MSefi.com read only forum (Jan.15,2018)

A simple solution is to integrate injector pulse output over a fixed time interval. That will give you average fuel flow rate. An RC filter with a sufficiently long time constant will produce a voltage proportional to injector ON time, which is more or less the same thing. As suggested above, you ...

It sounds like you might have a short on the board. You will have to trace it as Matt suggests.

What value does MT or TS show for IAT? Does it change if you disconnect your temp sensor? If it doesn't, there's a board problem.

I was wondering, does anyone have the derivations of the equations used in Megasquirt, such as the AIRDEN equation and the REQ_FUEL equation? I would be very interested in knowing more about these equations. Thanks in advance.

I went through it once using MKS units. For whatever reason, I think ...

When I plug in the same information, in its respective units, into both the standard version and the metric version of this AIRDEN equation, should I not get the same number from either equation?

The quantity will be the same, but the numbers will be different since the units are not the same ...

What's the voltage at the MS connector? I have an LC-1 with DB gauge and didn't have much trouble getting it to work with MS.

I had the same problem running an internal pump external. I switched to the suzuki ltr450 pump to solve it.

:D

Great info!! That removes a number of doubts. I have a second pump that I use for testing.
I was thinking of swapping in case the pump was bad, based on what you say, it won't make any ...

Just one 'off-the-wall' thought occurs to me..... :idea:

Couldn't you tee the relief back into the feed line to accomplish the same thing :?:

I'm all for 'off-the-wall' ideas. It's the story of my life :lol:

As I say, I can't think of an easy way to connect to the relief, it's just a hole.

Shouldn't the pressure relief be plumbed back to the tank? What kind of pump are we talking about here?

This is a on a motorcycle, so I could not fit the pump in the tank.
I enclosed inlet side of the pump with an aluminum tube.
The outlet side of the pump is exposed, so it's operating like an in ...

It's definitely coming from the pressure relief valve.
Even when it's gravity fed, I can see a very small amount wicking around the pump surface.
I was able to tug on the valve spring to open it manually and let some gas out in hopes that it might re-seat properly.
No such luck. It still seems to ...

Has anyone had a leaky relief valve on their fuel pump?

I had a temporary spike in pressure that caused the pump relief valve to open until I shut the engine off.
I fixed the pressure issue, but now the pump drips every once in a while.
I don't think the fittings are the problem, but I'll check.
I ...

Your dash gauge is probably reading correctly. Your engine would have a hard time idling at 19:1 AFR.
As Matt suggested, check the wiring and voltage at the MS connector.
Measure on the CPU pin if you can.
I have the LC-1 with DB gauge. It works quite well when wired properly.

What is your throttle position? Try it completely closed and see if there are any signs of life. Too much air at idle won't work.

Mine idles at 14.1 to 14.5 and its a nice idle. On start up it is about 13.6 and slowly goes up to 14.5. It runs and idels perfect.

That's exactly what I was looking for. I can easily adjust warmup enrichment for a target AFR at a given temperature.
I'll probably shoot for high 12's, maybe low 13 ...

try going into the warmup wizard and lowering the enrichment numbers. Seems rich to me. You can watch the afr numbers as you adjust and pay attention to the way the motor runs. Mine likes to idle smoothest at about 13.5, warmed up. Each engine is going to be different. Billk

Will your engine idle ...

My engine starts and warms up well, I really have no complaints.
RIght now, AFR is quite rich when cold, maybe 10-11.
It slowly improves as the engine warms up and idles smoothly around 13:1 AFR.
I'm wondering if it needs to be so rich when cold?
Is it possible (or even recommended) to have an AFR ...

Disconnect MS from the stim, does the stim have good voltage at all points?
Disconnect as much as possible from MS and check all voltages.

Also check if you have C22 backwards. It might be a tantalum. If so, they do bad things when connected backwards.

Which board?

Remove the CPU, check the voltage going in to the regulator.