Not happy.

chomama1 · #1 (**permalink**) 02-23-2013, 06:05 PM

I just got my little 302 Cobra back from the shop, they put a set of Edlebrock Performer aluminum heads on, with some roller rockers. Small valve heads, not the 2.02, the pistons are not notched.

The engine starts great and idles ok, it just doesn't sound of feel good somehow, I cannot even describe how. The shop was not able to access the on-board computer (stock Ford Mustang FI) because, they said, they cannot tell what version (year?) the computer is. I think if we could access the on-board computer, we could tell more about what is going on in there.

I think I'll take it to a more up-scale shop and see if they can access the computer.

Not expecting answers here, I just don't know what to do.

Three Peaks · #2 (**permalink**) 02-23-2013, 06:35 PM

Which cam are you running? Stock cam or......?

Matching up components is the best way to realize the best performance in any engine. A mismatched intake, EFI set up, heads, cam, and program will just about guarantee an unhappy owner.
Find a good shop who understands performance cars/engines and talk to them about what you are trying to accomplish. After a good, frank discussion, you may find a simple solution, a new chip program for your computer, or possibly some additions to your engine in the form of different cam, injectors, mass air sensor, ........

Your budget will probably dictate some of what you agree to do, but this is a first step to being happy with your ride....

bob

DAVID GAGNARD · #3 (**permalink**) 02-24-2013, 09:12 AM

With most any changes like your describing, the computer will have to be re-flashed or have a custom tune put in,otherwise the computer doesn't know what's going on with the new mods and will act accordlingly to not burn up the engine..........they usually run like crap till this is done...........

Find a performance shop with a rear wheel dyno and have them tune it on the dyno and re-flash the computer to your liking.......

Any shop with the proper equipment can have your engine running like a scalded dog in short order and you'll be a happy camper again.........

david

olddog · #4 (**permalink**) 02-24-2013, 10:57 AM

Is it Mass Flow or Speed Density? Mass flow meter or only a MAP sensor?

Just changing the heads should not upset a Mass flow system.

Speed Density would be very unhappy, because it is estimating flow based on MAP and you just changed the relation ship between flow and MAP.

chomama1 · #5 (**permalink**) 02-26-2013, 05:27 PM

Excellent points about going to professional speed shop. The guy that did the work is supposed to know what he is doing, but who knows. I will scout out a real shop with a dyno.
It is stock Ford FI, beyond that I do not know. It is supposed to have mild hydraulic roller cam. Wish I knew!

Dwight · #6 (**permalink**) 02-26-2013, 07:01 PM

If it's a Ford EFI '83 -94 EEC-IV computer it will have a number on it, A9L, A9P. If you have one of those then you will need a custom chip to make all the new parts work correctly.
Is you computer located on the passenger side footbox? Most 5.0 EFI Mustangs had their computer in that location.
I would think any shop that worked on the 89-93 5.0 Mustangs could installed the parts and get the motor to run as it should.
Dwight

chomama1 · #7 (**permalink**) 03-01-2013, 04:34 PM

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This is somewhat blurry photo of the computer connector in my Cobra. At least that is what the mechanic told me. It doesn't look like the standard "D" connector that most Fords have.

The guy that put the heads on for me is lucky to have a concrete floor, much less a rear wheel dyno.