can I change my EFI to CFI?
08-19-2003, 03:16 PM
#1
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Join Date: Apr 2003
Location: idaho
Posts: 44
can I change my EFI to CFI?
I'm having trouble with my stock '82. I need to know if I can hardwire my TPS directly to the six injectors and just have CFI? I'm going to have to replace my entire harness, but I was figuring that maybe I could just scrap the whole thing and have the injectors directly run by the TPS. That would make my life a whole lot easier.
Would I run into a richness problem if I rigged it for CFI? I dont think it will effect a stock L28n/a too terribly much, but any ideas or advice would still be a great help.
Would I run into a richness problem if I rigged it for CFI? I dont think it will effect a stock L28n/a too terribly much, but any ideas or advice would still be a great help.
08-20-2003, 07:34 AM
#3
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,296
I really have no idea what you are trying to do. I don't think the computer works like that. It reads the air flow meter, head temp sensor, and throttle position switch to meter the fuel. It would take some thinking to rig the computer to work only with one sensor.
If its that bad, make yourself a MegaSquirt computer and new wiring harness. Screw in a couple GM sensors and rid yourself of the AFM!
http://www.bgsoflex.com/megasquirt.html
Don't forget to check out the MegaSquirt Yahoo group if you do build it. Lots of people to help out.
If its that bad, make yourself a MegaSquirt computer and new wiring harness. Screw in a couple GM sensors and rid yourself of the AFM!
http://www.bgsoflex.com/megasquirt.html
Don't forget to check out the MegaSquirt Yahoo group if you do build it. Lots of people to help out.
08-20-2003, 09:43 AM
#4
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Join Date: Apr 2003
Location: idaho
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see, what I'm trying to do is scrap the computer. I want to wire all of the injectors to the tps and use it to provide the current to pull back the needles. However, the only way I could think of to make it work is that it would constantly fire all six of the injectors. when I hit the gas pedal, it would suck that switch back into the intake, providing more current, opening the injectors further.
On the megasquirt: I was looking at that a while back, and I was wondering HOW, exactly am I supposed to put GM parts on my Datsun? that seems like it would be a little difficult. AND I'm not sure that my caveman laptop even has a serial or USB port.
I heard about this intake manifold I can buy... I forget the name of the company... but It's supposed to be a bare bones dual carb system (Like the 1stgen Z's) that will let me toss all the wiring harness and all those spaghetti lookin vaccuum lines.
On the megasquirt: I was looking at that a while back, and I was wondering HOW, exactly am I supposed to put GM parts on my Datsun? that seems like it would be a little difficult. AND I'm not sure that my caveman laptop even has a serial or USB port.
I heard about this intake manifold I can buy... I forget the name of the company... but It's supposed to be a bare bones dual carb system (Like the 1stgen Z's) that will let me toss all the wiring harness and all those spaghetti lookin vaccuum lines.
08-22-2003, 04:43 AM
#5
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Join Date: Jul 2002
Location: Sweden
Posts: 71
I don´t think that it can be done youll need a control unit for the injectors and that is located in the ECU. Even if you got it to work you would loose ecu features like "acceleration enrichment" and risk going too lean when you´d need the extra fuel to cool your engine.
08-22-2003, 12:10 PM
#6
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,296
Ya, you might as well slap on dual SU's from what you're talking about.... you'd probably much better performance than firing all those injectors all the time.
Or convert to throttle body injection like cheap american cars from the 80's.
Or convert to throttle body injection like cheap american cars from the 80's.
08-29-2003, 08:18 AM
#7
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Posts: n/a
It sounds like he wants to do something like what VW did with their CIS (constant injection system) by Bosch. This was mechanical fuel injection that had a metering plate that when vaacum from the engine pulled the plate up a measured amount of fuel was batch fired into the engine. I think that rigging up something off the TPS would prove to be difficult for a couple of reasons one of them being cold starting. You would probably have to add 7th injector to richen the mixture when it's cold. Also how would you tune the engine?
Think about this as well, fuel isn't prpoportionate to throttle angle a certain amount of fuel must be added for a corresponding amount of air entering the engine. How do you plan on compensating for that?
I'm not shooting down your idea but I am curious.
Think about this as well, fuel isn't prpoportionate to throttle angle a certain amount of fuel must be added for a corresponding amount of air entering the engine. How do you plan on compensating for that?
I'm not shooting down your idea but I am curious.
08-29-2003, 08:52 AM
#8
if you try to put cfs in a z you are in for a world of trouble. first of all you would burn your valves to a crisp in no time. second you will run the risk of possible backfire through your fuel tree and that could in burn your whole car to a crisp. your best bet is to get a stand alone fuel management system
09-02-2003, 06:19 AM
#9
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Join Date: Apr 2003
Location: idaho
Posts: 44
see? That's why I ask. I wanted a second or third or fourrth opinion before I jumped right in. I appreciate all the feedback and I've decided on a hybrid. I've even narrowed down my choice of engine to a ford 302 or a dodge 340. Thanks a lot yall.
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