ok i don't really know of any good site that has information about Formulas, and the TGO tech data wasn't very helpful..

someone brought in a Formula today into my auto tech class for some repairs. and i looked at it and was trying to figure out what year\engine combo etc it was... i looked at the vin. and i looked at the 10th digit and it was an L i believe. (the 10th is the one to look at for the year right?) which i thought was a 90 model? it also had the different front end, with the foam soft black thingys in the font end. which i thought they didn't start until 91? and it had shoulder seat belts in the rear. and the buldge good that said 5.0 EFI on it.. and the steeringwheel was aftermarket so i don't know if it came with airbags or not. but what confused me was when we popped the hood and it had TBI.. i thought all formulas had TPI especialy a 90+ model?? i wont see this car until monday. and i was curious what it could be and why it had TBI.. i could always write down the VIN on monday, if its still there. but im just anxious..

thanks

305 TBI is the most common motor in Formula's. The TPI was an option.
Check out www.theformulasource.com for all the info you need!

Peace

All the cosmetics sound valid for 1990 except the rear shoulder belts.. I don't know what to make of that; then again I've never owned a 1990 myself.

TBI Formula does not sound unusual, but I don't know about 1990 specifically. get the 8th digit of the VIN. Should be an "E" for 305 TPI or "8" for 350 TPI. I think those are the only 2 options for 1990 Formula.

At least according to https://www.thirdgen.org/newdesign/tech/techdb.shtml, but then I never trust those pages anyway.

no, for a 305 tpi, the 8th digit will be an "F"

for a 350 tpi, the 8th digit will be an "8"

Rear shoulder belts started in 89,TBI was the base engine for the formula

Mine is an 89 and being a drop top, the rear belts are lap only, no shoulder!

Could that be modified? Also, FYI, the 1991 and 1992 have the Banshee/Batman style grill/nose.
Prior models had black vinyl rub strips like mine. Except Trans ams and GTAs

Bill

89 History

The Easiest way to tell the difference between an 88 & 89 is the Back Seat Shoulder harness'. 88 did not have them whereas the 89 Did. The 89 Firebirds dropped the subwoofer option.

The Formula also got new P245/50ZR16 tires as standard. Also this was the first year with the "Pass Key" option, (second year for GTA) it was now standard on all firebirds.

The Engine received only a minor upgrade to where the Cold Start injector was eliminated from the driver side of the intake.

The 89 Formula started life with a 5.0 TBI Engine, A/C, Aero Spoiler, "Dome hood", Formula Graphics, WS6 Suspension, P245/50ZR16, two tone paint & striping, & HI-tech turbo "deep dish" aluminum wheels



Option Group 1SA included: A/C, Body Side Molding & Lamp Group, power windows & power Locks

Option Group 1SB included 1SA &: 4 way Seat Adjuster, Cruise, Power hatch release, remote Mirrors, rearview mirror with reading lamp.

1989, was the first year that the Trans Am could not be ordered with the TBI engine, The T/A automatically got the 5.0 TPI engine as a base.


1990 was the first year for an Airbag in firebirds, it was standard on all models, and could not be deleted. The TPI engines also received a change, gone was the MAF (mass Air Flow) system and a new MAP (Manifold Air Pressure) or (Manifold Absolute pressure) took its place.

All Formulas received at least the following:

power brakes, center stop lamp, Instrument panel, Center Console, Front Air Dam, Gages, Hatch Pull down, hidden headlamps, Pass Key theft-deterrent system, AM/FM radio, Seat Belts Front & rear, Side window defoggers, Soft ray tinted Glass, Air Bag, Lockable rear Storage compartment, 5 Speed Manual Transmission, Wet-Arm Wipers, 5.0 Liter TBI engine, A/C, Aero Spoiler, "Dome Hood," Formula Graphics, WS6 Performance Suspension, P245/50ZR16 Wheels with Hi-Tech Turbo aluminum (deep dish Wheels)


from www.3rdgenformula.com