Hello everyone,i have a little bit of a problem with my firebird, its a 1992 with a 305 tbi. well when i got the car i noticed that i could not even spin the tires in it, and it was much slower then my last firebird with the same exact motor, and the crazy thing is this car has a posi rear my last car didnt.the main problem is that when you give the car gas its seems like its choking it like its out of gas almost, i start the car put it in reverse step on the gas and it almost turns off!, i have changed the ingnition system to 8.8mm wires mallory cap and rotor button and a performance coil, still no power change or spinning of the tires, also sometimes at a light i can smell gas, and sometimes when i rev the engine high you can smell it, i have check all the filler hose and such no leaks. i got told by someone that its probably my Fuel pressure regulator, i changed the fuel pressure reg on the top of the throttle body still doing the whole stutter splutter, its not all the time but enough for me to need to find the problem whatever it is i have a funny feeling that this is the problem with the power. i dont know if this will help you figure it out but everytime i put my foot into it at a light i never know how the car is going to respond sometimes its very very slow taking of and other times its very decent but it varies alot. i only use 93 octaine and try to keep an octaine boost in it. any suggestions. i need to get this figured out i am also getting 12.5 miles to the gallon!!!! its terrible and its 12.5 no matter how i drive baby it or stomping on it, or on the interstate. there are no check engine lights, and no visable vacuume leaks but please give me your advice i am willing to do anythign to stop the shudder and splutter and have the power that the car should have. sorry for the rambling .

 

1) Replaced plugs?
2) Replaced fuel filter?
3) Injectors firing a nice spray pattern?
4) Check timing


Spinning Wheels? No 305 TBI will just spin off a stop - at least not an auto - not without powerbraking. Spinning wheels or not is not really an indicator of anything.

Mileage is though. That car should get almost 30mpg hiway - so something is off.

Start with basics. If it were real involved, there's be a code thrown more than likely.

 

Everything yes except timing I know spinning doesn't do anything if anything u dont want spin u want grip but my last 5.0 tbi would spin and smoke tires all day.this has me confused

 

my 16.7 second L03 automatic will smoke the tires without a brake stand, well not smoke them, but definitely spin like crazy for atleast 5 feet

are you getting any trouble codes? or even a 12 being flashed?

 

no codes no lights, at first i thought the guy i bought it from may have taken the check engine light well service engine soon light bulb out but he didnt bc when you just turn the key one click foward it comes on along with the other lights, so no codes are being thrown which is the weird thing, makes me think its not a sensor, and i have chaged the fuel press reg, plugs wires cap rotor button, and coil , and still nothing no spinning and still have a shudder when i accelerate some times, very weird and annoying bc when im at a light and someone wants to race i never know how its gonna act it might take off soo slow a chevy malibu would smoke me, and other times ill keep up with the big dogs off the line well for a short time kinda not really but you know what i mean

 

maybe try an ecm from a junkyard(or parts store if you have the money)

when i first got my camaro it acted weird, turned out the ecm was shot, and i never got a "bad ecm" code, not saying thats your problem, but if you can find a cheap replacement or know anyone who would let you borrow one it wouldnt hurt to check

 

i mean its worth a try if i can find one in a junk yard, i would have to have one for tbi, and it would have to have all the power windows mirrors all that jazz too right? or can i just take one that has a tbi 305? if that doesnt work any other ideas i was gonna get someone to check and advance the timing maybe other then that i have no clue

 

just match the service number on your current ECM to one in the junk yard, can be out of a truck or car as long as the service number's match, you will need to put your prom chip into that ecm then plug it in to your car

no need to worry about power windows or anything like that

i know for the 89 L03 the ECM is the 8746 found in cars trucks and vans with the 5.0 tbi motor, yours is probably different because its a 92 but you should still be able to find one in another car or truck