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Tofuball's '94 XFi; It's all about city MPG
Topic Started: Mar 12 2011, 08:59 AM (39,436 Views)
ponzy


nice tofu, i believe you have upgraded to an efi instead of the tbi? or there are some 3 cyl that run on with efi? or you just swapped in the TB/intake manifold/fuel rail?
Edited by ponzy, May 11 2011, 01:59 PM.
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Tofuball
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Strange Mechanic

I haven't actually DONE anything yet, I just made all the parts and have them ready.
The car comes from the factory EFI, TBI = EFI
I'm just going from TBI (One injector) to SPFI (Sequential Port Fuel Injection, three injectors) and using a log style intake manifold.
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nerys
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Grr

he meant MPFI :-) never heard of SPFI whats the difference?
Edited by nerys, May 12 2011, 07:27 AM.
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Tofuball
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Strange Mechanic

TBI => (Throttle Body Injection) has a single injector above the throttle plate.

MPI\MPFI => (MultiPort Fuel Injection) implies batch injection (All fire at once, stock on the multi-injector swifts) The injectors are almost always as close to the intake port as possible.

SPFI => (Sequential Port Fuel Injection) implies sequential injection, each injector is tuned to fire at exactly the right time. The injectors are almost always as close to the intake port as possible.*

They are all forms of EFI.




*The RX-7's secondary injectors are a notable exception - located farther up the intake stream with large fuel diffusers right in the intake track to help mix the fuel in with the intake charge, and using the intake runner to "mix" it. I believe this is necessary due to the inferior design of the injectors of that era. They kick in at 3800RPM. I found a workaround that took advantage of calculating the airflow above 3800RPM and cutting the intake in such a way as to form a vortex right in front of the injector. Worked up till about 9KRPM, then I had other problems to deal with (such as running out of air and ignition breakup), so I never bothered to recut it :P
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Tofuball
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Still crazy busy. No progress to report :(
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econoboxer
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I am the one on the left.

lets hope you find the time to get it done, looking forward to see how well this goes for you.
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Tofuball
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So tired. I've worked on everyone's car but my own.
Got a bunch of job prospects but nothing concrete. I got too comfortable at my current job and let the new technology get away from me.

Anyway you want to hear about the car.

I got the exhaust complete. No leaks, doesn't hit the body anywhere. Weighs less then stock. Magnaflow muffler. I'll post pictures if you really want but the whole system is pretty hacked, I didn't have time, just wanted it done. It is straight through the whole way, you could cram a garden hose in the muffler and it would hit the exhaust valve. Sounds real nice at idle, bit louder then I'd like -- but I haven't put a tip on it yet. Very base-y. It's enough to make people wonder what is under the hood, until it starts moving at least, then it sounds a bit ricer-ish, but no farting at least. I'm hoping it'll get better when I fix the timing issue.

Haven't pulled the timing assy apart yet, I plan to do that at 1 today but my life is so insane who knows if that'll ever happen. ;)

If the system is too loud or drones, I'll add another flat magnaflow in the front. I would recommend anyone doing this use a pipe size between 2 inch and 2.25 inch, the stuff I had was 2.75 and it's way too big - part of the reason for the part of the exhaust tone I don't like, and the increased volume. Keep in mind it's not really that loud, just louder then _I_ would like.

A reducer after the muffler, then an exhaust tip that points down, should help.
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Bad Bent
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Facetious Educated Donkey

The exhaust tip helped a little on mine to get the sound waves out beyond the bumper. You might have to redirect yours differently.. :hmm But I get looks and comments also from people who don't believe it's just a 3 cylinder Geo. :lol

Yes, life is getting more and more crazy. Like the song goes "workin' 3 jobs just to stay in debt..."
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Tofuball
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Posted Image
The Honda engine, stamped "PR4Y."

Posted Image
The issue with my car. I can hear some of you guys saying "I told you so!"
Well, you're right!

Posted Image
ARGHHHH

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Anyone selling the main pulley gear? :)

What did I do that caused this?? I've never even seen anything like this before.

That's depressing, I really didn't want to have to pull this engine apart, such great compression :(

So I figure I'm stuck with either measuring real close and drilling three new holes through the whole gear and into the crank and then tapping them and driving some bolts in, getting a new crank, or just putting a new key\gear in with some JB weld . . .
Edited by Tofuball, May 28 2011, 03:17 PM.
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mcmancuso
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Its unfortunately pretty common. Typically cause by either, the crank bolt working itself loose as it came from the factory, or it was under tightened by someone who worked on it in the past. You can re-key the pulley and crank 180° off from the original position, or grab a new key and put some JB weld on there and hope. Really, the key is not what is supposed to hold it in place, its the proper torque on the bolt which should do most of the work.
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nerys
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Grr

a machinist might be able to weld and then "recut" that slot ??? or you already have it out just replace that gear. the "shaft" side looks ok.
Edited by nerys, May 28 2011, 11:00 PM.
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Tofuball
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They could, means I'd have to pull the crank.
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snowfish
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Basic GearHead

My vote is to JB it with a new key. :thumb Torque 'er to 81ftlbs and let it buck! :drivin Can't break it any more. :tumbleweed I bet it will hold just fine. :cheers
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Tofuball
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When the industrial tool place opens up I plan to purchase three allen-head set screws, a tap, and a few cobalt drill bits.

Then I'll have some alone time with the gear and it will be changed forever.
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ubookz
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[ *  * ]
I have read this thread all the way through...very interesting! I am a low tech type of diy, but am allways open to progress. What caught my attention was the aspect of warming up incoming fuel to the tbi; I wonder if anyone has tried this? :hmm :drool
Edited by ubookz, May 29 2011, 05:02 PM.
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