I need some help being sneaky (EFI swap)

So I really want to do the Tempo EFI conversion. My problem is my mom heard the cost and she wants me to work on paying her and my dad back first. I can buy anything I want for the car provided it's not over $200.

So my plan is to prep the rest of the car for the EFI first in the hopes of a lot of smaller costs are taken care of and I could at least try to use the line "but everything else is already there"

Somethings I need to know however are:

1) Can I get an electric fuel pump that will be able to handle the EFI when I finally switch over BUT at the same time be able to regulate the flow down enough so I can use it with the stock carb?

2) I've been told to replace the linkage system with a cable type setup. Again, would it be possible to buy a throttle cable to work with the carb then later be modified for the TB.

3) Can I install a bung in the exhaust system for the o2 sensor and put a plug in until I'm ready for the rest of the swap? Also, should the bung be in the manifold or in the pipe directly after the manifold?

4) Same goes for the return line. Can I simply install a bung on the tank for the return line but block it off until I'm ready?

Anything I'm missing? Thanks.

1) Im not %100 sure, but i dont think there is a pump that will do what you want.

EDIT : I beat you to it wallaka! But about the pump, any fuel pump made for 12+ psi will have a high flow rate. To get it down to 4-5psi, you would need to make sure there is VERY LITTLE restriction in the fuel system. You would also need a regulator, which you dont need if you are getting a tempo throttle body.

3) The o2 sensor should be in the pipe, not the manifold. When you buy the bung you most often get a plug with it, so thats fine to do.

4) Yes you can run a return line without hooking it up. Run it all the way to the engine bay and tape the end of it up. Also run it to the rear of the car and tape that side up as well. I did not modify my gas tank for the return line, i just used the drain plug for the return hole. Remember you should aim for minimum rubber line, but you need a little of it at both ends of the steel line.

The megasquirt is about a $200 investment... but that might be pushing what you could get by with.

How about the throttle body, that does not cost much if you look around. What i did not do on my project, because i was in a hurry to get it running, was polish the throttle body. If you have time, maybe its something to look into?

1) Can I get an electric fuel pump that will be able to handle the EFI when I finally switch over BUT at the same time be able to regulate the flow down enough so I can use it with the stock carb?

You'll need a regulator that goes down to 3-5 psi. Not a problem. You'll need a return-type, though. The dead-head type don't work as well.

2) I've been told to replace the linkage system with a cable type setup. Again, would it be possible to buy a throttle cable to work with the carb then later be modified for the TB.

Yes. You might have to modify the bracket, but it is a minor thing.

3) Can I install a bung in the exhaust system for the o2 sensor and put a plug in until I'm ready for the rest of the swap? Also, should the bung be in the manifold or in the pipe directly after the manifold?

Put it in the pipe. A plug will work fine.

4) Same goes for the return line. Can I simply install a bung on the tank for the return line but block it off until I'm ready?

Yes.

Anything I'm missing? Thanks.

It sounds like you have it covered pretty well.

Absolute first thing I would fit, is an adjustable return-style regulator and gauge.

There is one with an interchangeable spring, so you can run it below about 15 PSI, or up to about 60. Can't remember what brand, but Summit sell it. Hook up your current fuel pump to it, with some hose barbs and rubber line. Now you always know (and may control) your delivery pressure.

Next step, would be working towards EDIS, driven by the Megasquirt computer. For this you will need to spend some extra money. I'd get it going so the ignition curve was fully computer driven and you were running coil-on-plug or waste spark (with three coil packs) ignition.

If the engine is healthy enough, welding in an oxygen sensor is next step; you can log the results through MS, for benchmarking purposes.

Final stage would be the TBI or similar fitment, but without the other bits working first, system diagnosis and flexibility are always going to be challenged.

why go EDIS if doing it on the cheap? Build a EEC4 dizzy and be done with it. just get one from a 2.3L OHC motor, swap the reluctor wheel with one from a 6cyl car (2.9, 3.0, 3.8 etc.) and pop the 6cyl cap on it and the 200 drive gear and you are done. then you have a plug in timing setup for megasquirt using the basic EEC4 wiring.

BTW why not look into a CFI setup off a 3.8 or 5.0L car? easier to bolt on to the 200 (use an adaptor from mike) and hook up the cable throttle to. Supports more power and has a built in regulator (could mount a 5.0 adjustable one on it even)

turbo - the tempo is a bolt on for the 200 head, i would say that is easier. The tempo also comes with an adjustable regulator built in. But your right about those cfi setups supporting more power.

Ok, I need to clarify one thing. The Crap-O-Matic dizzy I have now won't work with efi?

Also, how does the CFI from the 3.8/5.0 cars differ from the Tempo unit?

With something like a megasquirt (and I assume others) you would not have to do spark control so you could leave a stand alone dizzy. Problem with the load o is the throttle bodies dont have the scv port so you would never get it to respond right. MS could trigger for fuel only off any dizzy. For spark control you need something with a pickup coil (like duraspark) or have to adapt some sort of crank trigger. If you have a load o and want to work in stages I would do a DS2 or DUI first and get it working before starting the efi fuel only swap. Once you get the fuel only working you can easily move on to spark control. Fuel and spark at the same time can be a lot to get working for your first project.

