MegaSquirt systems?

Anyone running any of the megasquirt sys on a first gen x,with stock injectors?

I'm going to use a MS unit on my project (although not a 1st gen, but it shouldn't matter, MS is almost universal) - but the vehicle has not reached the engine-cranking stage. I did build the MS unit though and I am going to use the stock injectors.

Page 48 is when the MS build starts:
https://www.explorerforum.com/forums/showthread.php?t=205817&page=48

witch unit did you use? What all did you have to add or remove to get it to work?

I'm using MS2 - but MS1 should be fine too.

Well it hasnt "worked" yet on the vehicle (real world environment). The only time my MS has worked is during simulation - that is to say it was hooked up to a Stimulator unit which mimicks the engine's sensors and controls. But it should work pretty easily with your 1st gen since the 1st gen I think used EDIS-6 for spark control.

Yea I'm looking at the ms2 but I'm reading about useing a map and different iac,would I have to get ride of my maf and go to map,if so how and where would it go?I wish I could find a how too installation thread for an ex

MS2 comes with its own MAP sensor soldered to the underside of the board. All you have to do is run a vacuum line from the intake manifold to the MS board. As for the IAC, you will have to stick with the stock IAC (and this isnt a problem with MS since it comes with the parts to do so) - unless of course you want to use the GM IAC and fabricate an adapter.

Read the MegaManual - its long but if you can read the entire thing, it will make sense: http://www.megamanual.com/index.html

Sweet thanks.anyone have this system up and running?any comments or dislikes?

IZwack said:

MS2 comes with its own MAP sensor soldered to the underside of the board. All you have to do is run a vacuum line from the intake manifold to the MS board. As for the IAC, you will have to stick with the stock IAC (and this isnt a problem with MS since it comes with the parts to do so) - unless of course you want to use the GM IAC and fabricate an adapter.

Read the MegaManual - its long but if you can read the entire thing, it will make sense: http://www.megamanual.com/index.html

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Wow it was long and so is your thread, awesome build!!! So I'm going to be going with the ms2,I need to be able to adjust timing and the other control options to.I'm thinking about going to a two stage nos system.one stage is going to a 6 injector direct injection and be controled by a wot or tps and the second stage is going to be a tb plate injection and activated by rpm.the ms2 can control both and my efans.still would like to hear and comments or dislike or tips for this system

jd4242 said:

still would like to hear and comments or dislike or tips for this system

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Because MS is pretty universal (meaning to say it doesnt really matter what vehicle you put it in), it might be easier to find MS reviews and installation articles via a Google search.

Yea was just hoping to find someone on our board or someone with it on an explorer that has some kind of experience in useing and tuning it on an Explorer. Seems like its got good reviews everywhere else.I don't understand why more people especially first gen ex don't use it.looks like its a very popular set up when combined with the edis.and its pretty affordable considering its near to impossible to find anyone that can tune a first gen

jd4242 said:

I don't understand why more people especially first gen ex don't use it.looks like its a very popular set up when combined with the edis.

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I think the primary reason is most Explorer owners do not have the need because either A) their vehicle arent up to the level where its needed, B) "tuner chips" are easier to install (and probably cheaper), C) the 4.0 OHV isnt exactly the best powerplant to build power from, D) MS doesnt know how to control automatic transmissions and most 1st gens (and Explorers in general) came with automatic transmissions, and finally E) "if it aint broken, dont fix it".

Also, keep in mind that MS is not OBD-2 compliant. So if you plan to drive the vehicle on the road and your state requires a SMOG check, then you'd have to keep the original ECU running running in parallel so that you can switch over from one system to another when its time to do a SMOG test.

I thought the first gens was obd1 and I can't get a chip unless its burned and made in person and I'm going to be running a lot on nos so the tunability of ms is great.the ohv can hadle a lot of boost or spray its big v6 its really only .6 to 1 liter off from most stock v8s.I don't have egr or any other emissions except the cat and the fuel vapor canister.also they don't test here so I'm good there.I never thought about the trans,how much is controled on a a4ld by electronics?

