Suzuki 1.6 Turbo, Major Idle issue, Microsquirt

[bwalter]

Hello,

This is my first attempt to install a Micro squirt or any stand alone ecu. I currently finished wiring and hooking up my Suzuki 1.6 16 valve engine. The 1.6 is even fire 4 cylinder with MPI. I am using the stock Dizzy which has the built in igniter, cam sensor, and coil. Running basic trigger in ignition settings. Upgraded the B&G firmware to msextra and the engine fired right up first try. I didnt have the Idle control in place so with gentel throttle i was able to keep it running and warm up, it even idled after first start. Super excited at this point! I drove it out of my garage and parked it 50 feet away and shut it off. At ilde it was rich as a pig 9:1, and i thought i would tune it better another day...

However I tried to start the engine again a few days later after upgrading tuner studio and loading some different ve values and I now have a very strange issue, the RPM jumps rapidly by nearly 500, up and down at idle. It almost seems like its missing 2 cylinders. In an effort to trouble shoot this, I ohmed the spark wires all seem ok, replaced spark plugs, and ohmed the injectors. All these seemed with in spec. I retraced all my wiring to the dizzy. With a volt meter on the cam sensor/signal out ( which feeds the ms signal) key on run, I get the square wave 5.6 up and .02 down when I manually rotate the crank with wrench. My dizzy goes to 5v when there is no obstruction and goes to zero or .02 when vain blocks hall sensor. When I was doing this rotating I hear an audible "Click" from I believe the fuel pump relay, I can hear noise in fuel rail. The click happens every other vain on the dizzy. I hear a click on the tail edge of the vain at dizzy when the signal goes to 5volts. If I continue to rotate the crank wheel it will not click on the next cylinder fire or window on the dizzy, but the meter shows 5 volts like it should, if I continue rotating, it clicks on the following window so i get 2 clicks out of 4. I am not sure this is supposed to happen like that, shouldn’t it click after every window? Or should it even click at all? It would seem that the only way the fuel pump relay would click is if it was being grounded for split sec. Maybe micro is doing this? Maybe the cam sensor is shutting off fuel pump relay for brief sec?

The cam sensor I believe is working correctly since I get the 5 volt up and down as rotated, and I get rpm both on my tach in dash and in tuner studio. The igniter built in the dizzy I believe works too since I get some spark... And the coil works since i get rpm on my factory dash and the rpm gauge in tuner studio. Both gauges read the same. The rpm gauge in the dash gets its signal from the coil and the Microsquirt controller gets the signal from the cam sensor out. I installed a 1k pull up for the cam signal as per the instructions, and used the TPSref for 5 volt source.

I did restore the file to when it worked on first start up and it made no difference.

The main relay powers up the Microsquirt controller and the fuel pump relay powers when main relay is on. Fuel pump relay sends power to both banks on the injectors, WB, Idle valve, Igniter, and coil after it is grounded by fuel pump wire from the controller.

I believe this is a hardware issue... but maybe not, like i said earlier, it worked at one time... Maybe the fuel pump relay is the problem? I need to explore how my 12v feed to the cam sensor is wired as i cannot remember 100% if the 12 v power is off the fuel pump relay or the main relay... If it is powered off fuel pump relay, perhaps there is a surge when fuel pump relay is off/not grounded by controller and the TPSref is still providing 5v power???


I attached a log of the engine trying to idle. Maybe you have some ideas based on the log? If I give it throttle is stumbles real bad and pings.

I appreciate the help!

[bwalter]

I believe i finally figured out my issue after all. I didnt notice my afr table was messed up and was extremely lean at idle. Not sure how this happened maybe it was something that changed during the upgrade of software/firmware. I lowered the AFR and the vehicle immediately idled better. Now holding at 1000 rpm steady timing light shows a stobe on all wires and the timing matches the trigger wizzard. I did reroute the power source for the cam sensor from 5 v tpsref to a switched 12 volt supply. The Cam sensor now works opposite. Now when a window is present in front of the hall sensor the signal is grounded and when a shutter is blocking sensor it goes to 5 v

Thanks to everyone for looking. Will attempt another warm up tomorrow and see if my changes in tune will continue to allow the engine to start and idle. I think the bottom line was i am way too new ( and ignorant/stupid) and the learning curve is steep!

[iambiker67]

I earlier issue with the fuel pump on my Suzuki GSXR 150. It was left unridden for a long time and then the problem started. My 2018 GSX-R150 use to have a very bad throttle input took it to the service station and found out that my fuel pump was jammed. replaced the fuel pump and now it's working fine.