I picked up this 92 firebird @ 3 years ago. Smog checks are getting closer to fail each check. TBI on the 5.0 is looking poor. I get @ 10 MPH in town, and with the "Tornado" 23MPH on the freeway, (including rush hour traffic). The engine wants to fall on its face, off the line, unless I set the timing to 6* adv (Especially when cold). Beyond getting a dual snorkel intake, what can I do about max HP, fuel economy, and stay away from the smog Ref station in Ca.

Brakes are a problem also. No- LE system, disc in front, and drum in rear. What to do? I jacked the car up in the rear and let the engine idle in gear, apply the brake pedal and barley stopped the rear wheels. Front disc warp easy and heat check. I'm not looking to do constant road racing, but I'd like to get more than 15K out of a front brake job. Getting close to new car stopping distance would be great too. Help?

dnot67

 

Welcome aboard!

It sounds like your car is in dire need of a tune up. Your car should run much better than that. With a tune up you should replace the following parts

Spark plugs
Plug wires
Cap
Rotor
Fuel filter
02 sensor

Also, take that tornado thing and dump it into the trash. That is where it belongs. It is most likely hindering your air intake. How many miles are on the car? With a tune up your car should run as good as the day it was new. You should see 25+ mpg on the freeway and much more than 10 on the street.

 

i vote for trashing the tornado.

 

Now is your chance Mr. Chesterfield from California. What have you done for your car that maintains your performance and economy?

I keep a good tune, stay on top of clean fluids (constant stop and go in the Bay Area) and I've messed with my ECM (had someone burn me one). Car is running solid (for a 305) and picks up nicely on the highway. As for economy, a trip to LA will determine if the chip was bad or good for my economy.

Basically, no one knows the LO3 better than Shifty though. Start with the tune. Your 92 should be well equipped to pass emissions in CA with a good tune and operatable emissions equipment.

 

First I'd like to thank all of you for the responses. "Thanks!" And then go on to say, I just did the tune up to try to pass smog. New air pump, O2 sensor, Cat converter (did not pass the first time). New water temp sensor, thermostat (195*), rad hoses and cap, water pump (was leaking), new radiator, serp belt and tentioner. Borg Warner select rotor, and cap, Borg Warner Select supper Mag 7MM wires, Bosch Plat plugs (single electrode), AC air filter, PCV, filter for charcoal canister, breather filter, fuel filter. Fram oil filter. Distributor module, coil (yellow spark), idle solenoid (cold starts w/ high idle), new vac hoses. I sprayed for poss. leaks at manifold and injection body (no change in idle). Filled with Mobil 1 10w 30, 50 -50 Prestone. New alternator and battery (12 volt charge and 1 dead cell), air cond compressor, receiver dryer, inline chunk filter (dry system), struts, tires, (ok A/C, struts & tires don't count for tune up), set timing for 3* adv. (to pass smog, cause a 0* heavy hesitation off the line.) I was getting 18 on the freeway before the "Tornado" now 23 W/. (If the road is wet, I can't get the rear end to hook up, lots of scary Posi sideways action.) I barley passed smog. The car's odometer says 130 thousand. Your guess is as good as mine. Cylinder compression measures within 4 lbs of each other, and averages 5 lbs. from new spec. Did not do wet test due to "no" smoke out the pipes, and 3000 miles w/ 1/2 quart low.

 

"Now is your chance Mr. Chesterfield from California. What have you done for your car that maintains your performance and economy?"

You can call me chesterfield, no need to be so formal.

 

I got nothin' on Dewey, JP, dimented, and kdrolt



You may want to change your CTS (coolant temp sensor) while you are at it. It is located at the front of your intake manifold next to your thermostat housing. A bad one can cause your ECM to dump fuel into the motor thinking that the motor is running cool.

EDIT: You can also test yours if you have an Ohm meter. You can use hot and cold water with a thermostat to record the resistor in the sensor at various known temps. A quick search will bring up that chart that has the CTS values.

 

Could this be a problem?

 

Put your timing back up to stock it will run so much better. Just turn it down when you need to pass the sniffer. Full exhaust would be my first reconmendation for your call after a tune up. Headers new cat and a catback exhaust will really wake your car up and you can get better mpg out of the car if you can keep your foot out of it.

New cat can help with emmisions also.

 

If you're running the factory a/c and smog pump a dual snorkel intake will not fit without plenty of fabbing.

 

He's got the timing Advanced 3*. That should be fine, tends to smooth out these engines because they have such weak timing curves stock. You're definitely right about exhaust though, should be a first mod.

 

If you want to use the dual snorkel (like i just did)....it will actaully fit, but the passenger side snorkel tube comming out of the port will be crunched down between the hood and the diverter valve...i removed the diverter valve and it fit nicely...but as long as you can use tubing that can handle the "sqeeze," you should be ok