The tempo is a 1bbl that is almost a direct fit and has that handy 90* plenum built on which gets you around the usual air cleaner issues. The 3.8 & 5.0 are 2bbl so you are back to all of the same issues you have with a 2bbl carb, either modify the log for direct mount (but if you can do that why not just go multiport) or use the flat adapter where you can debate all day long if it is worth it because of the sharp bends or use the tall adapter and have hood/air cleaner issues. If you want to do a 2bbl TBI I would use the GM ones. They are by far the most common because they were used on most GM cars from 80-90 and all the trucks/suv 87-95. That means they should be cheap and easy to find and support also several injector choices. Holley also made direct replacements for them as well as their own Pro-Jection line. The fords were only used for a couple of years on a few models. My favorite yard had 2 CFI's out of 500 cars last time I was there. Lots of 5.0's and GM TBI's along with a good selection of carbs.

So most likely I'll be using the Tempo unit then.

My LOM dizzy has an Ignitor kit in it, would that alleviate the changeover or not?

blueroo":2i9rgek8 said:

So most likely I'll be using the Tempo unit then.

My LOM dizzy has an Ignitor kit in it, would that alleviate the changeover or not?

Click to expand...

No.

With a computer controlled ignition, You want the distributor to provide static advance and that is it. Other than that, it acts as a trigger only.

The computer delgates dynamic advance, and it does so by deciding when to fire the module.

You can accomplish this several ways, probably the easiest is to weld the mech advance plate static on a DSII and use the MS to fire it directly.

Bort62":1u1lmcv4 said:

blueroo":1u1lmcv4 said:

So most likely I'll be using the Tempo unit then.

My LOM dizzy has an Ignitor kit in it, would that alleviate the changeover or not?

Click to expand...

No.

With a computer controlled ignition, You want the distributor to provide static advance and that is it. Other than that, it acts as a trigger only.

The computer delgates dynamic advance, and it does so by deciding when to fire the module.

You can accomplish this several ways, probably the easiest is to weld the mech advance plate static on a DSII and use the MS to fire it directly.

Click to expand...

Since the LOM doesn't have a mech advance, couldn't he just disconnect the vacuum line? Seems like that would lock it out.

To do fuel only with MS all you need is a basic tach signal that can come from anything, points, igniter, electronic module, whatever since its the same signal you are sending to the coil. For fuel only the Load O wont work because you loose the SCV port with the carb. A regular points (or converted ) dizzy would work but not the load o.

I believe to do spark control with MS you need a better signal like from the pickup coil of a DS2 or DUI or even better something like a crank position sensor. MS2 3.xx can then direct control a coil if you want to or drive a module that was used for controlled timing like a TFI or the 7 pin GM or even some of the more advanced MSD type boxes. With the DS2 or Dui you need to lock down the mechanical and vacuum advance mechanisms. When doing this you also need to 'index' them so that you are fairly centered on the terminals when the system is firing. Its fairly easy to do all you need is to hack up an old cap and look with a timing light to see where the rotor is in relation to the terminal when it fires if its off you rotate the dizzy to get it closer. WHen you move the dizzy it will change the timing so you go into the MS and change the trigger offset to get the timing back where you wanted it. WHen you do this you have to think about the range of your timing and do the adjustment with it in the middle. At least with the 6's there is a lot of room between terminals so cross fires are not as likely like on some of the small cap v8's.

wallaka":3vos3zz9 said:

Since the LOM doesn't have a mech advance, couldn't he just disconnect the vacuum line? Seems like that would lock it out.

Click to expand...

I had thought about this, but I would probably want it physically locked out, not just flopping around in there.

Also, you need a magnetic trigger for the MS and the LOM doesn't have that. Using the points won't work.

At least, It shouldnt...

Bort62":c5opwu8p said:

wallaka":c5opwu8p said:

Since the LOM doesn't have a mech advance, couldn't he just disconnect the vacuum line? Seems like that would lock it out.

Click to expand...

I had thought about this, but I would probably want it physically locked out, not just flopping around in there.

Also, you need a magnetic trigger for the MS and the LOM doesn't have that. Using the points won't work.

At least, It shouldnt...

Click to expand...

Yeah, I wouldn't want to blow one up trying it out.

Well, thing is the MS is going to measure the oscillating pulse output by a magnet spinning past a hall effect sensor.

The points closing and opening by themselves generate no such pulse. The points mechanically short the coil terminal, causing it to spark. I would imagine one could make the points work if need be, but why when there are much better alternatives out there?

I dunno

locked out dissy is EASY...


get a 2.3L OHC EEC4 unit
get a cap and reluctor off a 6cyl eec4 car (they are all the same and the reluctor just has two screws holding it on)
put these two on the 4cyl dissy.

press off the 2.3L drive gear, press on the 200 drive gear. drill hole and install pin......DONE!!!

now you have a locked dissy with electronic ignition that will work nicely with a megasquirt. OR if you use a 3.8L ECU and CFI you can prob just go that route.

no need for a direct mount on the CFI. just get an adaptor and be done with it. some simple wiring and you shoul dbe able to get it up and running.

you end up with this....