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

The ECU doesn't actually measure the amount of fuel injected. It calculates the duration of the pulse width based on the flow rating that you enter. If you tell the computer you have 50 pound injectors, it will use a pulse width 25ms (numbers I made up).

If you then tell the computer you've ...

not to discourage you (me being 18 as well ) but ITBs on a v8 will have a touchy throttle and might not be nice to drive on the street.


Not true at all. ITB's create a very flat and predictable torque curve. Once they're tuned properly, they are a reall joy to drive.

The big trick to getting ...

That's a pretty mild cam. The wide LSA will give a better vacuum signal, and help with cylinder filling. Should work pretty well as a "torque" cam. It might change your tune a little bit, but not much; depending on what's already there, of course.

The 462 double hump heads were probably one of the ...

Fuel mileage is affected by a lot of things, and engine tune is only one of them.

And engine needs a certain amount of fuel to run. You can't change that. More cubes simply require more fuel. But you can optimize the tune for the use. Lean it out enough that t doesnt run hot, and give it enough ...

Alpha-N means (as you know) RPM and TPS. Based on those two inputs the computer will use a table/map and provide the proper injection squirt.

The tables can be modified by things like intake temp, coolant temp, baro, manifold vacuum, etc. But the basic fuel charge is provided by the map.

My ...

Well, I'm glad I asked. I can do basic wiring, and have completly reqired a few cars over the years. But sometimes these advanced applications get me a little confused. I'm glad I have a place to check my work before I do something.

BTW, Matt, I want to thank you for all your help with this ...

The more I read, the more confused I seem to get. But, I have a question on spare port wiring for relay control.

I won't be using an idle valve at all. So I have IAC1, IAC2, and FIdle ports available.

In the manual I find this statement: "IAC1,2 these are capable of directly driving over 0.5 Amp ...

Yeah, I could. The car already has a bulkhead connecter, and I'm considering re-using it, as I re-use the existing harness. But the one time I disconnected that item was when it came loose and I had to take it apart to fix it properly. One of my thoughts is to eliminate that connecter altogether

I'm resurrecting this old thread, because it already answers most of the questions I have on this subject.

As said above, the pins in the connector can only handle 5 amps. The 20 gauge wires come out of the pins, join together into a 14 gauge wire. That wire runs thrugh the engine harness to the ...

The wire for the Hall sensor needs to be shielded. The shilding is grounded at the same point as the ECU. That's pretty simple.

Running that cable through a bulkhead connecter seems pretty simple also, using three connections.

Does the shielded cable need to be in it's own bulkhead connceter? Or ...

Another thought.

Huge cams create a very poor vacuum signal. If you've set your fuel tables up to run on vacuum instead of or in addition to TPS, the computer will think you're under a big load, and add more fuel. Change it to run on TPS and RPM only.

That's a pretty big cam, sounds like the rpm range would be around 2,500 and up. But, that shouldn't be a big problem for the computer. One of the great things about EFI is that it allows you to run huge cams with poor vacuum signals, and still be easy to drive on the street.

Tuning for a cam like ...

It only fails when it gets hot - no air flow. And the ECU seems to be fine. I'd be looking at the under hood components, especially the relays. Heat them up a bit with a hair dryer and test those components individually. Or, pull the relays and bake them in the oven at about 150* to see which one ...

I've been doing a lot of research, becaue I'm planning on doing the same thing. Every once in a while, I want to use E85 on the street. And I want to use it all the time at the track.

There are a couple of small issues that need to be addressed. The first, of course, is the need for 25-30% more ...

Doing some more searching, I happened to come across this one, for a Ford. It looks like it has 3/8" compression fittings in and out. Has anybody seen one in person?

BWD FFS2 fits '01 Explorer V6, and 99-03 Ranger V6. Tough part to find, though.

I'v been doing some reading - on this board, other boards, and in the manual.

For a variety of reason, I want to run E85. But from what I'v been able to read, there are some problems with the sensor.

1. Some confusion about how it actually works. The GM part seemes to be well mapped out, but not ...

With the stereo off and the headlamps off, running the engine at low rpm's shouldn't take more than about 45 amps or so. And that's a performance engine with a CD ignition system. You can temporarily install an amp gauge and see what your engine is drawing.

An alternater will only produce as many ...

Thanks for the usefull info Lance cheers.

One quick question, A friend is lending me his unit , he says that once the megasquirt has been set up I don't need, as it is only needed for the initial set up and tuning. Is that correct?

Rob

Yes, and no.

The wide bad sensor is critical for setting ...