My 98 Mazda 626 GF 2L won't start. About a week ago I was playing with the air adjust screw ( taking it from full open to almost closed ) and it wouldn't start after that, so I assumed that was the problem, reopened it and after a few tries and waiting a bit it started and ran for ten minutes before I shut it off.
After a week, tried starting it again. It started ran for a second or two, then died. Started it again and tried giving it gas, same thing happened. Now I can't get it to start at all. Thought I might be getting too much water condensing in the tank since it's been sitting with an almost empty tank in hot weather for quite a while, so I put in some IPA and an extra four liters of gas, but that so far hasn't helped. Hope I don't have water in the fuel line.
It reminds me of what happened when I disconnected the fuel pump on a different vehicle once to depressurize the fuel line before changing the fuel filter.
So I hooked up a scan tool while trying to crank it. I looked at the live PIDs while trying to crank the engine and the only ones which stood out as looking unusual where:
Short term fuel % trim - Bank 1: -100%
Absolute throttle position: 10.98% ---- Min=Avg=Max
Calculated Load got up to 85% while cranking.
Just for reference to the Freeze Frame later on:
Engine coolant temperature: 80.6F
Intake air temperature: 102.2F
Long term fuel % trim - Bank 1: 0
There are also three stored DTC's, two pending ones and a freeze frame ( which I assume is related to the most recently occurring DTC ).
P0113: Intake Air Temperature Sensor 1 Circuit High
P0118: Engine Coolant Temperature Circuit High
P1409: Mazda: Electronic vacuum regulator control - circuit malfunction
P0122: Throttle/Pedal Position Sensor/Switch "A" Circuit Low
P1131: Mazda: Heated oxygen sensor (HO2S) lean mixture indicated
Freeze Frame ( Can there be more than one freeze frame? )
DTC: P0118 Fuel system status: Open-loop due to insufficient engine temperature Calculated load value: 15.29% Engine coolant temperature: -40F Short term fuel % trim - Bank 1: 24.22% Long term fuel % trim - Bank 1: 0 Engine RPM: 2544.5 Vehicle speed: 0
I verified there is a small vacuum leak from the number 3 lower injector seal, but it's not new and I don't think it's the cause of this problem.
Coolant temp sensor was disconnected for a while while locating a coolant leak, and I've also started the engine with some vacuum lines disconnected once or twice.
The only things I don't think I can explain away are the TPS reading and the short term fuel trim. I'm not sure about why the load got so high during cranking and if that's normal or not.
I took the throttle body off and cleaned it a few weeks ago, and last time I looked it was fully closing, although I guess it's possible it recently got stuck open a bit somehow.
Should I try resetting the ECU or clearing all codes and trying again to see what happens?
What should my next step be?
After resetting all the DTCs the P1409 code went from stored to pending, and I still can't start the engine. I hooked up the ForScan software which gives access to the ECU built in self tests and ran all I could. Another code came up,
P1624 - Immobilizer communication count = 0, but I think that's OK as the previous owner disabled the immobilizer. Other than those two dtc's everything supported came up normal including the fuel system.
For P1409 Forscan shows ( EVR = Electronic Vacuum Regulator ):
===PCM DTC P1409=== Code: P1409 - EVR circuit fault Module: Powertrain Control Module Diagnostic Trouble Code details EVR circuit fault This DTC may be caused by : Suspect EVR solenoid. Open EVR circuit. Shorted EVR circuit. Shorted EVR wiring harness. Suspect PCM. ===END PCM DTC P1409===
I wonder if this has anything to do with my recent Seafoaming of the intake. I've heard this can uncover problems with the EGR, although I'm not sure how.
Maybe the EGR is stuck open and that's why it won't start?
Turned out the EGR solinoid was just unplugged, so I plugged it back in, but it still won't start and now when I try to connect to the ECU it fails with CAN ERROR: 3 ( 8.1% ), whatever that means.