Running TPI without computer
 

Have any of you ever heard of anything like this? I was thinking about it the other day, and wounderd if it would be something possible to do..?

I would think its impossibe.

Uh, yeah. Pretty much impossible.

Not 100% impossible, VW CIS-E can run without the computer, they just run bad. ;)

Of course, they dont need injector pulses to fire.

I guess you could run some wires to a push button switch in the cockpit and push it every time you want to use your injectors! :D

i was thinking something a little different, like wiring the injecters with the distributor, but like 1 or 2 cylinders before it would fire (so it has some time to spray) and run it thru a timer as well, so you could adjust how long it sprays. hmm, ideas are brewing :D

Why would you want to, though?

"i was thinking something a little different, like wiring the injecters with the distributor, but like 1 or 2 cylinders before it would fire (so it has some time to spray) and run it thru a timer as well, so you could adjust how long it sprays. hmm, ideas are brewing " QUOTE


Gee...I am pretty sure they already make such a beast...it is called THE COMPUTER

:p

The ECM does use the dizzy reference pulse to fire the injectors and it has a built-in timer to adjust pulsewidth...So...Lucky you, your project was already designed and built by a little company we shall call GM :D

A 2v sidedraft carb, like a sidedraft Weber, mounted in place of the throttle body, would run, but it would have all the minor pronblems associated with carbs and tuning, nevermind that you'd be running wet flow thru the TP runners so I would expect fuel distribution to be poor.

But it could be made to work, and run.

Lets just say NO you cant. Why would you get rid of the computer? Want FI without the ECM? Go find some guy wanting to get rid of his 58 Fuelie Corvette.

well, i'm hoping to do it with out the computer cause i don't like them.. and i want to beable to change pretty much anything i want with out reprograming or burning chips.

Get a carb.

Yeah, dude, you just described a carb system. You dont have to fool with the computer, you can do all the tuning with the carb and the distributor, and you'll flow more air. Seriously, it just doesnt make sense.

Even if you were able to wire up something to the distributor to fire the injectors, you would need something to increase or decrease the pulse width. You would then need a NON computer controlled distributor. Then you would need to figure out a way to compensate for load. Oh wait, you can't really do that without the computer. I guess you could design a switch board made up of resistors, relays, and switches to do everything that a computer does, but then you still have to tune it. Not to mention the nightmare of trying to phase everything to work properly.

Go for the carb best solution for ya...

I have a somewhat interesting question for all of you...I know this isnt really F-body related but the split-window corvette was fuel injected right? the corvette that Im talking about was only made one year...cant remember which year it was..... did it have a computer????

Dan

Look, it IS possible to do it, its just so insanely difficult that its not worth it. And I guarantee you, anything you can "fab" up is never going to beat the computer when it comes to doing the job right. This discussion is pointless. If he doesnt want a computer, he should get a carb or a bicycle. Those are his only real options.

right now i have a carb, and a non-cc dist.
also have all the parts for a TPI system without the injectors or comp... i like how i can mess with the carb when ever i want, but the same amount of fuel never gets to all the cylinders. with the TPI deal i want to rig up i'd be able to set how much fuel gets sent to each cylinder, when its gets sent and beable to adjust any part of it by basicly turning a knob. see what i'm getting at now?

dude... look... if you dont want to toy around with computers, then dont go FI. Want FI, get a C1 with a fuelie in it ok? You cant just adjust knobs and all this to have a good running FI system. You can tune the fuel presure with an AFPR, you can hook a laptop to an aftermarket EFI, and tune on the fly. Computer control the exact fuel or as close to as exact as the computer can ready from different sensors. You cant control each injector individualy unless you had the computer tapped into the ESC and relay to where it would spray.... Look... its 99% impossible and 100% impracticle ok

Seems like I recall a company that makes a switcher which allows you to have 5 or 6 different chips and switch between them. Maybe something like that?

BTW I'm sure the FI on the old Vettes was mechanical. :cool:

It’s not ever that simple. There are too many variables that you have to take into account so you need a computer. If there was a way to tune a fuel injection car but turning a knob everyone would have it.

