Alright guys. You have been a huge helps so far, thanks a bunch! Anyway, on with the problem. I have a 1989 Firebird, 305 TBI. I have cleaned and put all new gaskets on the throttle body, new plugs, new wires, new fuel filter, and replaced the fuel pump. You can get up to a steady 55-60 mph, and you can feel the car (what I would call sputtering) I guess if I had to draw you a mental picture, it feels like the injectors are just sparadiclly spraying, kinda like pumping fuel out, real fast! And you can feel the car shuttering like real fast like.

Another thing "sometimes" when I slow down real fast, like to turn in a driveway, the car will stall and cut off, but it always cranks right back up. So what would be my next step? What to buy, what to troubleshoot next. Thanks again guys, you have been a big help!

 

that stalling and cutting off is probably the fuel pump pickup being exposed. Mine does it constanly because i dont beleive in putting anymore than 5 dollars of gas in at any one time (goes like 75 miles on that splash of gas). See if it does it wile taking a (right??) turn real hard with a full tank of gas. As for the shaking, do you hear the engine misfiring or does the car just shake at high speeds. The driveshafts in these cars are notorious for causing high speed shaking because they are so poorly balanced.

 

Yes it will stall out if the gas tank is full or empty. And the shuttering isn't like a vibration of something being out of balance...it feels like it getting ready to run out of "real quick" then it will pick back up, but it's so fast it's not like it back fires or starts to cut off. It just feels like the injectors are dirty and at times the gas can't get through there. But I have cleaned the injectors good, and I have put injector cleaner in it. ????

 

I suppose it could be the fuel pump starting to go out. Try checking the fuel pressure and see if it fluctuates or not.

 

Mine shakes too. I hope to track down the problem soon. I'm NOT looking foward to that job.

 

Luckilly for me my fuel pump died right in the driveway... funny it took me to school and back home that morning without issue... then when in the driveway.. sputter.. and dead...

 

SAVED BY THE GRACE OF THE CAMARO ***!!!!!!!!!!!!!

 

mine is doing the same thing and i just replaced the plugs, wires, fuel pump, fuel filter, cap and rotor, and some other stuff, and still don't know what the deal is. my problem may not be the same as yours but i was wondering if anyone had a clue about mine. here's the deal: the car runs a lot better after the tune-up, but when i hit 55-60mph or a little faster the whole car begins to shake, not like a rattle or like something is unbalanced, but the engine just gives out and then goes back really fast causing the car to hesistate? (hard to explain). it continues to do that for a while then quits, starts again, and then stops when i slow down. not really sure what it could be, some people say the tranny, but i was wondering if the rotor of cap wasnt on right if it would cause that because something was wrong with the rotor when i took it off and it wouldnt go on right, it was like stuck, but i got it aligned properly. any help would be great, thanks.

 

im having the same problem at 50-60mph. Check the injectors. In my case, I swapped in a 350 but kept my 305 injectors. It hesitates due to the lack of fuel. Not sure if that applies to you since all you did was normal maintenance. If youve gotten a new perf chip or heads and what not then you might be in need of more than 45pph injectors.

How does the car run while idling...is it rich or lean.

 

it runs pretty rich with no problems, except for when we first did the tune up, the the cap started to shake pretty bad, wasn't on right, but thats fixed. i'm going to replace the rotor and cap again and check over everything again, and see what that does.