DIYPNP first start unsuccesful
 

I finally got time to wrap up installing my first MS, and unfortunately, I couldn't get the car to start. I've attached my map & a short log (~5 sec of cranking). Maybe someone can spot something obvious that I've done wrong?


1991 1.6 naturally aspirated
DIYPNP (v1.5B/v2.2M)
GM IAT MAF delete
LC-2/LMU4.9
disconnected OEM non-VTPS


I removed the 10A pump fuse before starting the 1st time, but didn't realize I needed to pull the TPS pigtail. OK, OK, mistakes were made. pigtail is disconnected now. I let the car sit for a couple hours, and still no dice.


this is absolutely my very first time trying to do this, so... well... flame on.

:noob:

Fix your CLT readings - it's stuck at 0.1 degrees.

Thanks! I recall that while bench testing it, the CLT gauge was sitting at ~0, but would spike momentarily at regular intervals. This being my first MS experience, I didn't know if that was normal behavior or not with the MS not receiving CLT sensor input. I guess I got so used to seeing it behave that way, I didn't notice that it was still acting the same when plugged into the car. I'll crack open the box tonight & see if there are any obvious cold sockets or flux bridges. Does anyone have a schematic or component checklist specific to the CLT circuit?

did you calibrate it?

Yep- calibrated per the tables published along with the jumper table for 9093 miatas

I had the same problem when i installed the DIYPNP. Are you positive you've got the resistors on the CLT line?

Ah ha! CLT jumpered to 4O instead of 4Q. Easy enough to fix.

resistors on the CLT line???

The only resistor I put in with the jumpers was on the TPS SIG --> GND jumper, because I'm still running an OEM non-VTPS.

I should get another chance to test things out this afternoon.

thanks again for the assist guys, it's really been a huge help

LOL I have no idea why I worded it like that.


I had a similar problem when I was missing a CLT bias resistor.

we are talking about the DIYPNP...

success! took some doing, but the car started & ran. Idle is pretty high though (~2700). here's the first log of it running.

first conspiracy theory to test in the morning: looks like my PWM idle DC is about ~14% higher in the log than the values I input into my map for given temps. Now I never built the complete AC circuit in the MS because I gutted the AC system from the car. However, I noticed that the AC idle-up in tunerstudio is set to on, and that the DC % adder is 12.9%. I'm gonna shut off the AC idle-up & see if it helps bring my idle down to a sane RPM.

I got the idle running correctly. I turned off the AC idle up (not sure if that did squat), switched the idle control valve mode from inverted to normal, and changed the valve freq from 480 to 279 hz. kind of an unscientific shotgun approach- did them all at once, but it gave me a great start & warm up to temp. I got the base timing set with the trigger wizard. Now on to VE & warm up auto tuning. Then closed loop idle... VTPS... seq inj...

why were your idle settings that way in the first place?

The settings were that way on the base map I used, and I'm just learning how all this works. Yesterday I set the idle valve freq to 340 (2x170), & did about 45 minutes of auto tuning.

The car starts & warms up pretty nicely, but idles low (~600) at operating temp. Today I'm going to turn on & experiment with idle advance.

im just trying to figure out why any basemap would have those settings...

Dunno. Could have gone nutter after updating it to the current firmware version?

I used the 3.3.1a 90-93 map from here:

MegaSquirtPNP by DIYAutoTune.com

Bumped up idle pwm % by 2% for the upper temp range in the idle warm up duty cycle, and it's idling nicely at operating temp now. Not sure if that's kosher, but it's working.