Car starts now, runs for a bit, dies seemingly randomly?

matt_fulghum · Post by **matt_fulghum** » Wed Jun 21, 2006 11:27 am

I got my car running, albeit at a very high idle speed (no idle controller hooked up). It ran for quite a while, and I started screwing in the idle screw to try and slow it down but it eventually died... Someone wanna look at it for me?

'92 Mazda MX-3
'93 Protege LX engine. 1.8L Mazda BP
overbored to 1.93L, compression cranked to about 11.5:1
450cc DSM injectors, running 35% PWM (I'm pretty sure)
MS alpha code... 2.672x7B to be precise.
MT 2.25

Log attached. I'll grab the MSQ too if anyone wants to see it.

I'm wondering if the sudden drop in the ignition advance table I've got upset things?

matt_fulghum · Post by **matt_fulghum** » Thu Jun 22, 2006 7:17 am

anyone?

Mike Simard · Post by **Mike Simard** » Thu Jun 22, 2006 7:34 am

It looked like you could have started to get too lean as you dropped the idle speed. Those are big injectors, maybe your lowest idle ve bins should be richened up until you get the PWM and lag times dialed in. Also, drop that 2.672b code and get the new 2.683. Are you sure your advance on the car matches with a timing light? The advance could be too low but it should have stayed running as long as it was getting fuel. You're close!

matt_fulghum · Post by **matt_fulghum** » Thu Jun 22, 2006 7:42 am

I ran the car again without incident and nary a stumble yesterday, and without touching it or anything it died again... I'm wondering if I've got a bad ground or something and one of those fuses on the relay board or the MS itself is getting too hot and shutting off

mops · Post by **mops** » Thu Jun 22, 2006 12:51 pm

I have sort of similar problem.

on stone cold engine.
I crank and start it up. runs for few seconds (5-10 seconds) then idle speed comes down and it dies withing next 2 seconds. warmup enrichment already at 140% and it's rich I can smell petrol in garage and stuff.

does it only sometimes....

matt_fulghum · Post by **matt_fulghum** » Thu Jun 22, 2006 1:14 pm

except in my case it just dies. The idle speed doesn't drop or anything. The only reason the idle speed dropped in the log I posted was because I went out and closed the screw a bit.

*sigh* oh, and I managed to fry my LC-1 when I knocked a 12V wire off my power terminal block onto the grounding wires of the wideband yesterday, when I installed my fan. Fun.

matt_fulghum · Post by **matt_fulghum** » Mon Jun 26, 2006 2:40 pm

alright, the car's starting more easily, still idles very high, but I'll fix that when I figure out why my car sorta just dies. It's doing it less I've noticed.... anyway, logs + msq.

I set up the ignition table to be 14 BTDC ~idle, and 10 otherwise, a pretty much flat map, just till I get idle sorted.

I found another problem too... one of my heater hoses is leaking at higher coolant temps. Lame. I was wondering where that coolant was going (:lol:) gotta fix that before I do much else.

In my second map there was a real stumble near right before I turned the engine off... I wonder if it was because the coolant was going crazy?

Also, for some reason my radiator fan, which I have set to turn on at 160 just to be safe, turned off around 164, and didn't turn back on. I have it running with its ground going through the FIdle relay... Could someone check if my spare port setup is weird? I don't see why it would be....