Idle Problems

SON240sx Automotive
1

Previously, my CA would idle at about 700rpm when cold, and the idle was very lumpy. I assumed this was because of shitty old gas and a faulty temp sensor. My CA MAFS was also sending back 11v.

I put the ECU in diagnostic mode, and did not make note of where the pot was to begin with, and got a code for MAFS and Coolant Temp Sensor.

I swapped the MAFS (SOHC KA) and turned the ECU pot all the way counter clockwise.

I tried to start it up again and it wouldn’t go. Unplugged the battery for 30 seconds, and gave it another try. It would catch slighty, and sometimes run for a few seconds, then die. Most of the time I’d have to help the motor along with the starter after it was catching to get it going, and then it would only run at 500rpm. Touch the gas and it would die right away.

Then I swapped the coolant sensor and there was no change.

I haven’t been able to get the motor idling long enough to check the MAF voltage.

It must be getting fuel and spark, since it does sort of run… no way to check vac, but again it was running previously and stable at 700rpm.

Any ideas?

2

Unplug the maf and see if it will start in limp mode. Check the maf wiring as well to make sure you don’t have a short of some sort… 11v from the maf sounds pretty fishy to me.

3

I tried both those things… the motor runs the same with or without the MAF.

I also checked the MAF wires for shorts to ground, and there was nothing; it’s the same at the MAFS side and the ECU side.

4

Check the fuel presure and the spark with a timing light…