Mapdaddy problems. (MAP high, baro frozen)

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Chiburbian
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Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

I have been having a problem lately that seems to come when it gets hot outside, meaning 80 degree plus.

I haven't worked out AC issues yet, and the load from the AC might have something to do with this because the problems seem to happen shortly after I turn on the AC and start trying to adjust the VE, which I may be doing wrong but anyhow... But then again, I only get the itch to dink with that pending issue when it's hot outside. I just figued I would mention it.

Anyhow, I have a MS3x with knock, on board clock, and mapdaddy.

I have been tuning successfully for days with both real time barometric data and MAP from the mapdaddy. This afternoon during a drive in 87 degree heat, I noticed my tuningap starting to turn blue in VEanalyze live, where for the most part the map had been getting very slightly red. This followed by bogs on the highway, and I couldn't even maintain speed at 60mph where I had earlier been traveling much faster.

I pulled over , turned my engine off and checked my gauges and noticed that my barometer was locked at 105kpa and my MAP with engine off was fluctuating from about 116kpa and 122kpa.

I attempted to re-calibrate the sensors but they never changed after burning.

I had left my SD card at home on accident unfortunately and was not sure how long my laptop would last in the heat so I wasn't logging to hard drive. (the cheap laptop I got as a tuning laptop tends to shut itself down when it gets too hot).

I only got 3 hours sleep last night due to a clutch install that took longer than expected, so I just reconnected the stock ECU and used that to get me home. I am planning on turbocharging but in the meantime I am keeping the stock computer in the car for just this emergency.

While I sleep away my sorrows, can anyone give me any insight as to what might be causing my intermittent mapdaddy problems? Anything to check or watch for? If I get it working tomorrow morning before work, any specific data logging channels you would like me to track?

Thanks all for your help!
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

I forgot to add, the barometric pressure in my area tends to stick at 100 plus or minus 2.

I did attempt to recalibrate the map/baro. I want to say that in the past going to the page where you pick where your second map or baro comes in (General?) and changing something, burning it, then switching it back and burning it again got everything working. Unfortunately this thought didn't come to me in the heat earlier.
Matt Cramer
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Matt Cramer »

This could be a cold solder joint, but first, try checking the voltage output on the MapDaddy when this happens (ideally, if you can recreate this on a Stim). It should be ~1.7 volts at 100 kPa.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

It will be going onto the stim tonight to test.

This morning before work I decided to screw around with it. I installed the megasquirt back in the car and had the same problem. With the correct calibrations, barometric was 105 (and is effected by adjusting max kpa setting in General Settings page), and the MAP was fluctuating somewhere between 118 and 125. Once again, ambient SHOULD be somewhere around 100kpa.

I then reflashed the firmware on the MS3 and reloaded my msq, and calibrated my sensors. That didn't fix the problem. The other day I added a battery voltage gauge to my tunerstudio dashboard to keep an eye on what that was doing. Sure enough, at idle I was indicating 16.6 volts. I tried manually adjusting the battery calibration page to match my multimeter, but that didn't effect my AFR or MAP to bring it in line with what it should be. I will likely switch it back tonight.

As it stands, I don't know if it is a car/ground/power problem or a problem internal to the MS so it will be going to a known good stim tonight for testing.

I am leaning towards an electrical problem because all my problems seem tied to electrical activity. Even when it was running well, the current draw from raising or lowering the windows would cause the idle to be effected. When the A/C powers up, it draws more current from the alternator. When the fans turn on, it draws more current...

Also, the MS was cool to the touch this morning when I started and ambient temperature was in the high sixties. Not warm enough to give me pause.
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

Put it on stim.

Disconnected mapdaddy from JS5 and tested lead to ground. Read 1v.

The fluctuating map signal persisted though, so I removed the mapdaddy entirely from the megasquirt. I then connected it to the computer and tested again.

Interestingly, I got 400 something kpa. This is interesting to me, because unless the map sensor is measuring a DROP from 5volts, I should be getting 0kpa or whatever the minimum is at 0 volts correct?

Where could my 5 volts be coming from? I am going to consult the megasquirt schematic, but if you have a quick and easy thing for me to check I would appreciate it.
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

Ok, since I still had my original map sensor sitting around, I did a dry fit to see how it would turn out.

