MS3X checklist issues

[webb1624]

Hi all. I am having a few issues with my first MS3/MS3X install. I have not started the vehicle yet. Just doing a pre flight check list on a few things. I purchased the MegaSquirt 3 w/ MS3X expansion V3.57 pre assembled. The first issue is one of my fans. One fan I am controlling thru the fan control output using IAC1B(wire color Blue/Red). It seems to be ok. The 2nd fan I am controlling thru the Advanced Engine Programmable output. I am using IAC2B(wire color Green/Red) for this one. With power to the MS3X, the fan doesn't run(which it shouldn't). I can also turn the fan on and off with the active value. When the power is turned off to the MS3X the fan comes on and stays on. I have checked the relay, and have it wire according to the MS 3 wiring.

Second issue is the fuel pump. When turning power on to the MS3X the pump will prime 3 times. When turning power off to the MS3X the pump will prime 3 times. I have the priming pulses all set to 0 and it still does this. My car is a 1988 Mustang that was originally a 4 cylinder and I am using the Purple wire from the MS3X to trigger the Tan/Light Green wire on the fuel pump relay. I read somewhere that this was a configuring issue. I bought the unit preassembled so its my understanding I didn't have to configure this unit.
The engine was originally in a 1998 Ford Explorer. I am using the 36-1 wheel and the Ford coils and doing sequential fuel injection.

Any help would be greatly appreciated

Chris Webb

[Matt Cramer]

Is the fuel pump relay getting power with the key off?

For the stuck fan, which of the two outputs stick on?

[mr_minnis]

I will have to check my notes when I get home on the wiring. I am not sure if it being an ex 4 banger would change anything. The MS provides ground to the Fuel Pump relay. I am curious what it does when you do the "fuel pump test". Does it stay on ? When I did my 88 mustang I used the wrong wire either the tan/ green or the pink/ black. I switched to the other one and it fixed it. I don't think my pump kick on at all though.

On the fan I would check to see if IAC2B has voltage or a ground and check the relay wiring according to what you find. It sounds like to me the voltage trigger for the relay and ground are swapped.

[webb1624]

Problems fixed !!! Well the first two anyway. I am using a dual fan set up on the cooling fans. One is wired through the factory relay with the MS3X switching ground with the IAC1B output. That one works fine. The other fan I wired up a relay to activate the fan at a certain temp with the IAC2B output. I wired the relay with 12 volts constant to terminal 85 and terminal 87, and was switching ground on terminal 86 with the MS3X. What was happening is that when the key was on everything worked fine because the MS3X had power and was switching ground on the relay. When the key was switched off, the MS3X had no power and the constant 12 volts on terminal 85 was back feeding across the coil in the relay which went back to the MS3X and was finding ground somehow which caused the fan to run with the key off. I ran a switched 12 volts to terminal 85 and the fan is now working like it should with the key off. This also solved the issue with the fuel pump priming. The fuel pump now primes 1 time when turning the key on like it should.

My next issue is that I don't have any spark. I checked it with 2 timing lights. I am using the QuadSpark module wired with 2 Ford factory Explorer coils with the Explorer 36-1 wheel. I can make the coils fire in the output test mode so I'm assuming that it is wired correctly. I almost positive I have the VR sensor at the 36-1 wheel wired correctly. Would I get no spark if I had it wired backwards? I am thinking I read somewhere there is a way to reverse polarity to the VR in the program w/o having to rewire it. Can anyone confirm this?

What's my next step in checking for spark?

Chris

[Matt Cramer]

Next step on the spark is to confirm you have a good RPM signal while cranking.

[webb1624]

I have no RPM signal while cranking. The 36-1 crank wheel is factory Ford. It was a running engine in an Explorer when I pulled the engine out. Could my VR possibly be bad? How do you check it? I am getting .350 ohms across the 2 terminals. I have the Tooth #1 Angle set to 80.

Thanks,

Chris

[Matt Cramer]

0.350 ohms, not 0.350K or 350 ohms? That sounds like the VR sensor is shorted out.

[webb1624]

I could have had the setting in the wrong place on my meter. The VR is good I just had it wired backwards. I had to adjust pots R52 & R56 all the way CCW and I got a signal from the VR. Engine cranks and idles but needs tuning. I am sure the ignition and fuel tables are not close to where they need to be.