Stock Injector Megasquirt Constants

[ZeroKewl9]

Does any one know the exact Injector characteristics of the Stock injectors? I've been looking on here and havn't found anything yet because from what I can tell no one is running an aftermarket ecu with stock injection setup. I'm pretty close to right because I have the car running so so but if someone knew some exact #s for me than i'll tie that info in and leave that alone and just concentrate on the tables.

 

For those of you who don't use megasquirt the required fields are as follows

 

Required Fuel (ms)

Injector Opening Time (ms)

PWM Current Limit (%)

PWM Time Threshold (ms)

 

Those should be the major things to help me target specifically the Stock OEM injectors and i'd need that info on both of them.

 

Thanks lots

Zero

[Tom_Cat]

I am running a FuelinjectionPro (uses the same software) with the stock injectors. What year is your car? If you have one small and one large injector you way want to run 4 squirts per cycle to compensate for the deferent injector sizes.

 

The best thing to do would be to use to large injectors (green), this would give you over 2,000 CC a minuet. :wink:

 

Here is the constants and enrichments page on my setup.

 

Required fuel: 6.2

 

Inj opening time: 1.3ms

Bat voltage correct: .2ms

PWm current limit: 100

PWM time threshold: 25.5ms

 

Speed density

4 injections per cycle

Alternating

Four stroke

4

Throttle body

Injectors: 2

250KPA

Even fire

 

I remind you this is set for 4 injections per cycle, at two injections per cycle the “required fuel†would be 12.8ms

 

If you pm me your email addy I will send you two files. My latest, supper smooth idle, good low end toque and fuel mileage.

 

Two, a two injection per cycle that has good top end. :twisted:

 

Tom Cat 8)

[Dcrasta]

Thats a pretty slick solution . I bet once you get it dialed in you will definately see some drivability improvements.. Way to go mang.

[ZeroKewl9]

I hope this

 

 

Inj opening time: 1.3ms

Bat voltage correct: .2ms

PWm current limit: 100

PWM time threshold: 25.5ms

 

that you provided will do the trick!!!

 

The thing with MS with dual table is that I have to setup constants for each table (injector in my case). I am doing my best to replicate that of the OEM setup. Make it idle and cruise ( <3000rpms) on the single small inj. Then once the car sees boost and/or >3000rpms it will use the secondary inj to hose down the intake.

 

I bet that those settings you have nicely provided (thankyou BTW!!) should be the same for both. My tuning buddy isn't around but he should be here next week or so and i'll put those settings in before then and see what I can do then once he gets here we'll fine tune it.

 

Thanks

 

Zero

 

Oh yeah the car is a 87 CQ

[conquestpa]

HOw are your duty cycles looking? It would really be helpful to have specs on these injectors...

 

Im sure there around somewhere.

 

I would think with TPI you would run the one injector on one of the injector output banks and one on the other.

 

There is modified megasquirt firmware / coding out there the you could set it up for sequitial injection, but I think you have a pretty good setup there.

[87quest-TSI]

bump

 

I would like to see more about this.

[87quest-TSI]

ok so who has done this?

I'm thinking about trying it.

I want to run the Megasquirt for fuel and use the stock ignition. Can this be done?

Any info will be helpfull.

[ESIrType?]

ok so who has done this?

I'm thinking about trying it.

I want to run the Megasquirt for fuel and use the stock ignition. Can this be done?

Any info will be helpfull.

 

Yes, this can be done for sure. Seeing your name has "87" I'm assuming you havue an 87. You can use your stock injectors with the megasquirt. Now keep in mind, and after market stand alone is alot of "trial and error." I've been MPI'd and MegaSquirted with msns, but not running spark yet. I'm using the other extra features though. Ok that was off track. I've been running it since about the beginning of the summer. I'm still playing and changing things. I'm not even close to being done tuning. Mainly because I'm on a NB not a WB o2 yet.

