Hi everyone,
My car is actually running quite well and even idles nice and steady. However, I made the mistake of taking it to the dyno and learned that it is pretty lean at WOT, that is up till 4000 rpm.
In the 2000 rpm range it's 15.5 - 15, then about 3300 it goes to 14 and finally at 4000 rpm it richs out to 13.5 and stays there. I'm looking for any ideas. The dyno guys say get a custom tune, like a Diablo chip. However, I'm short on cash for the rest of this year and looking for tires too. Any ideas would be greatly appreciated.
I'd scan it for codes, before throwing any money at it. You could try the free stuff, like cleaning the Mass Air sensor and maybe the O2s.
What mods are on it?
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1992 Deep Emerald Green Mustang GT Hatch, 5 speed, 2.73s, Mac fenderwell cold air intake, '93 Cobra MAF, Mac 70mm throttle body & spacer, Explorer intakes, Mac unequal headers & offroad pipe, Magnaflow catback, Walbro 110lph fuel pump, Jet adjustable FPR, MSD Blaster coil, Accel 8mm wires, FRPP aluminum quadrant, UPR firewall adjuster, stock cable, Granatelli upper control arms.
Waiting to go on: Granatelli lower control arms, and GT40 Iron heads!
Well, as usual, I haven't even thought about covering the basics, ie: cleaning the MAF or O2 sensors. Thanks for your ideas!
Anyway - mods: CAI, 75mm MAF, 70mm TB, RPM II intake, cast GT40 F1ZE heads, E cam, A9L computer, long tube headers, MSD dist., 1.6 SVO roller rockers, 24# injectors. That's all I can think of right now on the motor. However, last year I ran the 1993 Cobra computer with Ford's 70mm MAF and it was a solid 13.5 all the way through the rpm range. Only things I changed this year are the MAF, A9L, 1" intake spacer (I have a Cobra R hood) and adjusting of the idle and TPS. By the way - the new combination picked up 10 RWHP and 15 lbs of torque over last year's Cobra set up.
Actually, I have a 75mm Granatelli MAF, not a C&L. Interesting choice of words - "confusing the computer" as that's exactly what the dyno guys said I was doing. Hence the reason they want me to purchase a Diablo chip and some tuning time. Now, I thought the whole reason behind purchasing a MAF calibrated for my 24# injectors is to make it nice and happy with the stock A9L computer?
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1988 LX 5.0 5spd Moonroof
Tri-Ax shifter, CAI, 75mm Granatelli MAF, BBK 70mmTB, 24#, BBK fuel press regulator, RPM II, E cam, Ford Aluminum GT40X heads, Comp Cams push rods, 1.6 SVO rockers, Electric fan, A9L, Diablo Revolution chip, BBK long tubes, 2.5" X pipe Magnaflows no cats, Auburn 3:73 gears, Strange axles, lowering Ford C springs, bump steer kit, BBK rear control arms, Eibach sway bars, sub frame connectors. Cobra R hood. 140mph Speedo. Dynojet = 287rwhp & 302rwtq.
Ah, see, that's exactly what I thought. I should be good to go.
Since I bought the A9L used (my car is a mass air conversion), maybe I bought a "bad" one. I don't know of any better way to test than to continue going back to the dyno at $50 / shot. Eventually, I'll be better off to just get a custom chip and tune and let the tuner account for any shortcomings (if possible). It's a little frustrating.
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1988 LX 5.0 5spd Moonroof
Tri-Ax shifter, CAI, 75mm Granatelli MAF, BBK 70mmTB, 24#, BBK fuel press regulator, RPM II, E cam, Ford Aluminum GT40X heads, Comp Cams push rods, 1.6 SVO rockers, Electric fan, A9L, Diablo Revolution chip, BBK long tubes, 2.5" X pipe Magnaflows no cats, Auburn 3:73 gears, Strange axles, lowering Ford C springs, bump steer kit, BBK rear control arms, Eibach sway bars, sub frame connectors. Cobra R hood. 140mph Speedo. Dynojet = 287rwhp & 302rwtq.
Need help with car running lean 
