Megasquirt always on

[ragepower]

Hi

Im doing this installation http://www.msextra.com/forums/viewtopic ... 1&start=60

And I have this problem which I think in on the main board.

After I wired the idle valve, I have always 7V on 5V pin (Vref) and MS won't turn on

If I disconnect the idle valve, MS will turn off.

The idle valve is a 3-wire valve, and is wired to injbank1 and injbank2.

Any suggection?

[jsmcortina]

The idle valve needs to get power from the fuel pump relay. Does it?

If you really have 7V on TPSVREF you will likely damage the Megasquirt. Unplug the MS3 card before testing further.

James
EDIT. Typos

[slow_hemi6]

The supply to the idle valve (and most things) has to be mastered by the fuel pump relay as shown in the wiring diagrams.
http://www.msextra.com/doc/ms3/hardware.html#wiring

[ragepower]

If you teally have 7Von TPSVREF you will likely damage the Megasquirt.

I think it is OK, since after that I unplugged the idle valve connector and I started the engine, and it was working fine.

Next time I will check the wiring.

[ragepower]

The supply to the idle valve (and most things) has to be mastered by the fuel pump relay as shown in the wiring diagrams.
http://www.msextra.com/doc/ms3/hardware.html#wiring

Mastered by fuel pump relay or 12V switch supply isn't the same???

If not, what need to be fuel pump relay mastered and 12V switched supplied?

[slow_hemi6]

Have a look at the diagram I have linked to.

[ragepower]

Have a look at the diagram I have linked to.

Ok, and vanos solenoids?

EDIT: I need to confirm on car harness but according to wiring schematics, it has a relay controlled by OEM ECU (I think now is controlled by 12V switched) that will supply coils, injectors, idle valve, EGO,...

My question: fuel pump relay activation circuit on MS is capable to control 2 relay (fuel pump and idle, coil,... relay)?

[ragepower]

Ok, I re-wired the idle valve and now it is controlled by fuel pump relay. (it had 12V from battery )

I checked the 5V signal on CPU socket and it was Ok. I just need to check with the fuel pump relay activated to see if is OK too.

Why this happen? Will the flyback circuit on main board, supply the ms? I said 7V on TPSREF but it isn't? It showed 7V on battery voltage on TS.

[jsmcortina]

Why this happen? Will the flyback circuit on main board, supply the ms? I said 7V on TPSREF but it isn't? It showed 7V on battery voltage on TS.

Yes, it is backfeeding through the flyback diode.

James

[ragepower]

I have the same problem.

When I test without running engine, it work the way I want.

When I start the engine, it won't stop. If I disconnect the idle valve, it will stop.

[jsmcortina]

I thought you already fixed that wiring?

James

[ragepower]

Yes I did. I checked and when I turn on the fuel pump, it will power the idle valve, the wideband modules and the injectors.

I did the last post on the workshop, and when I was coming back home I may figured out the problem or the second part of it.

Now the idle valve are supplied by the fuel pump relay. And fuel pump relay must be supplied by 12V switched, right? And if FP relay has 12V battery? It would be the same problem.

[slow_hemi6]

Once again if you refer to the wiring diagram........ The key brings on the Main Relay which is supplied by the battery. The Fuel Pump is supplied by the Main Relay and is controlled by the ecu. If you turn the key off, the Master relay disconnects supply to the Fuel Pump relay and there is no possible back feed.

[ragepower]

Ok the problem continues.

I had re-wired the fuel-pump relay, it is supplied by the 12V switched and it will supply the idle valve,...

When I connect the idle valve, the engine won't turn off. If i disconnect it, it will turn off.

I tested it with TS, on test mode. Fuel-pump on => idle supplied, fuelpump off => idle not supplied.

If I remove the fuse the engine will turn off. This fuse will supply idle valve, 2 MAF and 2 hall cam sensor.

The cam sensor uses the same circuit of PT4.

Any suggestions?

[ragepower]

Solved, don't know where was the problem, just changed it from one 12V switched to another 12V switched wired.