It has been a long time since updated this blog.
I decided to add this post as I encountered hard start with my engine for the past one month.
The car was driving fine for years and months, without any symptoms of any failure. I drove to work and after I park my car for 8 hours, she decided not to start. Prior to this nothing was added or done to the car.
There was good cranking, fuel and spark. Timing was ok. I changed my distributor to be sure (OEM original rebuilt by myself with new ICM and Coil), still no start. I decided to get it towed to my workshop, obviously it is out of capabilities.
My mechanic/tuner did the same checks but couldn't find any mechanical fault. He decided to reload the tune (Hondata S300) and the engine managed to start. Yeah! Problem solved! BUT nope, the subsequent few days, she was temperamental. Sometimes, she will start right up and sometimes, I did crank until the plugs get wet with fuel... So I had to remove the plugs and let the cylinders dry up of fuel. The next day, after putting the plugs, it will start right up.
So I thot maybe the injectors are leaking and there is too much fuel in the cylinders or I need to reduce the cranking fuel injected, since the AFR was reading richer than normal compared to before immediately after start up (I am running ID1050X, which was starting and idling perfectly). For days, I tried different tunes, playing with the fuel trim in Smanager for cranking, but she remains temperamental.
To be clear, when she starts up, she drives and idle perfectly. No signs of any issue at all; I have my PLX AFR meter, my laptop connected to check for any abnormality.
One day, I notice my AEM Fuel Pressure Regulator is leaking again! (The first I got which lasted for over 15 years leaked and I replaced a new one 6 months ago) I replaced it with a Sard Fuel Regulator. Then she start immediately! Hey I found the fault! NOPE! The next day, the hard start returns again.
Running out of ideas, I decided to clean my IACV. It was quite dirty but that didn't help. Then I notice my IACV wasn't running (usually, there is a slight buzz if I put my ear next to my intake). But even so, I thot the engine so be able to start even with a faulty IACV. I checked my idle screw on my throttle body, it was screw all the way in tight!
What happened was that the IACV was doing all the work of letting air in during cranking all this time! Once the IACV decides not to work, the engine was not getting any air at all, thus the rich AFR reading if she starts or doesn't start at all.
So now, before my IACV replacement arrives from japan. I open my idle screw out and let the engine idle at 1200rpm. At this setting, the car can start even if the IACV is not working. If I turn the idle screw to lower the rpm, I will not be able to start the car if the IACV decides not to work.
Hopefully, this post will be useful to those facing the same problem. I have been searching for answers for the past one month and wasn't able to get any solution or any hint that IACV can cause the engine not to start.
The IACV will open up when the key is turn to "on" (position before cranking) to allow more air to enter into the engine during cranking. It is not just solely to control the idling the engine.
No comments:
Post a Comment