Ah you're right about the OBD2 thing - I forgot that this didnt take place till 96-ish. As for the trans, I'm assuming the shift points are all electronically controlled.

jd4242 said:

I never thought about the trans,how much is controled on a a4ld by electronics?

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I think only the OD engagement is controlled by the computer....shifting is controlled with a vacuum modulation system.

Edit: I meant TC lockup is controlled by the computer on the A4ld

Edit 2: Here's a link to an archived thread that talks about the electronic inputs for the A4LD: http://www.explorerforum.com/forums//archive/index.php/t-23854.html

Well that solves the trans problem.

Megasquirt is for tinkerers

Megasquirt seems like a system suitable for tinkerers who enjoy spending more time understanding a fuel injection system than using one. While it may be a suitable inexpensive alternative for racing engines with restricted operating variables, I think it would be unacceptable for the wide range of operating variables a typical production vehicle is subjected to.

The typical production vehicle in development is subjected to a vast array of test conditions to determine optimum air/fuel ratios and ignition timing. The knowledge from the testing is stored in the PCM in indexed data tables to maximize performance, engine longevity and fuel economy while minimizing pollution. Establishing the optimum A/F ratio and ignition advance at WOT requires significant testing but is a trivial task when compared to optimization for a wide range of operating conditions.

I suspect the reason that you can't find a response from someone who is using a Megasquirt in an Explorer is because anyone who begins the project soon realizes the effort involved and eventually abandons it. Only those who can't afford an alternative or are dedicated experimenters are likely to achieve a functional system. To those I congratulate their success and admire their dedication!

2000StreetRod said:

The typical production vehicle in development is subjected to a vast array of test conditions to determine optimum air/fuel ratios and ignition timing. The knowledge from the testing is stored in the PCM in indexed data tables to maximize performance, engine longevity and fuel economy while minimizing pollution. Establishing the optimum A/F ratio and ignition advance at WOT requires significant testing but is a trivial task when compared to optimization for a wide range of operating conditions.

Click to expand...

I think you need to define exactly what type of "wide range operating conditions" you have in mind - because MS has a customizable AFR ratio look-up table and can be coupled to a wide-band O2 sensor to ensure operation in varying environments. Don't get me wrong, as I've said, MS is not for a daily driver (lack of OBD2), but it can operate in whatever condition most of us would throw at it.

And I really don't care about mpg or pollution!!! Unless I can find a system that can do and control what the msII can then this will probably be going in with a 110 shot and but sometime after my gears.

Pressure vs A/F ratio

I believe the stock PCM relies mainly on the MAF sensor, engine rpm and throttle position to calculate engine "load" and set timing and A/F ratio according to stored values determined from extensive testing.

I assume that a MAP system uses manifold pressure and engine rpm to set timing and A/F ratio. It is a simpler system and probably much more suitable for racing engines. I believe it is preferred by race engine tuners.

I wonder if there is a set of kPa vs rpm tables indexed by engine coolant temperature and air intake temperature. These are some of the wide range of operating conditions I was referring to. Cold start fuel enrichment in my opinion is essential for an acceptable fuel injection system.

Anyway, my point was that extensive testing is typically performed to determine what values should be stored in the table. Unless the Megasquirt user group has already compiled this data and made it available, it will have to be derived experimentally.

Since Megasquirt supports a knock sensor the stored timing data is less critical because a knock sensor can retard the timing to avoid engine damage. Timing tables can be fairly aggressive to optimize performance since the knock sensor can be relied upon.

RSR fuel injection systems

Below is a link to an article about motorcycle ecu tuning that supports what I said about data tables. The RSR fuel injection systems do not support ignition timing because of the complexity associated with it.

About RSR Fuel Injection