MSefi.com read only forum (Jan.15,2018)

Are you using non-resistor spark plugs by any chance?

Where is the MS grounded?

I moved the grounds directly to the battery with no change.

Basically I am back to my original problems:

1st It starts and runs on warm up enrichment. As the enrichment kicks off it runs worse.
2nd the laptop does ...

Matt Cramer wrote:Are you using non-resistor spark plugs by any chance?

Where is the MS grounded?

Using an Auto Lite resistor plug. The ground is run to the engine block and the negative lead from the battery is hooked to it.

Matt Cramer wrote:Can you replicate either problem on the Stim, or do both the EGO readings and your communications work normally there?

The EGO readings and communication are normal on the Stim.

Ok gentlemen I have the short to ground issue fixed. I replaced Q5 and Q15. That took care of my smoking R20.

Now I have two other issues that are plaguing me.

First when the computer is hooked to the vehicle I can not see EGO voltage. However if I briefly touch pin 16 power to pin 15 ground on ...

trakkies wrote:A resistor smokes because something that it's feeding is drawing too much current. Most likely in this case, Q5 or Q15 has failed short circuit.

Do I check Q15 like a normal transistor? Can I check them both without pulling them out of the board? Thank you for your help.

Due to frustration I took a break from try to fix this computer. I was back at it today and replaced all the items that were smoked including R20. Now as soon as I put power to the Stim R20 starts to smoke again. Does anyone know what will cause this?

Matt Cramer wrote:I've seen voltage spikes pop C16 before. We up-rated C16 from 25 to 35 volts a few years ago to improve durability.

Thank you Matt. I will be placing an order.

Do you still have 5V on VREF when the communication shuts down on the Stim?

Sorry for the slow reply.

I believe I still had 5 volts even with the communication loss. Not sure where to check for the 5 volts on the stim? I did check for 5 volts at the TPS VREF and it was there with comunication ...

Hi Guys,
I have a MSII with a V3 main board that I have been running for a few years with no issues. Started having problems this spring with it going lean under acceleration. Now it does this plus does not want to start and run intermittently. When it does run the problem gets real bad after the ...

Thank you Lance.

Hey guys,
I have a MS2 ECU V2.90 with a MSD6a set up wired per the manual and it works. However, I want to shut off ignition control (control fuel only) and can not figure out how to do it. I am using Tuner Studio MS (Beta) v2.213. I have spent a lot of time looking through the settings and can not ...

Ok thank you Ken. It looks like I just need to do some tuning.
Thanks again.
Kirk

Thanks for the reply Ken. My engine is running low map (30-35-kPa) even at a constant 2800 RPM. Driving it down the road it is still noticeable at the 2800 RPM range but the map is not riding down in the deceleration range.

Hello, I am new to megasquirt and have finished my MSII install on a AMC 360 with a chevy 454 tbi controlling fuel only. I believe that I may be having a MAP issue. When I free rev the engine about 2800 rpm the engine MAP reads low down in the deceleration range of the tables and the AFR is lean to ...