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Installed my FAS switch on the Insight this afternoon, and I tried to do it using one wire, still in the cabin.

I'm interrupting the power going to the injectors from the connector next to the ECU.

The problem is, this power goes to the injectors AND the IAC (Idle air control) valve. The ECU figures out the IAC lost power pretty quick and throws a CEL.

However, it works, and the CEL doesn't affect anything, it's just a warning code.

Looks like the 3 wire injector cut is the only way to go. :)

I'm amazed how long it takes the engine to spin down once it loses fuel - that IMA motor must be one brick of a flywheel.

I was worried the CEL would throw the ECU into Limp mode, and you'd give up timing and overall FE of the ICE, so watch that. I believe even if you do the three wire trick, it will still throw a CEL. The ecu will see the circuits open and won't like that. When the ECU is trying to squirt fuel, and the o2 sensor tells it there is no fuel it won't like that either, and it'll know somebody has been installing FAS switches. I suppose it is easily and quickly reset with the sg though.

Hi Shifty35:

___Randall (Highwater) installed his FAS switch with a 3 pole solenoid for all 3 injector wires with one control wire and a ground (IIRC???) back to the switch on the shifter in the cabin. His would not throw a cel and did interrupt and shut down the ICE immediately without issue.

___Send him a PM but I believe he had a nice write-up on the HW, connections and features in a How To about a year ago here at CleanMPG.

___Good Luck

___Wayne

I am not aware of any of the Insight FAS mods that are having codes thrown.
I need to take an updated pic of the dash display during an Insight safeFAS.
The latest upgrade to that mod has no pesky warning lights during ICE off time. Just a nice clean display, like the ICE was running. The version one FAS switch mod had a trial-by-fire of sorts, during the Insight marathon.

Randall

link to fas mod thread
http://www.cleanmpg.com/forums/technical/t-fas-mod-on-my-insight-2563.html

I'm not throwing any codes with my MIMA/FAS install but I swear my car is making a funny noise now. Sounds like a very quiet diesel at times. Mike mentioned that you had injector problems with your initial install of FAS. Were there codes set when you were running on 2 cylinders?

Then again it could all be in my head or the fact that I'm still running without the shifter console not installed back yet is allowing more sound that I'm used to hearing in. Or maybe my HAI is rattling against the battery box.... who knows what it is but I'm not setting codes so I guess its not that big a deal ;)


I really want to rig up a way that when I hit my FAS button it kills the Power steering as well. Shifty has talked about how to do it, but alas I'm a wiring newb so someone would really have to show me. I'll figure it all out once my HID's get here and installed and I finally finish up installing the 4 different projects I've got going on all at once in my car.

April/May of this year. I had an issue with one of my solder connections on the original (pre plug-n-play version) wiring of one of the injector cuts. That will give you a cylinder misfire code, and I don't recall what that code is at the moment. When I finally figured it out, I replaced my solder connections with the nice tele-com silicone filled crimp connectors, on all three cuts.

Blake, the extra noise is probably the console being off IMHO. Been there.

Randall

Update -

The CEL only gets set it you accidentally leave the switch on when the engine tries to engage the IAC. It seems to clear itself after a couple drive cycles if you use it correctly.

It does kill the engine immediately, but when you are at 3k rpm or higher, the engine still takes a couple seconds to wind down, and it seems to do so rather slowly for such a small engine. Chalk that up to the extremely low valvetrain losses and the weight of the IMA motor acting as a very-heavy flywheel, in addition to the actual flywheel.

Still, I guess it demonstrates that cutting the power to the injectors is just effective as cutting the ECU ground for them. But I'll be switching over to the relay method, I've got the 4 poles sitting around. Just wanted to see if this worked. ;)

i have been using the "kill the power to the fuel pump at the fuse block" FAS method for two years now. no CELs at all. i do have a dual relay rig ready to install to kill the injectors, just waiting for the time and weather to mesh.

I got a call today about FAS.
They have a CVT Insight, and want to know if the FAS relay system will work.
Of course the CVT has no clutch or neutral switch like the 5 speeds, so that part is not necessary.
Any CVT insight drivers played with an FAS switch?

The key to FAS with no codes is to use a momentary switch, so the injectors are reconnected as soon as the engine cuts out.
;)

Could then go to neutral and FAS at the same time? The CVT
*does* have a true disengaged neutral, right?
.
_H*

Hi Al:

___Except there is a belt flopping around the now opened up sheaves … Kind of neutral but there is some drag in there somewhere unfortunately :(

___Good Luck

___Wayne

PWM drive circuits to motors and solenoids typically have diodes to prevent excessive voltages when suddenly opening the circuit. Should that be a consideration in the design of FAS circuits?

There are diodes in the (Insight 5sp specific) relay FAS mod found on Mike's page here (http://www.99mpg.com/Data/Resources/downloads/relateddocuments/total_fas.pdf).

Randall

Yes it does, but my question is if you put the CVT in neutral, and cut the injectors to cause FAS, will the engine stay off when the injectors are reconnected, will it restart when you shift back to drive, or deplete the brake vacuum, or step on the gas like the 5 speed?
My CVT on a stand is not at a stage where I could test that, so I was wondering if any of the CVT drivers has tried to do a FAS modification.

I'd expect this approach to work when coming to a stop / stopped in a CVT.

However, when rolling at 25+, I'd expect the IMA to attempt to restart a "stalled" engine. We 5spd drivers hold the clutch in to prevent this restart behavior, but there is no analogous IMA prevention mechanism in a CVT.