EK76

In my car search I've come across an 88 firebird formula. I briefly talked with the owner and she didn't seem sure if it was a TPI car of if it had a carb or TBI. I had to be back at work in a few minutes, so I didn't have the chance to look under the hood. I'm assuming its got FI, since you can't legally put a carb on a FI car in this area. It has the original 5 speed and she claimed the original 305 had been replaced by a 350 (but then again, they all say 350). The original badge on the hood said 5.0 fuel injection. From this information, is there any way of determining if this was a TPI car or a TBI car. My understanding is that both engines were offered in that year in the formula. Thanks all!

84redta

iTrader: (34)

Could be anything, formula's came with 305's and 350's, the doors instead of saying FORMULA would say FORMULA 350 as far as i know depending on what they were originally equiped with, and it could be TBI or TPI, if the hood says 5.0 Fuel Injection it sounds like the TBI model, because if i'm not mistaken the hoods said 5.0 HO for the 305 TPIs (correct me someone if i'm wrong) and the 5.7 350 was TPI automatically, but swapping in a TPI system isn't hard but isn't the easiest thing in the word, so it's really up in the air what system it used. My guess on what they did is that they went from a 305 TBI to a 350 TBI, being the easiest swap (just injectors and prom) but i don't know much about swaps, but like i said, there isn't enough information here without you popping that hood!

Tech pages off of the home page will give you all the information you will ever need about the '88s !

zerogsx

All of what say 350?

If you get a chance, you could look at the 8th digit of the VIN to find out what it came from the factory with.

EK76

I mean all of the guys selling their cars with rebuilt engines, they normally try to pass the 305s off as 350s, so you think you're getting some beast. This definately wasn't a 350 factory car. The doors just say "Formula." My old car had the lb9, so I'm not to wild about a TBI car, but perhaps a car that already has a 350 in it would have some potential.

blackphoenix

Easiest way to see if it is TBI or TPI POP the hood
if it looks like a Carb Air Cleaner its TBI - If it has this not 350
If intake plenum has tubular look it is TPI - If it has this possible 350 or 305
As for telling if it is 350 or 305 - That is more difficult. If the girl did not know if it was a TBI or TPI I would not necessarily take her word for knowing the engine size either. I am a girl & know EVERY detail about my car. TBI or TPI is not hard to find out, she should know. good luck. Shenna

blackphoenix

Sorry to say HO was last made in 87 so it would not say 5.0 HO on the hood, factory. the older model Hoods that were HO's did say 5.0HO on them before 87, after 87 they said 5.0 FI which was the TBI model. A simple hood change is not hard or expensive either, it might not be factory hood.
I had a 87 firebird 305HO ( she was sweet)
As for the Formula350 handles, I doubt they went out of there way to match up the handles with the engine swap, but if it was a factory Formula 350 it would have those from the factory, but he said it was a factory 305 converted to a 350. Good luck.

EK76

Either way the mystery will be solved on Friday. I have a bad feeling that the car will have TBI on what is most likely a rebuilt 305.

okfoz

1) THere were NO "HO" cars after 1986 the HO term was used in literature only and referrd to the LB9 engine or L98 engine in dealer books. The label was NEVER used on a Formula from the factory.
2) in 1987 the LG4 would have gotten 5.0 Liter on the Hood and 5.0 Liter F.I. when equipped with the LB9 (305 TPI). STARTING in 1988 and thru the 1990 Model year the 5.0 Liter F.I. Was used on ALL Formula hoods Except for the Formula 350 which did not have a hood decal.
3) Like others have said, the 8th digit will determine what ORIGINALLY came in the car
E= LO3 (TBI) Looks like a carb with the aircleaner
F= LB9 (TPI) Looks like a spider sitting on the engine 8 legs & all
8= L98 (TPI) appears to be exactly like the LB9 BUT it was NA with the M5 Transmission.

Keep in mind that the LB9 with M5 trans on a FORMULA or GTA would have gotten the 3.45 B&W rear axel. It should have 4 wheel disc brakes, and a hotter cam than a normal 305/A4 car. So it might feel like a 350 when getting on it. Proving that it "Might" have a 350 is nearly impossiblewithout disassembly to soem extent and in my opinion would decrease the value of the car, if it was an original LB9/M5 as they tend to be unusual.

Beyond that look for the regular problem spots on cars and if you like it then go for it.

John

EK76

It was TBI...I'm not sure if I should be dissapointed or relieved. My old car had TPI, it was a huge pain in the *** to work on and cost a fortune to make fast, but it sure did look nice. Unfortunately there is no proof that this car actually has a newer 350, since the last owner allegedly had the engine replaced. Everything under the hood looked completely stock, so the only way to find out may be buying this thing. Anyone know how easy it is to put a carb on one of these TBI cars?

89RsPower!

why don't you just get the casting # off the block to find out what engine is in it? Putting a carb on a tbi car is a little easier then putting a carb on a tpi car.. nothing to it really, new intake, a carb, non-cc dist, since its a 5 speed dont havta worry about tcc lockup. Won't pass a visual inspection like that...

Zepher

iTrader: (1)

Putting a carb on there will require some fuel changes, either pull the intank pump and go with a mech one, or get a an adjustable 3 port fuel regulator (I think that is what it is called) since you need to get the pressure down to about 6psi from 14psi.

tpi-hearse

iTrader: (27)

87-up motors on the back of the block on the drivers side(use a flashlight)..it will be stamped 5.7 or 5.0

FormulaL98

check out the speedo man. seeing as how its a original 5 spd car, the tpi 305 should have a 140 mph speedo where as the low output tbi 305 will not. also check or ask for the vin, that will tell u.

89RsPower!

how would any of that stuff help him find out what engine was swapped in?

okfoz

Actually the pad in the rear of the engine on the drivers side with the 5.7 or 5.0 is a great thing, unfortunately you cant see it because of the: wire Harness or A.I.R. System.... THe Wire harness is easy to move out of the way, but the AIR should be bolted on (or nutted on) to the rear of the block so moving it is impossible... Good luck with that one.

The other option would be to remove the AC compressor and look at the stamping on a hog that should have a VIN, plant, some other information that would determine what the engine was originally installed in. From that you could research and figure it out. Its not straight forward, BUT its easier than trying to see the rear of the block in most cases.

John