Hi All

I have been running my MS in my race care for 4 years now with no problems until now. I have replaced the leading coil, new wires and plugs. But I still have a miss only on leading coil number two. I double checked the wires and plugs by swapping them with number one rotor but the miss still sticks to the leading coil number two. The leading coil has only one power wire (13.65V at idle) and only one ground signal from the megasquirt. So I do not quite understand why it stays on one side. I would think I should have a miss on both sides. Also the trailing coils at this point work fine on both one and two. I also swap out the crank angle sensor to play it safe. Help?????

Best Regards
RX7 Racer

 

MS1 or 2? If its MS2 and you have a way of datalogging when the problem occurs, there is a lost sync counter & reason flag that will trip if it encounters a problem with the CAS signal. If you don't have any loss of sync, then the problem is most likely not in the CAS.

I'd say to check all the joints in the coil itself, and the connections on either end of the spark plug wire. A small dab of dielectric grease inside the plug boot, right at the contact, can help a lot. Just make sure you don't have a trail of the grease leaving the plug, because this will increase the likelyhood of spark jumping off the wire, or of you getting shocked.

 

I have a new coil and all new plugs and wires. I swap them from rotor housing and to the other but the problem stays on the same side.

I have a V3 board with the three pull up resistors MS1 with O29Q firmware. I have looked at some of the electrical drawings but from page to page I can not see how the system actually works. As always you do not learn anything until you have to. So since I have never had a problem I have not had to dig in to the system to deep. Can some one explain to me on how the out puts from the crank angle sensor runs through the board to finally develop the (I assume the ground signal to fire the coils) off of the three pull up resistors. All so I am confused about the drawing (LED Indicators) stating Squirt-1, Warmup-1, and Accel-1 instead of coil trailing and coil leading.

If I can get an in depth explanation or get directed to where I can read up on this area so I can trouble shoot my problem. As most of you know you can not fix anything until you under stand how it works 100%

Before this problem the engine ran strong with out a miss and the engine is a fresh street port and ran 4 races last year.

Thanks In advance
Kim

 

I went to the car and decided to start it and now I have no spark on both coils. Bad news is I do not have a small intermittent problem the good news is now it is not working at all so it should be easier to find the problem.

Any ideas what this failure could be? Both coils have good voltage. On my lap top when I crank it over the tack usually shows cranking rpm but it is not (Reads zero). All three LED show red and bright as well.

A side note I noticed last time I ran it the fan controller is not coming on. I do not think these two are related but I am not sure.

Thanks in advanced.

 

I remember the pots need to be ajusted clock wise to the point to were I loose spark then turn them back a bit so I can get spark. I was told this would help eliminate noise in the system. I wonder mybe due to tempatures and vibration that it could be out of ajustment.

Also I changed over to a S5 NA intake from a S4 for this season and I will check my grounds to make sure I did not miss any of them. I hope that it is some thing that simple.

Any other ideas that I should do toss them over. I need to get the car on the track the weekend after this one.

 

If the laptop does not show cranking RPM, then the MS is not seeing the engine moving. Whether thats b/c the CAS has come disconnected, stopped working (very rare), or the settings on the MS have become corrupted, I don't know. I'd lean towards the settings on the MS though, since the fan controller isn't working. As a first step, try re-burning the version of MS1 extra that you're running to the MS, and reloading the last working tune. Also, if you can post it up here, that could help.

 

I put my jumper in powered up the MS, opened up my Q29 file folder opened to run download-firmware.bat and instead of down loading I get a message saying" The system can not execute the specifided program. Press any key to continue.

When I hit any key the program closes. It is not a com port issue because if I open MS program on my desk top I can see the water temp, intake air temp with the correct readings.

To add to this after trying to access the MS to put in the firm ware. It now has spark and runs now. But I am back to my first post. I have bright clean timming light on leading number one wire but and a weak and a miss on the number two wire leading.

Back to the same question why strong on number one leading plug and weak on number two. Also the down load firmwear problem am I doing some thing wrong there. Last time I flashed the chip was four years ago so maybe I am missing some thing.

 

Is the miss occuring when you have the computer plugged in, when its disconnected, or all the time?

Do you have access to an oscilloscope?

Are you determining that there is a miss just through the timing light, or does the engine noticeably stumble at the same time.

The leading spark for both coils is wasted-spark, so its only a single output from the MS to the coil pack. If it was a signal problem, you'd see an occasional miss on rotor 1 and an occasional miss on rotor 2, not all of them only on rotor 2. This leads me to believe that the problem lies either in the coil for rotor 2 or in the spark plug or wiring.

Next step in troubleshooting would be swapping the leading wires on the coil. If rotor 1 starts missing occasionally and rotor 2 is strong, then its the coil thats the problem. If rotor 2 is still misfiring, swap the plug wires too. Then the plugs themselves. When looking at the plugs, compare them, and see if there's excessive build-up on either due to a possible coolant leak, or over-eager OMP injectors or something.

 

Topless you know your stuff because I did almost all the things you asked in your last paragraph.
Is the miss occurring when you have the computer plugged in, when it’s disconnected, or all the time?

Answer: I have not performed that test

Do you have access to an oscilloscope?

Answer: No

Are you determining that there is a miss just through the timing light, or does the engine noticeably stumble at the same time.

