me that the relay must be wired wrong, but I know it isn't. any ideas? something I'm missing?
is there a setting to make the fuel pump prime longer for testing purposes? three seconds just isn't enough....
I think it is 5 seconds, if your fuel system is not ready by then I would suggest a bad pump or regulator.
But yes there is a way to alter the prime pulse time.
I don't recall how and a quick search came up with a bunch of cranking pulse width topics. My google foo needs polish.
Pump isn't firing off the megasquirt. If I jump the relay, we build fuel pressure instantly.
So it's electrical.
Just not sure where.
Is there some sort of load limit to the megasquirt for grounding relays? I ask because the fuel pump signal wire is tapped to both the wideband and fuel pump relay.
The V3.57 fuel pump relay output is limited to 1 amp, but that should be OK for two relays.
Does the FP output trigger on a Stim?
Yes. Light comes on then goes off. .01 ohms of resistance from pin 37 to relay pins. Relays click when key is cycled, and the wideband is providing usable data. Just not fuel pump.
Reading through this again, I'm second guessing my relay wiring. Beginning to wonder if I swapped the input and output pins and missed it when I was double checking it last night.
finally found the fuel pump issue. intermittent connection on the furl pump eire from the megasquirt
Dusterbd13 wrote: finally found the fuel pump issue. intermittent connection on the furl pump eire from the megasquirt
video of it boiling tires or we don't believe you!
Ain't ready to drive yet. But getting close.
But trust me when I say that video will happen.
Dusterbd13 wrote: Ain't ready to drive yet. But getting close. But trust me when I say that video will happen.
i trust you!
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