 

My suggestion for you would be this. Use everything you have on the car. Except the MAS. MS now can use a MAS rather than the MAP. I don't like this and our MAS's are to restrictive. Anyways.... You can use the stock CLT, but you'll need to add an air temp sensor. You can use the stock TPS and CLT and 02. I would say *gulp* use the factory harness. This means cutting some wires running to the ECU and splicing in there. Study the wiring diagram and go from there. You can left the factory ECU control the fuel pump. I am at the moment and I think BoostedOne is also, along with others. Now to use the factory CTL (aka coolant temp sensor) you will have to use a proogram to convert for the different values (resistance) it's really easy, then add it to your code. Again, easy. Don't become overwelmed, it's easier than it sounds. Remember all he hard work has been done for us to use the MS. Now I would recommend downloading Megatune and do not upgrade it to MSnS. This become confusing for new users. 8x8 Maps are good enough for you to start with, you don't need the 12x12 MSnS gives you.

Now all the calculations can be done in MS's M-Tune. Start playing and things will start becoming more simple. Now if you have questions, there are a few experienced MS'ers on here, so ask away if you have questions. But remember the real experts are at, www.msefi.com

Something else, I think would make tuning a little easier is run 2 secondaries, plus you have a little more fuel to boot.

 

Your screen may look a little something like this. It's setup for a starter for you. The only thing you may have to change is PWM time thresh, atleast to start with. For VE tables, MS have a prgram to calculate the base tables, remember these are only starting points for you.

 

http://www.csonline.net/starquest/ms.jpg

 

Good luck,

 

Shawn

[87quest-TSI]

Thanks for the info.Shawn.

 

This will be going on my 89.

I am running with 2 secondaries so I'm set there.

I've been Studying the wiring diagrams, but wasn't sure if I needed to have every thing that wasn't going to the Megasquirt still pluged into the stock ECU or not.

But if I under stand this right I should cut the wires that are needed for the Megasquirt and leave every thing eles pluged into the stock ECU.

Am I right on this?

 

Thanks

[ESIrType?]

Thanks for the info.Shawn.

 

This will be going on my 89.

I am running with 2 secondaries so I'm set there.

I've been Studying the wiring diagrams, but wasn't sure if I needed to have every thing that wasn't going to the Megasquirt still pluged into the stock ECU or not.

But if I under stand this right I should cut the wires that are needed for the Megasquirt and leave every thing eles pluged into the stock ECU.

Am I right on this?

 

Thanks

 

Good deal, 2 secondaries I really think is going to make life easier. Yes, basicly what I was saying is, everything the MS is going to monitor and control, cut from the factory ECU. This way the MS is controling and monitoring you system and not the factory ECU. I hate cutting the factory wiring personaly, but I think it's going to be the easiest. You might have to share the CTL wire, so your factory temp gauge works still. Other than that, leave everything sa in in the factory ECU.

 

Shawn

[87quest-TSI]

ok so are the stock injectors high-impedance or low-impedance?

The specs in the sevice manual says there low, but I've seen everyone setting up the Megasquirt for high-impedance.

 

Or am I jest missing some thing here....

[ESIrType?]

ok so are the stock injectors high-impedance or low-impedance?

The specs in the sevice manual says there low, but I've seen everyone setting up the Megasquirt for high-impedance.

 

Or am I jest missing some thing here....

 

The book is right, I believe most injectors over 550-600cc's and higher are mostly low. You can do 1 of 2 things, use some resisters in line or use a flyback board.

 

Shawn

[87quest-TSI]

Well I''ve got the Megasquirt 1 with the v3 board and it has the flyback board

built in to it.

 

So I should be all set then.

 

Thanks

[ESIrType?]

Well I''ve got the Megasquirt 1 with the v3 board and it has the flyback board

built in to it.

 

So I should be all set then.

 

Thanks

 

Sounds like it! Let us know how all goes. I'm sure you are going to go through times of frustration, I think we've all been there. My biggest problem was, was trying to do a little preventive measures, for the tach signal, and cause a big headache trying to troubleshoot my mistake. I found it after about 2 weeks. It was really frustrating, but well worth it in the end.

 

Shawn

[87quest-TSI]

bump