Young_olds
Young_olds New Reader
7/22/20 12:15 p.m.

I bought a scorpion a few weeks ago that was fuel injected back in 06. The ignition died on me and have not been able to get it to start again. Idk if it's me or the ecu but injectors won't fire, I'm not an efi guy and that's as far as I could get. Anyways looking to trade for a dual carb set up( feel free to make a cash offer). It ran really well, better then I expected based of what I was told the engine has in it. I'd also accept help getting it running again as is if anyone thinks they can help.
 

Young_olds
Young_olds New Reader
7/22/20 12:16 p.m.

Pictures don't want to load out here at the job site, I'll try again when I get back to my room.

Stefan (Forum Supporter)
Stefan (Forum Supporter) MegaDork
7/22/20 2:12 p.m.

If the ignition died, then I suspect the tach signal that the ECU is looking for from the ignition is missing.

Verify you have tach bounce on cranking and fix that and you should be able to get it running again.

If you're curious you can connect a laptop to the ECU via serial cable and watch the sensors while you crank.

Download TunerStudio from here: https://www.efianalytics.com/TunerStudio/download/

Install and open Turnerstudio.

Connect via serial cable (or buy one of their serial to bluetooth adapters)

Power the car on and see what you get.

You can also do things like start a zoom meeting on your phone or laptop and others can join to lend a hand remotely.

If you do get a Bluetooth adapter you can connect via laptop/phone/tablet without stringing a cable.  Kinda handy.

Anyway, post some pics when you get chance, you can upload pics here directly using the button that looks like "a pair of mountains with the moon"

Young_olds
Young_olds New Reader
7/22/20 7:21 p.m.

It has spark after replacing the coil and module( megasquirt is set up for fuel only) and I'm confident I hooked everything back up the way it came undone, unless a wire came off and I was unaware. 
 

here is a bit better description I posted on msextra. https://www.msextra.com/forums/viewtopic.php?f=4&t=73550&sid=a0a68e6bd9a6ed49c628344623817a2b

Young_olds
Young_olds New Reader
7/22/20 7:26 p.m.

Pictures.

Young_olds
Young_olds New Reader
7/24/20 7:56 p.m.

I thought I had a trade worked out but looks like it may fall through. Still looking for trades, cash offers or fix help.

Error404
Error404 Reader
7/24/20 8:11 p.m.

Looking at the MS forum thread and based on my recently acquired knowledge with loose MegaSquirt connections I would recommend removing power and checking your connections before reloading the firmware to the MS. This is a straightforward process, takes about 10min, and worked for me. My cam and crank sensor wires had become disconnected and even after reconnecting solidly, I wasn't getting signals, my TunerStudio dash was kinda funky, and the car wouldn't start. I reloaded it, rebooted TunerStudio, and it fired right up. 

Edit: You can get a free copy of TunerStudio, missing some fancier options, and you should be able to get firmware very easily. Then you just need a connection and computer.

Young_olds
Young_olds New Reader
7/24/20 10:19 p.m.

Thanks for the tip, I'll try it and report back after I get home from this work trip.

Young_olds
Young_olds New Reader
7/30/20 6:56 p.m.

In reply to Stefan (Forum Supporter) :

I am not getting any movement on the tach while cranking. 

Young_olds
Young_olds New Reader
7/30/20 7:24 p.m.

some testing showed that when these three wires are connected( the way it was when I bought it) the ignition won't fire. If I take the black(body ground) wire and the grey "ign" wire(from the ms) away from the blue wire(distributor to ignition module) the ignition will fire.

the black wire is a ground, grey is from ms and the blue wire is going from the distributor to the gm hei module.

Error404
Error404 Reader
7/30/20 9:05 p.m.

If MS doesn't see RPM's it doesn't give fuel. For one reason or another, you have a cam and/or crank position sensor problem. Or something is going on at the distributor. I know nothing about using an ECU with a distributor running spark but I could see a bad ground/short there being the cause of your no rpm issue. Do you know how your tune is configured to get the RPMs? Does it use cam/crank or is it going off of the distributor? I know the answer is in the manual but I'm not gonna scroll through it tonight. Maybe tomorrow, at work.

Is there an inline fuse? Did you reload the firmware to the MS? I strongly recommend that, based on my recent experience. A wire connection came loose and I had 0 rpm, even after reconnecting, until I reloaded the firmware.

