TBI conversion questions and DUI 7 pin conversion

yodabiri

Well-known member
Hello fellow inliners,

During a recent and fairly exhausting search for replacement carburetors for my Mustang with a 250 engine, I came to a realization that there are fairly few options. (I know some may think otherwise, but this is my opinion on the matter)
Before I get flamed for even contemplating this, please stick with me as I am thinking about putting a GM TBI on my Ford 250 inline 6. I know, blasphemy, but there it is.
So why am I even thinking about this? My experience with carburetors has been very lackluster. I know they are "easy" but for me they have been anything but. Another issue with carbs (especially for our 6's) is that availability is shrinking every day. The prices on the autolite 1100s and holley 1940s are definitely not cheap. Going with a TBI system permits the use of widely available parts that can be had from the junkyard for cheap, or even from parts stores if so inclined. But mainly that is not really the reason. I am quite fascinated with fuel injection and TBI seems to be the simplest way to go. I really want to see if I can do this. Some people have done TBI swaps on our 6's already (the tempo tbi comes to mind). I would like to go with a GM 4.3 V6 TBI setup, using the complete setup from an Astro van or S10. I am also looking to keep the cost of this swap down (yes, I know fuel injection and budget should not even appear in the same sentence), so I want to try and stay with a GM (read junkyard) sourced computer and not with MS type system or more expensive alternatives like Howell, AFI, or Holley.
The overall goal for this build is nothing crazy. My main goal is driveability, smooth power delivery and maybe a little bit more performance. I honestly dont even care is the gas mileage improves (as long as it doesnt drop drastically). I mainly want a dependable fuel system that has easily/cheaply replaceable parts.

So far I have been doing research and found a wealth of info for converting carb'd cars to TBI. One of the best overall links I have found is this
http://www.binderplanet.com/forums/show ... hp?t=45292.
I have found a good amount of information for people converting their chevy 250 inline 6s to TBI, and that has been a good point of inspiration so far.
Anyways, the plan is to
- hit the junkyard and source as many of the parts (TBI, harness, most sensors, computer, etc). These parts should be still plentiful and cheap.
- fabricate an adapter for the throttlebody using ~1" Aluminum plate that would allow me to put the TBI unit on my stock big log manifold. (The long term plan is to take a spare head and mill it to install an adapter plate similar to the "modified head" for 2 bbl carb swaps.
- Modify my current DUI distributor to go from the 4 pin module, to the 7 pin (or maybe 8 pin if I go with external module). This is a good link to a similar procedure. If you have any advice on this please let me know. http://www.binderplanet.com/forums/show ... hp?t=46961
- plumb up an electric fuel pump like the airtex E8248 and also the corresponding return line (so the fuel sending unit needs to be modified a little bit to have a return line barb).
- Also include a inertia shutoff switch for safety.

I am just starting out on all of this, so any constructive input would be greatly appreciated. Please let me know if I am forgetting something, anything to stay away from, anything else I should consider. I am currently wading through tons of threads on TBI conversions in various settings from old v8s, to more recent jeeps, etc. As I progress with this build, I will update this post and let you know how everything is going.
 
This shouldn't be too hard to do. The hardest part will the the throttle body adapter.

If you start with a 1227747 ECM and pull the system from a 4.3 liter V6 it will probably run as-is on a stock 250 with little additional tuning needed.

A Duraspark and a DUI will provide the same signal to the 7-pin module. You need to lock the advance mechanism.
 
I put a GM TBI on a ford 250 inline six. I have the engine my 66 Mustang. I used a 250 2v head and intake and Mega Squirt 2.0 ECM to control everything. I used Mega Squirt so I could control everything with my laptop and not have to get some one to burn a chip for me. The sensors were cheap and I did the wiring harness myself. Car cranks and runs well. Get much better fuel mileage than the two barrel Holley I was using. Good luck with your project!
 
