94 Cobra Moral Dilemma

Dscraggle said:

I have a very clean and straight 1994 Mustang Cobra with the right documentation and all of the correct parts on it like the correct hood and bumpers etc. I bought the car for a really good price as it needs engine work. The motor doesnt run right and has to come out of the car, it has a dead, flat miss in it from 2500-3800RPM. When i say flat spot I mean FLAT.. It just boggs and sputters no matter what I do to fix it. Ive checked everything from the rocker arms, to pluge, different carbs, etc. EVERYTHING I can change or replace with new I have done. Now this post isnt about how to repair the car or looking for technical advise. The motor in it now is supposed to be a 331 and has aluminum heads, roller rockers, a edelbrock intake and a new Quick Fuel Brawler carb. MSD ^AL and distributor, etc. It sounds rowdy and the camshaft is at least .550 lift by the way it sounds. The motor has to come out for 2 reasons.
#1- I have to know what it really is, all stock with a cam and generic heads or is it a stroker crank, rods, and pistons. If its a stroker then hyper, cast or forged pistons? Cast crank or steel? etc etc
#2- For Repairs. Whats wrong with it? Broken rings or lobes wiped off the camshaft?? etc
I bought the car to fix up and probably sell for a profit so I can buy another Mustang. Hopefuly nicer than this one.
My dilemma is whats the best way to go back together with the motor? I found a complete 1994 Cobra engine complete from intake to pan for sale local to me for 1000$
It comes with the right ECU and wiring harness, everything needed to go back efi and mostly stock. It still has the factory AC and all that, I bought a nice set of ceramic coated long tube headers and matching X-pipe, and i bought 3" Stainless tail pipes, stainless Magnaflow mufflers, Cobaly gauges for the dash pod. It sits on 18x9 - 18-10.5 SVE Series II with Flaken 295/40-18 and 275/35-18s. Its lowered and has all new shocks, struts, bushings, etc. Everything underneath is new. The interior is a 8 out of 10 and all stock.
So to maximize the value of the car do i go back with a stock motor with the nice exhaust and cold AC or leave it wearing a carburetor and fix the 331 still with AC?
Both will cost about the same but when you open the hood of a 7-9,000$ Cobra do you want to see a cobra intake and factory EFI with a few bolt ons you can drive every day, get decent mileage, and be ultra reliable? o r a carburetor, a nasty, chops like a mofo idle, aluminum heads 331 that youll have to work on here and there becuase you know youll be beating on it like you stole it?

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CarMichael Angelo said:

In the grand scheme, It isn’t really worth dick with the right engine in it in the first place, especially if it looks cobbled. in 94, the Word COBRA on the back of that car didn’t mean anything more than it did when they put the same word on a Mustang II. ( means “ GT” but with more letters, so Ford could charge more money for it)
I

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CarMichael Angelo said:

If this isn’t a thread looking for advice on how to repair a car, I don’t know what is...
What I wanna know is:
If it has a “ dead miss”. It’s a dead miss. The idle that you think is the cam that you describe as “ chops like a mofo” will be just as impacted there as it is at any RPM if the cam is wiped, or there is a misfire and will directly impact how the car idles.

How can you tell from the way the engine is idling how much lift the cam has? ( answer: you can’t)

A dead hole is an easy diag with a compression tester, and/or a leak down gauge set. In all of your attempts at fixing things by replacing stuff, you never mentioned that you’ve actually performed either of those two tests to determine engine health.
Consistent, even compression pretty much rules out bad rings, bent or burned valves, and.....a wiped cam journal. Furthermore, a leak down test will tell you exactly where ( if any) compression glasses are escaping, either back into the intake, or exhaust ( valve problems) or into the crankcase ( piston sealing issues).

Heres a thought: There are two different firing orders that could possibly be in this mix. It’s a common thing for guys to replace a cam that has been ground for a 351w into a 302/5.0 and rewire it that way instead of the 302 FO. Did you confirm firing order, and figure out which one you should use? I’m gonna guess without ever hearing this that you have an electrical issue here..if not the firing order thing, then an MSD related one.


My advice is
1. learn how to properly diagnose an engine before you start throwing parts at it, or just replace it with an entirely different one.
2. It’s a 94 Cobra, that from your own description isn’t that nice to begin with. ( although it looks pretty decent from the pics) Going through all of the stuff to try and restore it to factory by replacing the engine with an efi version and getting it running properly ( which you’ve already had a problem with the one that’s in the car) isnt gonna do dick for resale. DEPENDING ON HOW DEEP YOU ARE ALREADY IN THE CAR. You said you bought it for a really good price, but now you’ll be in it for at least another 1000, plus labor, plus what ever other sht you have to fix to get it to run right.. How much room do you have to do all of that, and still come out ahead? And if you do convert it back only to break even, you’d be better off finding out what’s wrong with the current engine and fixing it.

In the grand scheme, It isn’t really worth dick with the right engine in it in the first place, especially if it looks cobbled. in 94, the Word COBRA on the back of that car didn’t mean anything more than it did when they put the same word on a Mustang II. ( means “ GT” but with more letters, so Ford could charge more money for it)

If you can get the car to run right as is, cut bait and sell it, or keep it and enjoy the reliability that comes with a properly tuned carb. Right now, if somebody properly converted the fuel system over to carb, it doesn’t have the injection pump in the tank anymore. Additionally, There probably aren’t any cats or O2 sensors in the exhaust either. That car got converted over to carb, because there was a Bone head in its past that couldn’t figure out the efi, or it was full of problems. Going through the hassle to convert it back will be the can of worms the original Bone head was trying to avoid, and the fuel system, and exhaust are going to be part of that.
if you do choose to pull that engine, and after pulling it apart find that you didn’t need to, ( i.e. plug wires crossed) then you’ll know what it feels like to be the first guy.

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