Answer: Yes I can see it on the light and the engine stumbles

The leading spark for both coils is wasted-spark, so it’s only a single output from the MS to the coil pack. If it was a signal problem, you'd see an occasional miss on rotor 1 and an occasional miss on rotor 2, not all of them only on rotor 2. This leads me to believe that the problem lies either in the coil for rotor 2 or in the spark plug or wiring.

Comment: I would agree with you on all points 100% (Read next comment).

Next step in troubleshooting would be swapping the leading wires on the coil. If rotor 1 starts missing occasionally and rotor 2 is strong, then it’s the coil that’s the problem. If rotor 2 is still misfiring, swap the plug wires too. Then the plugs themselves.

Comment: I have no doubt it is not the coil or wires and plugs. Did the old swap with coil, new plugs and wires. Also replaced CAS from another Engine that ran fine. Problem always sticks to Leading #2. I am at the 98% level it is with the MS. I am using the pull up resistors with the missing 2 tooth set up. Is it possible that on every second rotation of the CAS the MS it’s self is not picking up the signal. I ask because I do not know electrically how the MS board works in terms of taking in the CAS signal processing it and sends out a ground or power signal to the coil igniter. Also the fan controller stopped working I have not looked at that because I have a bypass switch on the dash to by pass the MS on the track incase it failed. I just mentioned it in case it is relevant to my problem.

When looking at the plugs, compare them, and see if there's excessive build-up on either due to a possible coolant leak, or over-eager OMP injectors or something.

Comment: Good points to check did not think of possible fouling of the plug. But if that was the case I think I would have the same missing problem with the trailing plug on #2. Trailing plug #2 fire clean and steady on the light. This motor has only about 16 hours of race time on it. It just seated the seals in and now it no longer pulls any oil from the crank case. I will go with your check but I doubt the problem is there any thing is possible.

As I mentioned before I could not reflash the 908 Chip with my firmware I have been using, plus after I tried to do that I lost my Com port. Then after powering the MS off and on the com port reconnected. I then tried to flash the chip but would not take it.

I must be doing the flashing wrong due to the error I received that I mention on my last post. What are the proper steps? Last time I flashed the MS was four years ago at the track.

This sucks first time on the track is next weekend in Portland.

Thanks for you good in put so far.

 

Here is the error I get when I try to reflash my MS1 chip with the O29Q firmware. I flashed this chip 4 years ago with no problem with this firmware. But this time I get stuck here. see attachment screen shot of error.

Any Ideas what I may be doing wrong. No problem with com port connection I check before trying and had a link on port 4 with my computer and MS with the port test showing sucess.

 

With MS1, the only times I had a problem loading new firmware, what worked for me was restarting the computer without the USB to serial cable plugged in (if you have a straight serial connection on your computer, this shouldn't be a problem), doublechecking the port I was using in device manager on the computer, and then doing a complete reflash.

The complete reflash is the option that you choose if you're upgrading from B&G MS1 code, and it requires you to temporarily connect the two holes in the box labeled "BOOT" right above the prototyping area. (http://www.msextra.com/doc/general/pix/v3components.gif) I usually just bend the cut-off lead from a resistor or something (a thin paperclip will work fine too) into a V thats a little wider than the holes, so that when you squeeze it & insert it, the tension will maintain contact with both holes. Then just follow the instructions on the boot loader for the complete reflash. Also, make absolutely sure you disconnect the coils from the MS when doing this or you could and likely will burn them up.

good luck!

 

I found a small error during my testing. I was testing with my timing light connected on the wires up top close to the leading coils (3 inches from were the wire plug into the coil). This is where I was seeing the miss on the light. If I test down by the leading plugs (3 inches away) it shows a miss on one and two leading plugs. Why it shows up that way is strange I did not think it would matter where you located the timing light.

With all the double checking on wires new every thing and grounds, I am sure the electrical system on the car is fine. I also looked at the plug they are good and put a set of new one in (new set number 3). Remover new coil but back original same results will keep new coil as a back up for at the track same with extra plugs and wires. Also fan cotroler not activating and the wires an relay are fine. They work off my bypass switch. This brings me full circle to what was mentioned before. Flash the chip and see if it that may be the problem.

I tried to flash the MS1 chip with my original O29Q firm wear off a different lap top but had the same error as before. I then when back to my original computer and down loaded the O29y4 firmware from the forum to up grade the firmware in hopes to fix my problem. In this case I got to the point of putting in the boot jumper, powering up the MS then hitting the enter key to get an error that down load failed. See attachment (faint but readable)

Any one out there have this problem before?

SCCARX7RACER

 

Form said my attachment was too large for the file type. my error read as follows when trying to load the O29y4 firmwear.

Boot>Down load failed:
Expected response-
Boot>..
But recived this-
Boot>..
Press any key to continue. . .

Then when I hit any key the window closes and im back to the start.

 

Loaded O29y4. Spoke to a person locally I was hitting Y in stead of N at the time of rebooting

 

Glad y4 seems to be working for you. That was the version I had been running up til I switched to MS2.

 

I went on line and from reading up on timing lights (Sun 7501) it will pick up the leading wasted spark as a miss fire due to low compression in the rotor at the time of the wasted spark. So based on how it drives in first and second gear in my parking lot (Strong) I would say I was miss lead with the idea of a small flutter on the light as a true miss on the plug. My so called rough idea must be fuel air mix not quite right for my large street port. Sorry for the miss leading information but I was not aware a timing light would give this type of reading.Thanks for the time to help out. At this point I can go to the track today and see if the lap times show no issues.
Thanks
Scca rx7 racer