VinnyX40

Alright here is what is going on i have a 305 h.o from factory it has mild work done to it full exhaust no cat, removed air pump and air tubes, 8mm wires,accel header spark plugs,accel ignition coil,350 injectors,350 fuel pump and timing advavced to 2. Ok for some time now the car will start and rev to 1300 stay there for five minutes and then finally calm down to 520 the car would run it seemed perfect except for the low idle in park and drive so i popped the hood and found a vacuum leak put the hose back on and the idle dropped to 500 while testing the fuel pump went bad so i replaced it and put a 350 pump in instead of a 305 pump and took it for a drive on my way back for driving a little over one and a half miles it the idle started going crazy and stalled started back up and stalled a couple more times got it home and parked it.i started it and the idle in park is bouncing but not stalling left it running for a while and still didn't stall. please help only mode of transportation dont have money for another car

VinnyX40

the car also had the same problems with running before the new fuel pump and finding the vacuum leak

Wife'sCar

iTrader: (1)

I can tell you after just dealing with this myself, 350 injectors are too big, you are running your motor way to rich. Swap back to the 305 injectors. My car came with 350 injectors from previous owner, I had all kinds of idle issues, has to swap back to 305 to get her to idle right.

Wife'sCar

iTrader: (1)

Throwing 350 parts at a 305 will actually make it slower without tuning the computer to compensate.

VinnyX40

that means the 350 fuel pump as well? i was just testing the car i rev the car up to 2500 for a little while and the when i let my foot off the pedal it stalled i ran those injuectors for like four years and it never did this until recently thanks im going to try it thank you very much

Wife'sCar

iTrader: (1)

I think you are fine with the pump, but the computer is programmed for a certain size injector, the injector sprays a certain amount of fuel pure pulse, the bigger injector flows more per pulse, so the computer thinks is the regular injectors and tells it to spray a set number of times, but the bigger injector sprays more each time, making the car run rich.

Before you do anything, try replacing the fuel filter.

You can get the car to run halfway decent with the bigger injectors with some adjusting to trick the car into running kinda meh, but you will loose mpg and a bit of power.

Once the correct injectors are back in if it's still running rough if you have not already I suggest a new cap and rotor.

Did you do the proper procedure of disconnecting the plug on the passenger firewall area before setting timing?

VinnyX40

ive replaced the cap and rotor all ready along with the ignition module coil everything is pretty much new along with the fuel filter as well. when i timed it i unplugged the the timing control set the timing to the mark on what i wanted turn it off tightened the distributor put the plug back on and let the car run for an hour

VinnyX40

with it running i hooked up my scanner it has no ASYNCH pulse and no reading from esc counter or knock damn this is frustrating

VinnyX40

ok the esc counter and knock are working again but now it wont stop running rich and there is still no asynch pulse

Wife'sCar

iTrader: (1)

Never played with a scanner on one of these cars so I can't help you there but I can tell you that you will not get it to stop running rich with the bigger injectors, the only time you can get away with bigger injectors in the 305 without having to reprogram anything is if you have a cam and a few other complimenting mods to the cam. Otherwise the motor can't burn the fuel as fast as the bigger injectors are adding it.