We had the car running pretty good for the last week until Sunday. It's a 4.6 2v with cops and MS3 with expansion card. I took it for a ride and after a while it started to act like it was running out of gas. Well seeing how the fuel gauge isnt right thats what I thought. After going to get gas I was able to get it home and pump the fuel out the tank so I could drop it. I found that I had 13 gallons. WTH. Doing some thinking and reading I was under the conclusion that the dwell was set to high and possibly heating up quad sparks or coils and cutting out. So last night I burned the new settings in and fired her up, everything sounded good. Tonight I got and started to clean up the wires in the floor board so we could go make some pulls and she wouldnt start. TS shows the red not synced button and 0 rpms while cranking. Replaced the vr sensor and cam sensor with some extras I had laying around. The pins from the vr sensor to ms harness plug has continuenty. Did a datalog while trying to crank and had 0 rpm, lost sync count 0, and lost sync reason 0. Tried the trigger logger and had 0 pulses. I don't know if it's normal in the state it's in but the mat show 170* and kpa reads 197. Any thoughts???

 

KPA shouldn't be reading 197 unless your engine makes 15 psi of boost while cranking.

I would try reloading one of the tune files from when it was working and see if that makes any improvement.

 

Last night we tried restoring to an older point. Today I reloaded the tune that I used to do the first start up. Unfortunately nothing has changed.

 

I found a firmware update (1.2), updated and installed original tune. Still no luck and gauges in TS going bonkers. Removed MS from car and hooked it to the stim to try to rule out any odd ball wiring issues. KPA still reads 180+, tps works but jumps around, if you turn mat just barley it will go from 180 to -20 and bounce back to 180. I think something is wrong in the MS. What.... I have no idea. Come on Cramer, give me the easy fix! lol

 

Funky man, sounds like a hardware issue or you burned something out. But don't listen to me, listen to Matt!

 

I have had this problem before I listened to everything that everyone had to say and the only thing that fixed it was updating the firmware and INI file. Then I uninstalled and reinstalled Tunerstudios, also checking the vr sensor gap (it must be tight). I use a vr sensor and wheel and when installed I had to adjust the VR POTs.

look here for how to flash the ms
http://www.symtechlabs.com/support/knowledgebase/megasquirt:flash#ms2_extra

look here for adjusting the vr pots
http://www.megamanual.com/ms2/vradjust.htm

NOW YOU HAVE MS3 I KNOW IT MIGHT BE A LITTLE DIFFRENT SO MATT COULD TELL YOU EXACTLY

 

Exactly what sort of MAP sensor are you running? High MAP readings can either be a settings error or something (very) wrong with the hardware or firmware; let me know which sensor type you have, and that will give me a better idea of what's more likely to produce that specific reading.

 

I believe it's xp4250

 

Thanks for the help guys. Shes up and running again!

 

Glad to hear it - what finally solved it? Reloading firmware?

 

Oops didn't read rest of thread.
Good job getting it going.

 

Reloaded all the firmware and TS. Everything is back to normal.

 

Hey Matt what do you think could have caused this issue? I have had it to me two times in the few years that I owned my ms2. could it be voltage spikes or noise?

 

That's certainly possible; voltage spikes can corrupt firmware. One particular issue I've seen has been spark plug wires in contact with any wire to or from the MS. Also, where is your MS grounded?

 

I dont mean to hack your thead but this should benifit me and 1hcam.

I placed my main megasquirt ground on to the shock tower just like the factory did it on my f-body. also my battery is in the truck in case you would ask me to place it directly onto the battery ground.

I have been looking online for similar problems and I seen a few people saying that they have voltage spikes and drops. I belive PFTuning said they add a 47uf 35v cap onto the middle legs of Q3 and Q9, with the negative lead going to Q3 to stop this issue from happening.

Im going down to radio shack today and picking a few things up. Ill see if this eliminates this issue.

 

So it seems the megasquirt dose not like the capaitor too much. it did fix the voltage spikes and drops but seems too laggy and does not want to respond to well to changes that are made on the tune.