I finally got the car running, fixed a few small air leaks. I attached my datalog and settings. A few questions:

What should my target AFR be for idle?

I see my minimum PW is around 2.0ms. I'm using 2.0 injectors which are very large for the applicaiton. I don't have any idling issues, nor do i have an off idle stumble. Do i leave it as is?

The car is unusually slow, acceleration is smooth but almost nonexistant. I checked the timing and its 29 degrees at 3500rpm. Any suggestions?

All you megasquirt gurus check out my datalog and let me know what you think. Thanks!!



MS II V.3.0. fuel only, stock dizzy with mechanical advance.

If I'm reading your datalog right I think it is pretty lean. At the that moment of time the MAP was 92 which is darn near WOT and your AFR was 15. It should be more like 12.5 there. When in doubt give it more fuel first cause the worst that will happen is that it will stall.

My car idles from 13.4 to about 15.5. Ideal seems to be about 13.8.

Dave

In order to get my car to idle at a reasonable AFR (even 15-16) my REqfuel has to be 20, at which point the engine slows down and sounds rich. Right now my reqfuel is 13. Isn't that a bit high for stock 2.0 injectors and a relatively stock engine(headers, mild head work)?

Thanks

Yarin

First, get a decent idle any way you can and then tune the PWM like the manual says so you don't have to worry about your injectors. Start with no PWM and then tune some in adding a little at a time until the idle starts to balk then take a couple % back out. Get that right first.

On my 2270 my regfuel is 10. But that is just a multiplier for what they call VE. Set the regfuel at what you feel is right and then tune the VE table. Idle is tuned by feel more than AFR. Get it so it idles smoothly at about 1100 rpms. You will see the MAP drop just a bit as you get it right. Idle should be desired RPM with smooth running at lowest MAP. At that point you AFR should be right around 14

I have some questions about whether your O2 readings are right. You description of the way it runs makes it sound rich but the AFR is lean. As an experiment, tune the car to an AFR of about 12.5 at a MAP of 92 like you had above. If it barely runs your O2 readings are off. If it improves your O2 is OK.

Dave

Yarin, way to go!


i am wondering about the cht temperature....it slowly rises up to 180...

I would expect it to go pretty quicly to 215 or so...

do you have a lot of filtering on the input?

I agree with dave....get the idle good first. don't worry about pulse width and the reg fuel.

my req fuel is around 11. something. If you have to go to 20 something it could be how your fueling equation is set up.

are you using alternate or simultan. fueling? 1 squirt, 2, 4 etc. I believe that I am using 2 alternating.

Your fuel pressure could also be low.

Lots of things to check.

are you pinging or bucking? dial out the O2 and accleration correction until you have your Ve map close. It will take a little while, I have been working on mine for a couple of weeks. then dial in the acceleration.

have fun, you are on the right track....

Ok someone kick me....

To get a reasonable AFR on idle my reqfuel needs to be 20ms. At which point my AFR is only 16. So i figure something is clearly wrong. I pulled one injector plug out, nothing changes! I pulled the other injector on the same channel. Same result. Hmmm... so only 2 cylinders are getting fuel. I checked at the connector side, both get +12V.

Is this a megasquirt issue or a cable/harness issue. I'll try to stick some sort of LED hookup on the injector output and see what happens.

Thanks for the advice guys.

That would explain the low power!

Getting all of your injectors to work will help.

Don't be so hung up on reqfuel. This is just a number, which gets multiplied by whatever is in the VE table for your current map/rpm bin. If you lower the reqfuel and raise the VE, or raise the reqfuel and lower the VE, you get the same amount of fuel. Put another way, the reqfuel slides the entire VE table rich or lean.

This morning I got the car to run with reqfuel of 10ms, 4 injections per pulse and alternating. My AFR was around 15. Much better than a reqfuel of 20ms and AFR around 20. Keep in mind my VE table was touched. Clearly is an injector firing issue that was solved or intermittent... maybe. maybe not.

Ok i'm clueless here. I hooked up the injector part of my stim to INJ1 in my relay board. The LED pulses.
I pulled out injector 2, i saw it pulse fuel when cranking. However something strange happened. When removing the injector there was a tiny pressure release of air/fuel. Right after that my fuel pressure gauge dropped from 20 to nothing. System was powered down. Why would this happen? The injector should remain closed and maintain fuel pressure, even when removed from the intake manifold.

I swapped injector connections from 1,3 to 2,4 and the car still ran. Problem must be with the injectors. So to summarize injectors 1,3 inject, 2,4 appear to have problems.

If one injector has issues will it prevent the other on the bank from firing? The impedence across all injectors is roughly 2.5Ohms so that is ok. The injector are solenoid based. If one injector is mechanically unable to pulse due to a mechanical interference (dirt, etc) will this prevent the other injector from firing.

I datalogged pulling each injector connector, its pretty obvious 2 arent firing.

