EFI conversion help!!!

Efi

You might want to do some homework on EFI systems before you tackle this swap. This will save you lot of $$ in the long run.
Return EFI uses a fuel rail mounted regulator the returned unused fuel to the tank.Your stock line would be a good line to use as a return then just add a new line for the feed. Theres alot more to this system than just fuel supply.

$200 is good if thats complete with PCM. Look for signs of corrosion or burn marks. Also check all the connectors on the harness for cracking. Vince

Flowtech offers a weld in able Bung for O2 sensors, the idea is to get them as close to the main collector as possible, you want the best signal from all cylinders.
good luck with the swap

I have detailed my swap on my home page under tech articles. Another good source for EFI info is www.fordfuelinjection.com

u can run a return line into a special metal splice that splices into your filler neck. this is much easier than brazing a new metal outlet to the tank, and is much easier. jegs and summit both sell them. just .02 to help u out. ive always wanted to go efi, but gotta love the carbed thing sometimes too, especially on a weekend cruiser.

what kind of mpg gains does this conversion make in a classic stang?
i get about 14-16mpg cabed in my 69 302, and my 5.0L Monster Miata (2350lbs) only gets about 20-22mpg.

or is this more a conversion for better throttle response.

84convertablegt said:

u can run a return line into a special metal splice that splices into your filler neck. this is much easier than brazing a new metal outlet to the tank, and is much easier. jegs and summit both sell them. just .02 to help u out. ive always wanted to go efi, but gotta love the carbed thing sometimes too, especially on a weekend cruiser.

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Part number or link please?

The return line into the filler neck is a hokey setup IMO. Anyone can solder a piece of 3/8 steel line into a sending unit in 10 minutes, I dont know why people are so afraid of it. I suggest you check out www.fordfuelinjection.com. Not trying to discourage you ,but if youve got a factory harness that hasnt been modified for your car and youre lost on the fuel supply and return then this may be a project thats a bit over your head. You'll get alot of help here but this can get frustrating.. With that said, if you understand what an engines basic needs are, can read one line scematics,can solder proficiently and have a bunch of patience you can do this, its not hard just requires some perserverence and a place where you can be left to think without being bothered. If you cant do any of that then I suggest you buy a pre made harness. Before my harness was complete I had about 5 miles of wires strewn across my shop.

You can modify or have the stock wiring harness modified by such places as Windsor Fox. I do not recommend them (run screaming away). Your best bet is to get an aftermarket harness from Ron Morris Performance. I think Painless may now offer one.

The fuel return is not a big deal, but the unbaffled stock tank can allow fuel starvation when the tank gets about a 1/4 full. You can live with it, install an external accumulator (surge) tank, or modify your stock tank. One downside of an external accumulator tank, is you'll need to wire in a second low pressure fuel pump. Someone on here posted pictures on a website of his tank modifications.

70XR7ConvertCat said:

You can modify or have the stock wiring harness modified by such places as Windsor Fox. I do not recommend them (run screaming away). Your best bet is to get an aftermarket harness from Ron Morris Performance. I think Painless may now offer one.

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I have heard BAAAAAAAAAAAD things about Windsor-Fox. I know it was rumored that they were going out of business. Another source I have heard very good things about is www.fordfuelinjection.com that was mentioned above. I have heard they can be a little slow on delivery but the product is top notch.

67staaang said:

thanks. guys im planning to start on this project soon. do you guys know if the gen 7 computer is out for sale? i heard that is the top notch cpu out there for EFI systems

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Unless youre running an all out race car the Ford EEC IV is more than adequate,anything else would be a huge waste of money. Im running a 425HP 331 using a standard A9p processor,90mm Mass air meter from a lightning and a 4 program chip.. Theres ALOT of tuning capablity with the EEC using products like the Tweecer or PMS. In addition to that the wonders of the EECs built in adaptive strategy are amazing.

Youre going to need a TFI distributor, The MSD isnt going to swap. The stock ford TFI(thick film ignition) EFI distributor is very good. Doing an EFI conversion can be alot of screwing around but its VERY rewarding, and If you take your time and build your own harness(everything you need to know is right on www.fordfuelinjection.com) you'll have a good handle on EFI when youre done and you'll be in love. I'll never own a carbureted car again.

I got my harness from a 93 GT for 100$, 200$ I've seen go for really good stuff, so if any of it looks rather worn try to talk him down.
Ford Fuel Injection is great... I got through most of the re-wiring of my harness in about 3 weeks with going to school and working. Shipping from them wasn't slow, at least for me.

Take your time with the harness and read up on everything on fordfuelinjection.com's site.

Fuel wise is a big debatable topic. Most people I've seen run a new line for the feed and the old line for the return. You can do this, or you can run whole new line (like what I'm doing, 3/8" alluminum tubing from summit), or just run lots of soft line, but that gets expensive.

You also have to choose what fuel pump style you will use. A lot of folks choose a frame rail mounted one out of a 80s model ford truck. This is easy and only requires the soldering of a return line to the pickup. The problem with this set up though is that is sometimes will uncover the pick up during cornering at low gas levels leaving your pump sucking air. Not good.

Another way is the constuction of a 'header tank' whereas a small sheetmetal or alluminum enclosure is built to house a standard 5.0 pump. This uses a second, low pressure pump, to feed gas into the housing so that the high pressure pump is always kept fed. Any sloshing will be so minimal in the header tank as to not uncover the strainer on the end of the 5.0 pump. The enclosure uses a feed line from the low pressure pump, then a feed line out to the engine. The return line also goes into the header tank to continue to replace fuel that is pumped out, lastly a return line to the fuel tank is used to alleviate any excess fuel that the header tank cannot hold. Problems with this set up are that the tank can be difficult to come buy for a novice, let alone construct, and it is complicated. (On this note, for followers of this method, how are the electrical connections passed through the wall of the tank? I mean, what do you use to keep pressure and gas from escaping and not grounding on the body of the tank?)

Third method can be considered the most drastic. This involves the placing of a fuel pump (5.0 type) into the stock gas tank. This requires a fair amount of modifying of the tank for how you do this. One member on here elected to build a baffled enclosure to drop into his tank. I personally am going to attempt to braze baffles into the tank in an attempt to utilize a modern drop in style arrangment.

Yes, unfortunately as tt670 said you will need a new distributer. Sell that one to someone locally and either get a new MSD or for more of a daily driver a junkyard or auto parts house one will work fine. Just be wary of the gear material selection, iron or steel. It has to mate right with your cam gear or you'll be doing alot more work than planned.

That's all I can think of for now.
The Swede

67staaang said:

hey guys i jus purchased this for 195. you think it was worth it?
now i have like uhhh 40% of my EFI project complete. err..

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Thats an OK deal if its all in good shape.. I cant see real clear but It looks to me like the hoses are clamped to the fuel rail... Thats a No-No!

sorry to upset u but ive bout that basically same setup for around 75 at the races and 75-100 seems to be the going rate but u got it now so continue on with the work

From an EFI conv on a 68 Coupe...
We ran new lines. Mounted the pump on a plate. Tank was baffeled. Works great!

Thought I had a picture of the bottom of the tank. This one shows the fuel filter and the two lines running forward on the right. THe wiring was quite the project. I think the harness was Windsor-Fox. I modified nearly all of it...one wire at a time. We spent two summers just getting to the point where we could start the car up. The O2 sensors gave us a lot of trouble. If you can use shorty headers then try to go that route. The long tubes we installed I understand are now coming back out.