None of the map sensor pre-sets (it is marked 4250) gave me any result anywhere near what I know is atmospheric pressure (100kpa'ish), so I set the kpa value of 0kpa to 0 volts, and kpa of 5 volts to 5kpa, and it gave me a result of .7 volts.

I am thinking that I have some serious power issues going on here. Where do I start?


UPDATE: I checked out the following on U2 (MAP sensor board area).

Pin 1 - Verified 1k ohm to cpu header.
Pin 2 - Verified ground
Pin 3 - Verified 5v from cpu
I am unclear as to what function pins 4-6 perform and how to verify they work properly.

I am also not sure how to test C3 or C2.

What is next?
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

Also, just a note - I DID destroy one MS3 daughtercard once already. This is a FRESH card as of two weeks ago and I can't imagine me frying another one so quick. I mistakenly tried to switch a relay straight off of my chip and fried it. Could I have fried something else on the mainboard which is causing my problems?
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

Update for more info:

This morning on a hunch, I metered vref from pad #3 f again and got 4.88v. Is the variation acceptable? I also did a voltage check from the 5 volt header to the ground header and got the same value. Mind you, my power supply is 12.6 volts metered.

I then bent leg #1 of the map sensor back and metered directly off of that. I got .439-.444 volts. It did start to rise but I imagine that is a result of either current warming it up, or the heat from my hand?

Remember, when I created a custom scale in the MAF settings that made 0volts = 0kpa, and 5 volts = 5kpa, I got a result of .7 volts.

Looking back, I metered my wideband:
4v = 17.9
.9v = 11.5

If I put these values in tunerstudio, my AFRs didn't match tunerstudio vs wideband wire. I had to fudge the numbers and adjust by approximately .5 units of air to fuel on both ends of the line for it to match.

Once again, is this a ms3 board thing, or a mainboard thing, and how do I check/fix it?

I will keep digging into the schematics (and mind you, I am learning a lot) but I am very dusty when it comes to analyzing circuits. The last time I did it was 16 years ago in military avionics school. (Marine Corps EA-6B Prowler Avionics technician mos# 6313) Most of what I did in the field was identifying the actual box that was bad or troubleshoot what wire was shorting or open.

Thanks again!

UPDATE: I found that U5 is the regulator. I metered directly off of leg #3 and got 4.96 volts.
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by jsmcortina »

It almost sounds like the reference 5V or 0V are not connected fully at the processor. Do the voltage check with the MS3 card installed (careful not to short out any pins.)

Image

Also check that you have 5V on one side of R4 and R7.

James
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Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

Darn it! I had a half page long post written and walked away from the computer and now it's gone.

I will try and start over with a little editing for space and time.

So tonight when I get home, say I test the pins you mentioned from the top of the MS3 daughtercard and everything comes up ok? What then?

If I test the pins, and one or more of them isn't what I expect, say - voltage is either missing or varies from what I expect, what is the next step?

I am just trying to anticipate a bit here because it takes so long for the back and forth to happen between experts. If I can test two or three steps in advance troubleshooting wise, it moves the process along quicker.

What would cause my chip to not get a reliable connection? Any way to ensure it stays in contact? How tight should the daughterboard be to the main board? when I installed it I thought I put it on with enough pressure...
Chiburbian
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Re: Mapdaddy problems. (MAP high, baro frozen)

Post by Chiburbian »

James: BINGO

I will post more later but the basics are that the daughtercard wasn't seated far enough.

UPDATE: Here is the story:

A couple weeks back I fried my MS3 daughtercard trying to feed it 12v where it didn't belong. Yeah, I was dumb. I got a new card, fixed my mistakes and installed it - but I was afraid to press down quite so hard in seating the card. One riser seemed to have a little bit of separation, but I thought that it might have different pin heights because I did put pressure on it and it didn't move.

I checked Pin 1 and I had an intermittant 5 volts. I then pressed down even more firmly and this time the risers seated fully. I tested again, 5v was consistant. I put the box back together, reinstalled mapdaddy, and tested on the stim. Everything was perfect.

I then installed the MS in the car and verified all my sensors and values. Everything worked fine - but my VE map is still buggered because it had been tuning on a CPU that didn't always understand voltage like it should.

I have since driven the car about 50 miles and the tune is starting to come together. Thanks for the help!
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