Thanks for the responses. I am curious about the hood clearance. And also dayman, do you have any pictures of the setup that you used? I am trying to figure out hood clearance and if it will be an issue. If I have hood clearance issues, I have an old and already cut spare hood that I will put some sort of cowl scoop onto.
 
I will get pictures posted this weekend.

I used Maverick motor mounts and drilled new mounting holes on the frame to lower the mounts to get more hood clearance.

I am using the Aussie 250 2V head and intake on my 250 engine. The intake has the same bottle pattern as the carb on a Jeep six cylinder. I bought an adapter to mount a GM TBI to a Jeep intake manifold. See link.

http://www.affordable-fuel-injection.co ... 49-23.html

If your head was modified to mount a two barrel carb, it would be much easier to convert to fuel injection. You can buy a kit from Affordable Fuel Injection which will save time and money and it works. There are several vendors who provide kits. I am not trying to sell the Affordable Fuel Injection kit. They are just one of many out there.

Checkout this link it may help you.

http://classicbroncos.com/forums/showth ... p?t=190200

I did only a fuel conversion. I did not integrate the ignition. I will do it later or not.

You will like the EFI. Car starts better than it ever has and has more power and better gas mileage.

Here is another link of interest. This is a V8 with TBI, but it is the same for the six cylinder if you use the GM TBI. http://www.diyautotune.com/tech_article ... 1-nova.htm
 
I have some photos for you. New at posting images. Hope this works.







The fuel pump I used was a Carter 5000. TBI has internal regulator. My fuel tank has a drain and I used it for the pressure line and I used the regular fuel line for a return. Tank really needs a baffle to keep fuel at the pickup when taking hard corners, but I wanted to go the simplest route first to see if I could make it work.

If you decide to use the 1227747 ECM, I have an ECM and I have a new wiring harness I don't need. I will make you a good price for both. ECM has been modified for a removable chip to make programming easier.

I decided to use MegaSquirt so I would not have to get someone else to do the programming. I wanted to learn how to do it myself.
 
Wow, true to your word!

Here they are in fullsize without having to download from your website...we''ve lost a lot of great 200/250 induction system photos over the last11 years, like a Ken "tri-power 250"'s (250 triple Carter Weber equiped I6), and don't want it to happen again.

viewtopic.php?t=63791#p487947



http://www.fordsix.com/forum/viewtopic. ... 27#p496827
dayman":3scwfkt9 said:
Thanks rbohm, kevinl1058, and Econoline64 for the feedback and comments. Really helpful. I decided to go with the

CSC-264-HDP-10
264/274-110* Hydraulic Cam - Dual.
I think it will be a better all around choice.

kevinl1058 - That is one cool looking Falcon. Really sounds great. Very impressive. Wheels really awesome!!!

I will post up some photos as soon as I get something worth seeing.

I've found the 250 to be very responsive to much bigger cam profiles, and able to cope with standard Jeep 4.0/4.2 or 258, or GM 4.3 or 262 TBI. Or the standard EECIV CFI used in 3.2 and 3.9 TBI 120 to 170 hp engines used down here from 1988 to 1991.


Its an easy nut to crack with Classic Inlines cam, carb bonnet and the expert US and Aussie advice that make the 250 such a satifying performance mod. dayman, props to you, you have done very well.

I guess it idles even smoother than MPG Mustangs old 200 cube TBi Mustang video evidence, as its the same cam and TBI, you just have another 50 cubes to soften the idle? It must be super economical with the T5 and those axle gears.

My personal experience with all the biggger longer stroke Ford engines based on the smaller garden variety engines, is that as soon as you add a 16 to 25% capacity increase by stroking, you can use both higher flowing heads and wild cams without any issues.


Any of the log, 250 2v head, Classic Inlines or alloy cross flow heads just love the widler cam profiles with the 250, you can't really go wrong, aut or manual, throttle body, port induction, single or triple carb.
 
Back
Top