Should my injectors be paired 1,3 and 2,4 ? I don't think its a connection issue, but just in case does anyone have regular d-jet connectors, new or used they could send out? I wish I had a way to test injectors. Over th next few weeks i'll throw something together with a MSI box and stock fuel pump.

Yarin

Did everything work on the stim?

Check that you don't have throttle body injection selected. Are you using a relay board? If you are you can check 12V at the blue block. Get a 12 volt test light and stick 1 end in each female connector on each injector cable and have someone crank it over. Each should flash if it has 12v and the board is providing ground. This where you learn how it all works. It really starts to make sense as you work out the problems.

Dave

Dave, everything works on the stim. I hooked up the injector section of the stim to the relay board and saw the stim led pulse. Port injection is setup. There is 12V at the constant 12V injector block. I checked continuity between the injector harness and the terminal blocks. All is good.

Is there an easy way to give megasquirt a false tach signal using the stimulator? I built a breakout cable for the db-37 connector but didnt have any luck last time. I've learned a hell of a lot about the system and how it all works, i believe i have either a connection issue or an injector issue. Every problem i've chased so far getting this thing to work has required a 'back to the basics' approach.

Get a 12v test lamp. and see if it blinks when someone cranks the engine. If it blinks you know you have signal through the harness to the injectors. Then it's either injectors or connectors. I'm wondering if the D-jet injectors with the L-jet connectors aren't connecting. Just a WAG.

If you see the tach gauge in Megatune showing an RPM you have a tach signal.

Dave

I'll try that tommorow. I'm pretty sure I have a signal at the connectors. As I said I have a signal at the relay board and my cabling shows continuity to the board.

No problem with megatune getting a tach signal. My idea was to use the stim to generate a tach signal so i wouldnt have to crank the engine. I could unplug the other injectors, and see what gives.

Lately if I don't have anyone to help out I crank the engine myself. It's called an adjustable wrench zip tied to my roll cage with the key in the crank position and me controlling power to the master battery cutoff. It works

There might be an intermittent connection problem, not sure. Maybe the injectors got damaged. I already had one injector stuck open. I can't wait till I have this thing up and running properly, enough of these little annoying problems already!

If you suspect injectors, just swop them to the known good firing cylinders and see if the same ones continue not to fire. If the suspected bad ones fire on the known good circuits, then it's a wiring problem. If they don't fire, then the injectors are fried.

Yea, i have a feeling its intermittent. I saw the "bad" injector quirt fuel. But when the car is running there is no change in AFR or idle when i pull that connector. I swapped the two good injector driver lines to the other ones and i could have sworn it worked. I'll investigate tomorrow and see what i find. How could the injectors fry so quickly?

Yarin....lets go back to basics.

the stock injectors are low impedence. So you either need to make them high or go with PWM.

I ran the injectors I sent you as high. I did this by going to 100% PWM and 25.4ms.

You can do this easily by adding a resistor in series. I used some ballast type 10 Ohm resistors.

I also have the wiring connectors for the stock injectors. I had to make new pigtails to use with them. I guess that I should have sent them to you. I am using one for my afr connector right now. They are available at NAPA, I got mine from a foreign auto parts type store. Beck_Arnly part #. They are in the back of the catalog.

I did post the part # here a couple of years ago....I would guess at around 2004 time frame.

I have not been able to completely review your set up., I am not using MegaTune 3.0 yet.

It sounds like you have a bad connection on one bank of injectors.

Let me know what else you need.

Herb,

The system is setup for PWM from the start. Started with default settings of 30% and 1.1ms. PWM is the way to go in my opinion.

I created an entire wiring harness for the engine, but there is always a possibility that the L-jet connectors dont mate with the D-jet injectors properly. It's just odd that both injectors that dont fire are on the same bank. Coincidence? Not sure.

I'll check the output at each injector connector with a 12V lamp and see if that tells me anything. After that i might just swap in two more of your injectors and see what happens.

I'm going to the Hershey PA swap meet this weekend, i have a huge list of stuff that I need. Should be a jolly old time. Thanks for your help. If you don't need you stock injector connectors and are going to scrap them anyway i'll pay for shipping. Let me know. Thanks!

Yarin, I am planning on attending the swap meet also.

you have my #, give me a call and we can get together then.

I will try to bring my connectors.

I will have on my 914club hat...

Herb, Are you going to have either of your cars up there? I was considering trailering my 914 but as always the weather calls for rain.

We'll definitely meetup and hopefully I'll have better news regarding my megasquirt tuning.

Quick thought: You double checked the plugs? Maybe the injectors are working and you have the plug wires swapped or the plugs themselves are so fouled they wont fire?

BTW, a misfire/no-spark will read LEAN. Unburned fuel is dumped into the exhaust along w/ all that unburned air. The WBO2 measure the extra oxygen as lean.

