Old Megasquirt is resetting

[ka67_72]

I have an MS1 v2.2 that has been running fine for nine years. It started resetting the past two mornings but running fine in the evening. This morning I was running down the interstate and it started resetting like crazy. It progressively got worse and wouldn't go over 45. This evening I hooked a laptop to it and it instantly died. It did this repeatedly. I cleaned the circuit board with alcohol and a toothbrush. It then ran fine for a while and started resetting again. I disconnected the laptop and the problem went away. I haven't checked the grounds yet. Are there any other suggestions?

Thanks,
Kevin

[Matt Cramer]

Four things to check with resets:

1. Where is it grounded?

2. Does the problem also happen on a Stim? If not, there's probably a noise source on the car.

3. High or low impedance injectors?

4. Any problems with the spark plugs or wires?

[ka67_72]

1. Everything is grounded at one intake bolt. The intake has been recently changed. My plan is to check the ground before I leave from work today.
2. I loaned out my Stim and a spare MS2. Need to get them back.
3. High. Same 42 lb ones I've been running forever
4. Fairly new, but they have been rerouted and coil relocated with the intake swap.

It gets worse with time and seems to be based on load. Idling at a light made it go away for a while. It's like something's heating up.

Thanks,
Kevin

[TheSilverBuick]

What does the voltage and other sensor inputs do when running well then leading up to the reset?

I had a bad solder joint inside an alternator cause a ton of electrical noise that under load would cause an occasional reset. Once the electrical noise was quieted up the resets went away.

[ka67_72]

Our electronics guru at work swore up and down that it had to be a cold solder joint. Against my better judgement, I brought it in and blindly resoldered U4, U5, U7, Q2, Q7 and anything that looked suspicious. It ran flawlessly all the way home. This morning I couldn't get manifold pressure over 10" hg, this afternoon it took 10 psi without a hiccup.

Thanks,
Kevin

[TheSilverBuick]

Cool!

[dieselgeek]

NIce!! pretty cool to be able to service these things yourself, yes?

[ka67_72]

Yes. I have this and two MS-2's. I think I'll go for a 3 at my next purchase. They are super capable and have support like nothing else.

Kevin

[ka67_72]

It's was in the mid 20's this morning and it was acting up again. Yesterday it was in the 50's on the way home. I'm going to swap in an MS-2 and see if the problem goes away.

Kevin