RPM not synced
 

While troubleshooting my no start on a 1990 1.8 no vvt swap with ms3x, I see a rpm not synced in red at the bottom of tunerstudio and believe this is where my problem lies. Any ideas why that would be showing up would be great, thanks!

Post a composite log.

This one is all i have, not sure if it is long enough.

That's a regular data log, not a composite log.

Damn, well i guess ill need to throw it in again and figure out how to do a composite log :(

https://cimg5.ibsrv.net/gimg/www.mia...a628d34859.png

Use this tool to create a "composite log" of your crank & cam signal. You have to crank for a long time before it starts recording (20 seconds maybe?). See in the bottom right where it says "0 of 0"? You will get data once it creates about 5 sheets.

sweet, I'll try to get that done tmw!

Ok here is my composite log i took today

crank sensor is wrong. check the sensor to teeth gap.

I think OP is running a CAS. Claimed it ran ok on stock 1.6 ECU?

There's no crank signal. Check wiring and/or the pot settings on your MS3(X)

Still need a crank signal

Truf.

But the fact that it ran on his OE ECU (stated in previous thread) points me towards a problem with his ECU. Either a pot adjust or maybe he missed a pull-up resistor or something.

OP: did you clock your pot?

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Still need a crank signal.

Yes, Prior to taking that log i readjusted r56 counterclockwise 12 times and then 7.5 turns clockwise and the others were adjusted during assembly according to the instructions on trubokitty.

Ok... You mentioned that the motor runs on the factory ECU. Does it throw a CEL code? IIRC, no crank signal is code 2. I don't know why it would run without a crank signal though. Also, have you tried just swapping in a different CAS sensor?

how do you have it wired up for CAS to the ECU?

No check engine light but the car runs rich at all times according to my wideband but i doubt that its anything major. I daily the car so i don't want to risk any major downtime of switching out parts when they should be working correctly if the car is running fine. I haven't done anything to the cas wiring except i believe i had to extend the wires when i swapped in the 1.8. I also just remembered i think i used a smaller or larger gauge wire than the factory wiring, could this cause the sensor voltage to be out of wack and not have the megasquirt pick it up?

I'm not sure how sensitive the ms3 is.

I followed that page completely during assembly, i don't know what i'm missing.

can you show pics of board and harness?

Hopefully these are sufficient. Thanks

OK, constructive criticism time here...

I have only ever built a DIYPNP, and never a MS3X. I'm not familiar enough with the circuitry to spot an obvious mistake. Having said that, I have professionally soldered PCB's before, and I see a lot of issues with your soldering job. It's always a little tough to tell in a photo what's solder and what's just camera flash off of flux, but it looks to me like you've got solder bridges across some locations (3 prong- guessing transistors?). You also have a lot of cold sockets.

My recommendation is that you get a decent soldering iron with adjustable temperature and a fine soldering tip. You may also want to buy some small side cutters for trimming leads, and a solder sucker for removing solder. When you reheat a socket, you'll need to flow a little more solder into it to make it join. It's not so much the extra solder as the extra flux that's helping to make the bad join good. Spend a few minutes on YT reviewing a good "how-to" video. You need to be able to tell by looking at the leads whether you got a good flow of solder or not.

Also, one of your pics looks like you have a torn trace on the PCB. I can't tell if the yellow wire is there as a repair?

Yea this is the first pcb i've soldered before so that's to be expected. For the transistors i'm quite certain they aren't bridged, as i've taken a really close look to make sure of that before but those are quite the bitch to get right so i'll take another look. The yellow wire is to replace the broken trace.

Also just to confirm, Would using different gauge wire than stock for extending the cas wires be a potential cause for no crank signal?

Does it still run on your OE ECU?

Yes, it runs fine on the stock 1.6 ecu.

I'm not 100% certain, but I think the stock ECU will run the 1.6 with just the CMP signal.

I don't know if it will or not. It should throw CEL code 2 if it's not getting crank signal though, and OP says no CEL codes.

If it was me, I'd try either a known good CAS while running on the ms3, or try disconnecting the crank signal wire while running on the factory ECU. If a known good CAS makes the ms3 work, it was a bad CAS. If disconnecting the crank signal wire while running the OE ECU DOESN'T make a difference, you know it's a problem with either the CAS or crank wiring in the harness, but the OE ECU doesn't care.

But again, looking at those pics of the ms3, my gut is a bad solder join that needs some love.

carrera95 - where are you located?

I went over and desoldered/resoldered most of the connections last night and they definitely look a little better but every point looks connected. I noticed i missed a capacitor on c23 and put that in and gave another test start but still no rpm. I also noticed i omitted the A/C in and out wires because my car has no A/C but do these wires have a different use?

I'm in Toronto.

there is a good bit of soldering that looks insuffecient. I am not expert and have made my fair share of mistakes when building an MS. I suggest getting someone to go over it for you. i see where you have already had an issue with one of the IAC circuits and the lead burnt out.

I had the exact same issue last year, and your composite log looks identical to mine (other than the rising/falling edge difference):

yours:
https://cimg7.ibsrv.net/gimg/www.mia...b2337e88e7.png

mine:
https://cimg6.ibsrv.net/gimg/www.mia...00a5458504.png



I had to adjust my R54: https://www.miataturbo.net/megasquir...0/#post1355522

hopefully it's as simple as that for you too.

Hmm interesting, would i be able to sit there cranking it while slowly turning r54 until something shows up or is there a better way to see if that is the cause?

the two transitors on the bottom of the board. q22 and q24 iirc, is the solder bridging the leads?

without seeing your composite log they looked suspect, and i bet that's the issue (if the pot resistor is actually tuned 7.5 turns CW)

I really don't think so, how easy would it be to burn one up though because i definitely got one pretty hot and it looks like it has a bit of some yellowish glaze on it...i'll try to get a picture.

It's worth a shot. I tested the voltage output on mine with a +12v source on my kitchen table, but I don't see why you can't just move it while cranking & see if anything shows. Won't hurt anything afaik.

Alright i'll probably just adjust half or one turn at a time and crank after. Will the rpm not synced message randomly disappear if i get the adjustment right and start getting crank signal or is there something i'll have to reset?

Great news! She started! So i made a half turn CCW and went to crank and got it to turn over a bit then die so i tried to go another half turn CCW and got no connection. I ended up going full CCW and then 7 turns CW and she fired right up but running very very rich around 8-9 afrs. So now its time to start tuning i guess. Thank you everyone for the support and bearing with my noobness! :) I'll post another composite log i took of the first start to see if anyone sees anything out of the ordinary.

so you like followed directions?

7 1/2 turns didnt work....7 turns did.