You can buy a setup to adjust the pulse width of each injector separately but that alone will not run the car, you have to have the computer.

why would you want to adjust the pulse width of each injector?? Ive seen devices for this but never understood what they are used for.....

Dan

ahh this thread bugs me like a 2 year old with a diaper full of crap...

only way your gunna go FI is the vette way. Either rip off the invaluable intake and other parts, or get crackin on your own set up that mimics what GM did in the 50's.

Pulse width only means how much fuel the injector is spitting out. The computer controls it to get the right air-fuel ratio. That's what the computer does, is tell the injectors when to fire and how much. That's why you'd want to control pulse width - otherwise you'd only get one setting for how much fuel is going into the cylinder.

You just don't fathom how much work the computer really does. There is no way that you would be able to manually control the electrical injectors, and compensate for all the variables and have it run even somewhat decent while trying to pay attention to the road. Since nobody else has the balls to say it, I think your idea is retarded and will never work. Either learn how to program your own chips and stop taking for granted all the work the ECM does "behind the scenes", or get a carb.

And yes, the old 'Vettes had fuel injection, without a computer. It was mechanical fuel injection, a far cry from what TPI is.

Right on!! The computer is seeing many inputs while sending comands out to other things. THe idea of being able to simply control things from the cockpit by turning a knob would be cool, just not probable. The rate at which the computer can do things and how fast things are done, like injector on time, aka pulse width, measured in mS. That's milliseconds. That's really f-ing quick. Most of us, except for me of course:rolleyes: , don't have much ability to do much in a widow a few milliseconds...An aftermarket computer like a FAST or Accel would allow you to tune on the fly. THat is as you drive down the road you can make adjustments with a laptop. The computers are expensive though. Too rich for my blood. I prefer to tune my own EPROMs.

THis post should be done...

yeah, pretty much... but now i know about those computer programs, so its time to start figuring out how those work :)

Go to the DIY PROM board. That is where I learned everything I know about doing my own chips. It has made leaps and bounds with how my "modded" car runs. Go there, read all the "sticky" topics and if you still have Q's, those guys will be glad to answer them.

cap the throttle body holes and bolt a carb to the top of the plenum.....................

And then buy a 6" cowl hood so it will close...:D

better yet install 8 buttons on the back of the steering wheel to manually fire the injectors. 4 on each side, under your finger tips, ala paddle shifter except it'll be "paddle buttons".

you guys are mean....FUNNY but mean.

Dan

This post is completely retarded. The idea of non computer controlled TPI is retarded.

If I'm not mistaken, what you want already exists. Holley Pro-Jection system. There might be a computer inside, but all the tuning is done with knobs on the box. I think Edelbrock makes one also.

Either one will run the engine. But I don't think you will get the results you want.

Because cylinder 7 and 8 get less air then cylinder 1 and 2. So you would have the ability to adjust the fuel for that.

#1. The Bosh CIS-E systems DID use an electronic controller. If you don't want to call it a computer, bo be it. The last one I worked on was in an '88 Scirocco, and it was a poor excuse for an injection system - but appropriate to the POS car it was bolted/wired onto.

#2. Controlling the timing and pulse width of every injector (individually) is called "Sequential Fuel Injection" (SFI), and is controlled by a computer, controller, brain, PCM, or whatever you want to label it. Get a PCM from a '94 or later LT1 or '90 or later blown 231 Bucik and you'll have exactly what you're thinking about.

#3. If you think you have a prayer in Hell of reaching down to the dash, twisting a knob on a potentiometer, and reacting to detonation and mixture changes faster than the ECM/PCM, you need to get back in your car, cut off the seat belts, pick up your cell phone, fiddle with the radio, eat a burrito, and run a canyon course at the same time. We'll wait for the details in the obituary section.

#4. Where the Hell is the moderator? I'll agree with those who point out that this thread has no technical merit, nor value, other than as an example of what should NOT be posted here.

Shew, this post is over.