Random stalling

cre · 04-04-2012, 01:47 AM

Bypass the fuel pump resistor pack and relay, look at the TEWD for wiring info.

You've inspected and tested both TPS and ISCV, correct?

Did you test the VAFM in the manner I described? Is the FC switch showing a ground signal when the vane is open?

Turn the ignition on (not the engine) and unplug the VAFM. This will set codes 24 and 32 in the ECU. Turn the ignition off and then back on and wait a minute to be sure. Now turn the ignition off and set the diagnostic jumper... check for codes, if there are any then the ECU isn't losing power when the ignition is off and the diagnostic functions are operational. Don't reset them yet.... Go for a drive or run the car until it dies, now check for additional codes making sure that the 24 and 32 are still present. If they're still there but there's nothing new this negates the possibility of a problem with the EFI relay, the circuit opening relay and makes for a huge argument against the ECU being damaged and not storing codes.

I don't know if you're being selective about what you're testing, you're just not giving results of all the tests prescribed or I'm missing them but read back through and if there are any tests you've neglected then do them.

What was the cause of the error code 41 you originally reported and what did you do to remedy it? That's indicative of a TPS failure and may cause significant issues when transitioning to idle.

Sorry if some of this is repetitive but this thread's getting a bit long for me to keep reading and I don't recall some things being tried or answered.

Voltage drop with the headlights and heater on isn't uncommon.... old wiring, weathered grounds and a VERY small alternator are to blame. The ECU won't even hiccup until the voltage is a couple tenths below 11v.

EDIT: I have been through this with a N/A MKIII before. It was the AFM in my case but only when hot.... I found it by testing components with a hair dryer one by one. I had no diagnostic codes being stored either.

04-04-2012, 01:47 AM	#38
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Bypass the fuel pump resistor pack and relay, look at the TEWD for wiring info. You've inspected and tested both TPS and ISCV, correct? Did you test the VAFM in the manner I described? Is the FC switch showing a ground signal when the vane is open? Turn the ignition on (not the engine) and unplug the VAFM. This will set codes 24 and 32 in the ECU. Turn the ignition off and then back on and wait a minute to be sure. Now turn the ignition off and set the diagnostic jumper... check for codes, if there are any then the ECU isn't losing power when the ignition is off and the diagnostic functions are operational. Don't reset them yet.... Go for a drive or run the car until it dies, now check for additional codes making sure that the 24 and 32 are still present. If they're still there but there's nothing new this negates the possibility of a problem with the EFI relay, the circuit opening relay and makes for a huge argument against the ECU being damaged and not storing codes. I don't know if you're being selective about what you're testing, you're just not giving results of all the tests prescribed or I'm missing them but read back through and if there are any tests you've neglected then do them. What was the cause of the error code 41 you originally reported and what did you do to remedy it? That's indicative of a TPS failure and may cause significant issues when transitioning to idle. Sorry if some of this is repetitive but this thread's getting a bit long for me to keep reading and I don't recall some things being tried or answered. Voltage drop with the headlights and heater on isn't uncommon.... old wiring, weathered grounds and a VERY small alternator are to blame. The ECU won't even hiccup until the voltage is a couple tenths below 11v. EDIT: I have been through this with a N/A MKIII before. It was the AFM in my case but only when hot.... I found it by testing components with a hair dryer one by one. I had no diagnostic codes being stored either. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 04-04-2012 at 01:51 AM.