347 EFI with AFR 185 Heads

[Lunchbox]

Today a saw someone asking about parts for the converting over to a 1990 Mustang EFI system. This is what I did thinking that its easy, people have done it and it’s cheap but in the long run it just didn’t pay. If you are looking at doing this think about it and look long and hard at some of the standalone options.

Problems I had. Starting with a pro built engine with all new parts and block.
Burnt out circuit in the first computer, took a month to track down.
Bad compression in one cylinder cracked a prison. Fixed that one in place.
Restarted, bad compression in a other cylinder. Pulled engine full rebuild.
Waited 3 months to get it into the best tuning shop in Seattle.
Turns out the computer not programed right. Re-chipped and tuned.
Now the stock Mustang intake starving for air limiting HP.
I will replace the intake this winter after I finish paying off the $$$$ in fixing the engine.

thanks for letting me rant

 

[WheelHorse]

Man, talked about a load of headaches. Did you crack a piston from detonation?

 

[Lunchbox]

Yes, the cracked pistons was from detonation. i was a bit mad about it as i had a custum engine shop look at it before and durning the problem

 

[Mountain Ram]

Wow... Was there a problem with the pro-built engine or detonation like wheel horse asked? Seems like it should take more than a month of detonation to crack a piston... And with a burnt circuit- would it even run?

I had a few small issues- mostly created by me- at the end of my 347 EFI build. I haven't noticed any detonation... Or any issues other than a slightly rich fuel condition (caused by the 30lb injectors and no tune yet).

Sorry to hear about your issues and I hope you get it all worked out, but I would have to say there are probably more EFI successes on here than failures.

 

[Ethansdad73]

We all have bad experiances from parts to vendors. But we are all here to learn.

I eventually will go with the EFI but will be doing it on a stock 302 to start then once all is good install it on a 351/5.8. There is always something some more than others but with help with people here and local bronco brothers its geting done.

Sorry that you had bad luck with your build.... been there ( rolled 3x at 55mph ) but "when in hell, keep on trucking thru it" or something like that anyway.

 

[AZ73]

One reason I'm starting with a carb on my fresh 347 first. Doing the ground up I just don't want to deal with more issues than I have to. I subscribed to Mountain Rams build and will be referencing if/when I switch over.

 

[Mountain Ram]

One reason I'm starting with a carb on my fresh 347 first. Doing the ground up I just don't want to deal with more issues than I have to. I subscribed to Mountain Rams build and will be referencing if/when I switch over.

I really need to get back to that thread with more pics, notes and a cost total...

 

[airbur]

Thats depressing.

The Mustang EFI setup is one of the most solid available.....one of the reasons I chose it. Anyone considering EFI should definitely consider it.

It sounds more like you had a sub par builder and an inexperienced tuner. Also, a few mistakes made in choosing parts...intakes etc.

Hope it's running good for you now.

 

[ilovemaui]

That is a bummer. The ecu would have had to have a visible add on. You can't just hook it up and modify the settings without an aftermarket add on. If someone got into the tuning they could very easily set the advance to high. What octane are you running and what is the compression ratio? The higher the compression the more you can advance it but you need to run higher octane fuel.

 

[englewoodcowboy]

Its these problems that you will inadvertantly run into with re-purposing an older system. I think the new TBI systems out there are going to be a much better alternative when it is all said and done.

 

[KyleQ]

Today a saw someone asking about parts for the converting over to a 1990 Mustang EFI system. This is what I did thinking that its easy, people have done it and it’s cheap but in the long run it just didn’t pay. If you are looking at doing this think about it and look long and hard at some of the standalone options.

Problems I had. Starting with a pro built engine with all new parts and block.
Burnt out circuit in the first computer, took a month to track down.
Bad compression in one cylinder cracked a prison. Fixed that one in place.
Restarted, bad compression in a other cylinder. Pulled engine full rebuild.
Waited 3 months to get it into the best tuning shop in Seattle.
Turns out the computer not programed right. Re-chipped and tuned.
Now the stock Mustang intake starving for air limiting HP.
I will replace the intake this winter after I finish paying off the $$$$ in fixing the engine.

thanks for letting me rant

Burnt out circuit in the first computer, took a month to track down. - Someone used the wrong EGR harness with the wrong computer, someone's ignorance killed that.

Bad compression in one cylinder cracked a prison. Fixed that one in place. - Junk motor or rebuild
Restarted, bad compression in a other cylinder. Pulled engine full rebuild. - Again, junk motor - not EFI problem

Waited 3 months to get it into the best tuning shop in Seattle. - Didn't need to do this, but that is up to you

Turns out the computer not programed right. Re-chipped and tuned. - The computer you got was pre-tuned, a factory untouched computer would run a 302, 351, or even a 408 - it all depends on what cam is installed.

Now the stock Mustang intake starving for air limiting HP. - Well yeah - its a choke point on a bone stock 302, what did you expect with high CFM cylinder heads?

The problems you ran into were a junk computer and getting another non-virgin computer. The bunk motor sucks, can happen to anyone.

Sorry to hear you had to throw money at it to get it to work - but for anyone putting together this setup, be known that the Mustang EFI setup is very versatile and will correct run damn near any Ford Windsor motor depending on the cam. If you get away from the 112LSA profile you get a lopy idle, which pulses the air through the MAF and confuses the hell out of it.


Mustang EFI ran my 302 perfectly and is running my 351W perfectly as well - no tuning required. You could tune it to get ever single HP/TQ out of it, but we are not chasing 1/4 times or E/T's - we just want torque that starts in any temp, any elevation and will keep running at any angle.

 

[NYLES]

Kyle you tired?

Mine runs great with a loppy ass backwards timed cam, what you talking bout willis?

All thats just pushin ya buttons, however you are very correct the mustang efi set up will run damn near anything....and it can out tune any man alive!

 

[KyleQ]

Mine runs great with a loppy ass backwards timed cam, what you talking bout willis?

What is the LSA of that cam? From what I've been told they really like to be close to the 110LSA range..

What do you mean backwards timed, like retarted timing or just timing without a pointer or light?

 

[NYLES]

backwards as in old firin order.....ill have to look up lsa...it is 110

 

[av bronco]

By any chance did the the pro built motor have kb pistons in it?

 

[HoosierDaddy]

I usually suggest that one should install the EFI on a known good motor first , then do the engine swap. The orig. post just proves out why that should be done.
In effect , the efi swap as far as the rest of the motor is concerned , is just an intake manifold swap. So if problems are encountered , you know where to start looking ... the new or modified systems.
I can't imagine trying to install an unknown efi system , ANY system , on a new performance motor that is far from stock (and improperly designed to boot) , a nightmare waiting to happen.