I have a fleet side 57 f100 with original 272 and 3 speed tranny. I recently converted it to 4bbl and threw on an efi kit from fitech. Everything went perfect until I tested it on some large hills in my neighborhood. The truck just sputtered and died. The efi tried to keep it alive but couldn't. I thought at first it was timing but I confirmed the timing was good.

Do I need to do something to the transmission? It is all original so almost 60 years old. I don't know enough about transmissions to say for sure. Is my tranny not able to support the new horsepower?

It does not have the auto option on the tranny either.

Thank you all in advance for any help you can provide.

Assuming that the carburetor was properly tuned, the difference in horsepower would be minimal, if there is any difference at all so that is probably not your problem.

If it was fine with the carburetor, then it is some issue with the fuel injection system.  Go back and double check the entire install, then look for FAQ's and maybe contact FITech if it seems that everything is done correctly.


Lawrenceville, GA

Thanks. That is exactly what I was thinking too. I think maybe the afr targets are off. I love the fitech product but I haven't had the best experience with their customer support.

I will wipe everything and start from scratch on the efi.

If you can, leave the hand held control unit attached, it may give you real time readings

I don't know if this applies to your situation but I'll throw it out anyway. The Boss EFI throttle body I have used offshore GM components for the TPS, Map, etc. They were prone to failure, and the unit would go into "come home" mode, high idle, down on power, but would get you off the freeway. My dyno guy who did the install pulled all of them out and replaced them with Delco parts. That's actually his first tuning step with most aftermarket units. So you might want to run the diagnostics on those components first if the hand held unit allows it. My computer is an Accel Gen 7 and it's laptop programmable but lets you check almost everything for full signal range.


miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Grea info. Thanks. I'm going to get into it today/tonight. Will update as I get improvements.

My understanding is that EFI requires much higher Fuel Pump pressure to work properly. What are You using for a Fuel Pump and are You still using the original size Fuel Line from Tank?

  

The kit I bought has everything. The throttle body pre and mid and post filters as well. It has an auto learn fx for the unit as well. It came with all new hoses 8n and 6n respectively.

After re re rereading everything the one part of the instructions for installation states that the fuel hose from the tank to the pre filter cannot be longer than 3 ft. It is currently 4ft bc the bottom feed drain plug on the tank is on the passenger side.

The fuel filters and pump are gravity fed. According to the readouts on the handheld display the pressure is on target even at 3500rpm.

You might check the tank for crud, watch you fuel pressure gage if you have one. Check te fuel filter to make sure it isn't clogged up with something from the bottom of the tank.


Frank/Rebop

Bristol, In ( by Elkhart)