Need GM 350 TBI Base MSQ

[Hoffmanuno]

I had problems with the used injectors on my megasquirt II system I built for my Jeeps built 258 motor. It took me awhile to diagnose that as the problem for the blown fuses in the relay box. I had the MS II PCU gone through by a guy from this site, but by the time I got it back my laptop had died with the Tuner Studio software on it. The following summer I finally got a new laptop, contacted Tuner Studio, and had them send me another link to download their program. Only problem was that they'd updated it since then and so while connecting my MS II module to it, I updated the software and firmware versions. So I was straight up lost in the new version as to how to program anything versus the old one. At that point last year I gave up trying to diagnose it until this Spring. I could never figure out how to configure the new version to fire the injectors. My MS II module works fine now on the MS tester, but I can't get the injectors to fire at all now when I plug the ECU in. It was at least working and running the engine before the upgrade. Basically my jeep's 258 is built enough that it puts out more hp than a base 350 TBI setup with an HEI distributor. I was using the old 350 GM TBI msq base msq as my standard in the old firmware/Tuner Studio software because of this. The jeep has an early/mid90's GM TBI, and GM style HEI distributor, GM coolant sensor/air temp sensor as well. Can anyone build me a good MSQ file that they know should fire my injectors? I need to get this dam thing running and tuned. At this point, I'd take it to a dam pro to tune for me if I can't get this to work. I am using a GM 350 PCM to run it right now. I installed it with its own wiring system as a backup when I had problems programming the system to begin with.

[rickb794]

Extra code is not going to be happy with Megatune. Most here use Tuner Studio, the registered version has auto tune and other features that make it well worth the purchase.

Where are you located? It will make things much faster if you could find some one to get you going.

To many questions to answer to actually build you a MSQ.

MS is not a finished product, it is a tool for experimenters and enthusiasts to roll their own EFI.

Given that it requires a certain level of commitment, and basic knowledge of the nuts and bolts of what it takes to make a motor run. Combine this with a measure of computer knowledge and a heap of patience.

If you stick with it and take the time to learn you will be rewarded greatly. Or you can pay someone to do it for you. The down side of that is every time you want to make a change or have trouble you will have to go back to that person and likely pay more.

The first steps are to read the manual. Then correctly identify each part of your system. Then you can print out the sections of the manual that apply to your hardware. This helps keep you focused and makes it easier to find the pages you need as there are so many variations.

Since I don't recall the 258 being EFI oem, what kind of injectors do you have? You said HEI ignition, is this an all in one distributor with centrifugal advance?

[Hoffmanuno]

Sorry, I meant to say that I have Tuner Studio, not Megatune. I was typing this up at work and mixed up the names.

[Hoffmanuno]

I read the manual years ago when I started and had this all down for the older version of Tunerstudio.
I've read the newer version of Tunerstudio and I can't wrap my head around it.
Had my old laptop not have fried, I'd have been fine, as I could program that version easily.

[Hoffmanuno]

The 258 was a stock carb build from the 80's.
I converted it to an old style Chevy 1988 era type tbi.
The injectors are the stock 350 type that came with the tbi and are brand new.
I'm running a CRT HEI style distributor for my 258.
The air and coolant sensors are the stock GM style I just selected in the Tuner Studio.
I'm running the LS wide band sensor in my exhaust.

[turbo conversion]

If your engine is a 258 then a 350 msq is not going to work very well.

My experience with older firmware and TS vs newer versions is the newer versions have been stream lined making tuning easier than before.

David

[5.0Thunder]

you have a wideband controller for MS to get info from? Can you update your firmware to latest on your ECU, then create a new project in TS, then post MSQ from that project here for us to build upon? That way it'll be easy for you to just load it right into your ECU.

[Hoffmanuno]

I can try to make another msq, but figuring out how to get the injectors to fire on the updated firmware/Tunerstudio interface last fall had me fail miserably.

[rickb794]

So this is your distributor? http://www.crtperformance.com/crt/distr ... etail.html

If so you are probably best to start with a fuel only setup.
That distributor has both centrifugal and vacuum advance that would need to be locked in order to use it for an ignition trigger.
Will a 4.0L locked distributor fit in the 258? You could switch to that after getting a fuel only setup running.

You will want to trigger off the coil negative, the tach lead off your HEI.
See section 5.2.1 of the manual here http://www.msextra.com/doc/pdf/MS2V30_Hardware-3.4.pdf

Your TBI unit probably has low impedance injectors so you will need to set the PWM stuff for current control.
Section 4.10.2.3 covers this, under fuel settings tab you will find a menu for PWM settings the blue question mark will help you with settings (start with default).
You will need a v3.0 or v3.57 main board to run PWM, if you have a v2.2 board you will need to use resistors or add a P&H board to run those injectors.

Use the setup guide http://www.msextra.com/doc/pdf/Megasqui ... Up-3.4.pdf to lead you step by step to get the MS running.

I Just noticed you spoke of the relay box in your first post.
Is this a MS Relay board? It is not recommended to use that with low impedance injectors.
The interconnect cable does not have adequate grounding conductors to prevent noise issues from being a problem.