89gt

[calebnumber3]

Hey all I'm looking at picking up my first fox next week. It's and 89 GT 5speed with 71K miles. Car is in super great shape! I don't knwo all the specs of the car but it's a 347 stroker, e303 cam, GT40 heads, edelbrock IM, bigger throttle body and CAI, bbk shortie headers O/R X and flowmasters. The owner doesn't know the specs of the stroker as it was that way when he bought it. Not sure on suspinsion either but it sits super super low. The wheels rub when you cut the wheel all the way to the left or right. Really the only thing I find that wrong with it is the passenger door locking mechanism is gone, and it has issues idling. Owner says from what he can figure out is it needs a tune. Car runs pretty good but you can tell something is a little off it backfires some when you let off the gas I'm guessing just because it needs a retune.

I'm picking it up for 7K seem like a pretty good price? Also just so wondering what kind of power it will more than likely put down once its tuned? Also once I get everything straightened out I'm wanting to throw some N2O at it wondering what a good size for these older engines are?

Thanks in advance guys I'll post pics when I get the car!

Pic of car:

 

[FISHTAIL]

Nice car. Shouldn't need a tune, though one always helps. Power, even with a 347 is being hampered by the heads. Ditch the GT40's immediately and get something better (Trick flow or AFR would be my first two choices). The idle issues could be many things. IAC sticking, crappy MAF, crappy MAF position, vacuum leaks, etc.

The backfire after letting off sounds like the car could be loading up..which also could have varying causes, but one that springs to mind as related to a crap idle is the MAF. It could cause both of those issues.

Top priority should be to know where everything is set. Make sure your fuel pressure is at 39-40psi (engine on, vacuum off the regulator), check your timing (12-14 btdc is generally where these cars like to be, 10deg is stock), check the overall condition of the plugs/wires/cap/rotor. Make sure it doesn't have any vacuum leaks, etc.