I'm looking for suggestions for parts to convert by carburated 390 to throttle body fuel injection. There's affordable fuel injection online - are there other good options to consider?

Peter

 

What do you consider affordable? I've got the Holley Commander 950 TBI setup on my 390.

If you think that's too much, you might look for something that had TBI originally, probably a chebby , and run a Megasquirt ECU. That will be more work than the Holley setup though.

 

I recently ran across this site www.affordable-fuel-injection.com. I also found a site awhile back about a do it yourself fuel injection system that was very inexpensive but I can't remember at the moment the site name. I'd like to try fuel injection on mine basically because I'm a bit of a computer nerd and I like the idea of hooking the laptop up and playing around with things.

Tracy

 

I like the affordable-fuel-injection site and their kits interestings. I'm hoping someone on this board has more information about it.

If anyone out there is running MegaSquirt on an FE I'd love to hear about it - I'm just not too interested in pioneering on a do it yourself kind of kit. If there's a kit that contained all the elements including the megasquirt with appropriate tables, I'd probably buy that - I like the MegaSquirt concept.

I may end up with the Holley, the package is a lot like the Affordable system. The affordable system is cheaper, but I'll have to compare the components in each side by side to see if they offer the same things.

I was hoping someone would say something like - You can get a throttle body of a '88 Pinto and then an ECU of a 93 Pacer and it all costs $600.



Peter

 

Rusty,


Where do you mount the O2 sensor with headers, at the collector on either side? Are there other installation issues with the Commander and FE motors to be aware of?

 

The O2 sensor is mounted in the collector on one side.

The Commander has no special issues with the FE motors. They do not include any base maps (computer configurations) for FE series engines, but I'm willing to send anyone the map I'm using as a starting point.

If it has a 4 barrel manifold, you can run the Commander 950 TBI fuel injection on it.

 

The Holley site says you need to make some adjustments if you put the 02 sensor at the collector because of the drop in temperature from the head - have you done that? There's a 950 on EPay right now supposedly taken off a motor home after 100 miles. Think it's worth buying?

 

If they're selling it, there's probably a reason. I'd pass.

They send you a heated O2 sensor. You dont have to worry about it. The software even tells you when the O2 sensor is up to operating temperature. It might take a few seconds with a cold engine. I think the warning is more for people using non-heated O2 sensors.

 

The megasquirt is very easy to use. My advice is to buy a pre-assembled kit and start there. The little *******s really do take 4-5 hours of soldering tiny leads together and then there's the chance it won't work. The first one I built didn't work right so I rewired it to run my fuel injector flow bench (I'm in the fuel injection business) and built another one. They only have 2 or 3 wires for the fuel injectors depending on how you run it. The sensors and wiring is very simple even for an electronics idiot like myself. It's all pretty simple if you have patients. Converting an old truck to run an EFI 5.0 engine with a stock harness was way more work than installing the megasquirt on a 390 with port injection. No matter how you do it, you will likely have atleast a grand tied up in injecting a 390, megasquirt or not port or throttle body. Fuel injection hose is $10 a foot, sensors are $20+ each, EFI fuel pumps aren't cheap and stockers won't suck from your cab tank without a regular pump to prime it. It is nice to turn the key when it's 17 degrees out and it fires right up and idles perfect though.

If you really want cheap go with the GM throttle body and buy the ebay adapter or make your own real easily, buy the cheapest megasquirt, buy the frame mounted fuel pump off an 87 to 95 ford truck or van in U-pullit and one of those cheapo Napa electric pumps to feed it from the tank. Rip all the wiring out of your buddy's 5.0 mustang drag car project he'll never finish and use all the relays and sensors for your truck. You can probably get 250 or more horsepower from these parts until you'll need to shell out money for aftermarket fuel system parts.

Once you get to playing around with it, the only thing simpler than EFI is a motorcraft 2 barrel.

Dustin

 

Thanks Rusy and Dustin for the great information.

Dustin:
If I went MegaSquirt (and the cost wasn't bothering me) what throttle body should I get for my 390? And, do you have the tables for a 390?

 

Since I can't figure out how to edit my previous post, I'll just have to add to it here.

I've seen throttle bodies by Holley, Edelbrock, MSD, Accel, etc. Are they different. Some have 4 injectors with fuel rails and some it's hard to tell if they come with any injectors at all.

Rusty: Is the Holley system speed density or mass air?

 

It is speed density. But since it is fully programmable, it can be programmed to run on any engine, with any parts (cams etc.) where a non-programmable speed density system would not.

 

Rusty:
Is this the truck with the blower? How much work is it to adjust the speed density systems when you make major changes in your set up like a blower or a different cam?

 

I only wish I had a blower!

Nope, no blower here. All N/A.

When you make major changes, you'll have to reprogram the fuel table. It takes some time and is probably best done on a dyno or back country road where traffic conditions wont interfere. Basically, all you're doing is tuning it off the O2 sensor. Real simple, just time consuming.

Here's the instructions from Holley as they come with the unit. Be warned, it's a 5.9MB download, and it will take you some time to read. But it should tell you everything you need to know about the system.

 

Didnt the late 70's or early 80's thunderbird have a throttle body EFI etup on it. I vagly remember my dad's thunderbird haveing TBI on a 302 or 351W . couldnt that system be converted for Fe ?

Is their really a driveability and MPG's to gained with a TBI over a well tuned carb, enough to justifi the change over ?