View Single Post
Old 11-24-2010, 07:38 AM  
Poolside OP
Syndicated
 
Poolside's Avatar
 
Joined: Apr 2003
Location: Long Beach, CA
Oddometer: 11,660

When I posted that data acquisition picture, the picture with the stuff on the tank, I didn't want you guys to think that was how complicated it is. That is the development and research setup I use to figure out all of this stuff.


You guys are right though, it isn't pistons and cams. You can go ahead and make those mechanical improvements. But without making changes to how the ECU delivers fuel and spark, the drivability issues will remain, and in many cases they get worse.

At this time there's four products in the works. Following posts are an explanation of the first two products, since they are close to being finished.

I'm sure most of you have a basic understanding of how EFI works. The ECU reads the sensors, air temp and oil temp for example, looks at the motor RPM, checks how far the throttle is open, and injects the right amount of fuel.

This is important:
The air temperature controls the 'open loop fuel mixture'.
The oil temperature controls the 'accelerator pump' feature.

"What do you mean by open loop fuel mixture?"
Here's what I mean. The fuel injection computer reads the air temperature and air pressure, and computes the 'weight' of the air. Then, based on the RPM and how far the throttle is open, it computes how much air is going into the motor. Finally, it squirts the right 'weight' of fuel into the motor to make the right air fuel ratio. For example, the familiar 14.7:1 by weight ratio.

"What do you mean by 'accelerator pump' feature?"
Here's what I mean. I'm pretty sure you understand that Electronic Fuel Injection systems do not have a mechanical accelerator pump like a carburetor. But, EFI does have the 'electronic equivalent' of an accelerator pump.

This bears repeating.
The air temperature controls the open loop fuel mixture.
The oil temperature controls the 'accelerator pump' feature.


__________________

IICE Air Hotrod your GS  Fuel Injection  Tech Info  Buy  Order List  Installation
Poolside is offline