Interesting... Didn't know that unburned fuel will read as lean. I will check the plugs tonight. I have new plugs standing by just in case. My firing order off the dizzy is 1-4-3-2


I've asked this question several times on here but never got a response. What is the right way to connect the injector banks? 1,4 and 2,3? or 1,3 and 2,4?

Thanks

If you have something faster than dialup...I recommend the videos from Innovate Motorsport.....I too got confused by "lean" condition on the WB02...when your engine suffers a misfire with the ignition (no spark), it'll read lean as well, this helped trouble shoot my install...


Innovate Motorsports training videos

Im not familiar w/ the MS. Im running a Haltech on my 911.

If it does batch fire (all injectors going off simultaneously, 1/revolution) it doesnt matter how they are connected.

If it does bank fire (1/2 the injectors are fired simultaneously one crank revolution and the other half the next revolution) then the typical sequence is 1-3 and 4-2. Though, you'll be injecting in the intake stroke on one cly and the exh stroke one the other. Which-is-which will change from day to day but it makes little real world difference.

SMD

Megasquirt batch fires two banks of injectors. Am I correct in assuming that fuel will pool at the back on the intake port and wait till the valve is opened? Is this method an inefficient fuel delivery method or is the result nearly equivalent to individually fired injectors?

Since MS only knows the engine speed how does it know to synchronize the injection banks with spark?

Do I care which bank is connected where? 1,3 to bank1 or bank 2?

the stock L-jet fires ALL 4 injectors every ignition event....d-jet fires 2 injectors at a time....1 intake valve is open (or there abouts), the other valve is closed due to it being on the exhaust stroke...when I made my D-jet electronic trigger setup, I didn't have it phased at all to intake valve opening schedual...car ran fine.

Yarin, no car, can't get the trailer registered....

Besides, I might need my truck if I pick up any cool parts!

Yes, fuel will pool (but in a sprayed gaseous state - not an actual liquid pool). Batch fire and the old CIS injection use this method. Not inefficient - just not as sophisticated as sequential (which is best for emissions and REALLY fine tweaking)

It doesn't syncronize banks w/ spark. There is no need. See above "pooling" statement. If you can get the ringht amount of fuel in the intage runner for every 2 rotations then the engine will run. There is also no care to which injection bank is which. One cyl is in the E stroke and one I stroke when the injectors fire, so either whether its I/E or E/I doesn't matter. It most likely changes every time you start the car (the ECU doesn't know the cam position when the motor stopped;)

I used batch fire on my old 4cyl jeep for years (SDS system - monitored spark trigger wheel and injected 1/4 the desired fuel each spark trigger = 4 * 1/4 = 100% of the fuel you want at each cyl every 2 revolutions. Simple.)

I'd almost prefer batch over bank fire for simplicity, but you can get an engine running very well w/ any of the methods.

SMD

I spent some time on the car today. Turns out one spark plug wasn't firing. Also turns out one injector wasn't opening. So I changed the spark plug and changed the injector. Started right up and idled very nicely.

However my VE table was sort of tuned for the car running on 2 cylinders and in the process of auto-tuning it out i must have fouled another plug from running too rich (i saw 10:1 O2 at times).

Well either way... for a good two minutes I actually felt some power, the car moved nicely. I Was impressed. Here is a pic of the plug that wasn't firing after the drive today. One of these days things will go my way...

Here are a few pics of the install, wiring in the relay box hasn't been cleaned up yet.

Yarin,

If you have nearly stock 2.0L, it might help you to check out my info on the MS forum . I have it posted here. Look for the posting by 3d914.

It sounds like you found the source of your missing two cyls - so I'll avoid that for now.

Like the stock injection system, I have my MS to inject 1&4, 2&3. You get four injector outputs from MS that combine to drive two pairs of injectors. Like Dave and others I'm using the 2.0 injectors with inline resistors (6.5 Ohm IIRC).

I had some screen pics of all my settings, but cant seem to locate them at the moment. I know my RegFuel is somewhere around 9.8, which is what gets calc'd when you enter the appropriate values for the injectors, displacement, etc. I settled on what was calc'd just to maintain some consistency throughout different VE tables.

If you find idle being adjusted by the O2 sensor, you can set the min RPM so that it bypasses sensor until you reach that RPM (above Idle).

Not sure what else you might need, but keep us posted on how things go.

Enjoy

The car RUNSSS!!! Holy crap i'm soooo friggin excited!

Changed another fouled plug. Reset required fuel to 9ms. Loaded base VE maps off a guy of msefi and tweaked em a little. Still running really rich but the thing hauls ass! I was driving around a parking lot tuning a little and it started to cough.. so i decided to pack it in and drive the 1000ft back to my driveway. turns out i run out of gas on the way there. SUCKS.. had to wait 1/2 hr for my friend to come and help me out. funny hot few ppl care to stop and help. Will post datalogs later.

I'm soooo adrenaline pumped right now... thanks for all the assistance from 914club. From here on its fine tuning VE, accel enrichment, AFR, etc..

Time for beer and sushi.