I would also take a look at how a failure in the coil/module could effect the MS, maybe a voltage spike or something that took out your spark and corrupted the MS.

Young_olds
Young_olds New Reader
7/30/20 9:39 p.m.

There is no crank/cam position sensor, signal is from the distributor. I do not know how to load/reload anything. 

bentwrench
bentwrench SuperDork
7/31/20 10:56 a.m.

First of all that label is deceptive, that is not an MS3 it has a v3.0 mainboard, and is a MS1 or MS2.

What is inside the shrink wrap on that wire that the blue wire is coming out of?

Often a fuel only setup is triggered off the coil negative, but it is not something you want to try experimentally.

Where does the other end the gray wire go? if it goes to the MS which pin? In todays harness the grey wire goes to a ThrottlePositionSensor. That grey wire is labled IGN, and in MS terminology that is  pin 36 which is ignition out and would not be used on a fuel only setup.

Where does the second wire off the coil negative go? (brown or black with a white stripe) To your Tach?

You can go after it the from other way and find which wire is coming off pin 24 at the MS.

That MS is running a super old version of firmware, it's "extra code" which is advanced over the B&G code, but over 10 years old (maybe 15).  (The Extra team releases code updates about twice a year)

Finding a manual that covers it may be a challenge.

If it was me I'd update the firmware and reconfigure for full control, but for you to do that, you will need to "become" an EFI guy.

Another consideration is I am in Portland OR and can have that running for you pronto!

If you wish to learn, you first need to ID what you have, then you can chose a path to move forward.

Post pictures of the top and bottom of the circuit board and I can tell you what you have and how it is configured (there are jumpers inside the MS to configure it).

Young_olds
Young_olds New Reader
7/31/20 12:34 p.m.

As far as I can tel it's an ms1 v3.0.

Young_olds
Young_olds New Reader
7/31/20 12:49 p.m.


the large grey wire is the one connected to the distributor seen in a previous post. It splits off, outer wire is going to pin 2 and the inner wire with white insulation is going to pin 24.

Young_olds
Young_olds New Reader
7/31/20 12:52 p.m.

All the wires connected to the coil are factory wiring, the ms1 is only connected to the ignition by the grey wire tapped into in of the leads from the distributor to the ignition module.

bentwrench
bentwrench SuperDork
7/31/20 1:09 p.m.

The shielded wire going to pin 24 is your RPM input.

Not sure where it goes on the car though as it is jumpered to the Vr input conditioner. 

Perhaps it shares the input to the smart coil?

Young_olds
Young_olds New Reader
7/31/20 2:03 p.m.

Is the vr bout conditioner the outer wire going to pin 2? On the other end they are twisted together and spliced into the ground wire and distributor wire. 

Young_olds
Young_olds New Reader
7/31/20 4:56 p.m.

It runs! Turns out that the outer wire in the  "ign" wire was supposed to go to the ground( pin 2) and the inner white with was supposed to be connected to the distributor( pin 24). I swear it looked like all four were spliced together as the car came to me. I am still interested in trading or selling so I can run carbs.

Young_olds
Young_olds New Reader
7/31/20 10:35 p.m.

I went for a drive finally, not fixed yet. It runs and drive as it did before but when I turn the key off it will not start until I disconnect the pin 24 wire from distributor and reconnect while the key is on. Also either the tune needs work or the ecu is not playing nice with the ignition. Rough idle, a quick rev in neutral almost sounds like it's going to die then it catches up, and it starts "breaking up" at higher Rpms( almost like a soft rev limiter but the Rpms will still climb).

 

bentwrench
bentwrench SuperDork
8/1/20 11:50 a.m.

I'd add a MS2 processor, an idle speed controller, and a Wideband O2 sensor, cheaper and likely better performance over all than carbs.

The only way carbs would beat what you have is individual runners, and it appears you have quite a challenge to fit that in the space you have.

If you have a wideband you can tune what you have, but a MS2 will add so much.

There are other things to look at as well, like that TPS. Is it a rheostat or an idle switch type?

Young_olds
Young_olds New Reader
8/1/20 6:21 p.m.

Not interested in putting more money into the efi setup. Willing to work with what I have. I have the opportunity to buy a weber dcoe setup that was on another scorpion with a 2.0. 

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