Car Sputtering when driving

[CALI-WAGON_09]

just thought i would give my 2 cents , been a mechanic for 20yrs and this is a common problem, i would check the fuel pump and fuel filter. this is usally a sign of a fuel pump going bad.

Brand new fuel pump and filter any other suggestions? :idea: car use to have a charcol canister and i did't plug the line does that make a difference? also can u tell me the degees for timing on a 305

 

[houndin101]

just thought i would give my 2 cents , been a mechanic for 20yrs and this is a common problem, i would check the fuel pump and fuel filter. this is usally a sign of a fuel pump going bad.

 

[houndin101]

:shock: Yep I have the same problem with the peddle too, and yes after i drive a little while 30mins or so then have to restart it is hesitant to start. When the car is cold fires right up also yesterday went to the store(down the street) at a slow cruise when it shifted to second it started backfired lol is that about?????[/quote]
mine gives me hell starting all the time...and backfires only caused by too lean of a mixture or timing is a good bit off.........Brand new fuel pump and filter any other suggestions? car use to have a charcol canister and i did't plug the line does that make a difference? also can u tell me the degees for timing on a 305..........
the line was suppose to go to the carb bowl right...i jus plugged mine it didnt change anything but i did it jus to be safe...and look on your catalyst on the radiator shroud thats where i found mine...for the 350's its 8 degrees at 600rpm

 

[taab123]

timing should be anywhere between 8 and 10 btdc. just make sure that you dont have a vacum leak. and a very simple problem is water in the fuel run some into a glass and let it sit and see if the water beads seperate. or run your fuel pump line into a tank of gas and draw from that. usally a stumble doest just happen unless something changes drastically. also have you thought about your catalitic convertor.

 

[houndin101]

timing should be anywhere between 8 and 10 btdc. just make sure that you dont have a vacum leak. and a very simple problem is water in the fuel run some into a glass and let it sit and see if the water beads seperate. or run your fuel pump line into a tank of gas and draw from that. usally a stumble doest just happen unless something changes drastically. also have you thought about your catalitic convertor.

i've got my timing set at 8 degrees but im thinking about advancing it to 10 and i had a vacuum leak but i put a temp fix.im about to replace the temp fix here soon...and no water in my fuel

 

[jae]

Yep I have the same problem with the peddle too, and yes after i drive a little while 30mins or so then have to restart it is hesitant to start. When the car is cold fires right up also yesterday went to the store(down the street) at a slow cruise when it shifted to second it started backfired lol is that about?????

When you state "hesitant to start" do you mean slow cranking speed? If so that could be high resistance in your cables, or starter heat soak. If your cranking speed is fine, if you tap the gas before cranking the warm or hot engine does it start right up as it would when cold?

For the carb / fuel delivery do you have this stumble with the vehicle in park? While in park idling and you rev it, do you have the stumble right off idle? Have you cracked the throttle open by hand, or had a buddy press down on the gas pedal and observed the fuel flow while running?

Have you tried, as a test, running the engine w/o the filter and took it around the block and saw what happened? While the filter may be new it could be a restriction. But I think the 750 is too big for the engine and think it'll be happier with a 600, maybe even a 500cfm? Remember the Edlebrocks have pretty good sized primaries, and along with the nice-sized jets you may be getting too much fuel. And you're only going to be able to "lean" it so much and leaning too much will cause other problems.

But I would fix that vacuum leak first, especially if it's carb / intake related.

 

[CALI-WAGON_09]

timing should be anywhere between 8 and 10 btdc. just make sure that you dont have a vacum leak. and a very simple problem is water in the fuel run some into a glass and let it sit and see if the water beads seperate. or run your fuel pump line into a tank of gas and draw from that. usally a stumble doest just happen unless something changes drastically. also have you thought about your catalitic convertor.

OK I have a guy with a vacum tester he's going to check for leaks and i'm going to check the gas thanks. Also i don't have cats true duals into flowmaster 40 series with turndowns out of the muffler(looked around muffler there are some bad welds going to get it fixed this weekend)

 

[CALI-WAGON_09]

Yep I have the same problem with the peddle too, and yes after i drive a little while 30mins or so then have to restart it is hesitant to start. When the car is cold fires right up also yesterday went to the store(down the street) at a slow cruise when it shifted to second it started backfired lol is that about?????

When you state "hesitant to start" do you mean slow cranking speed? If so that could be high resistance in your cables, or starter heat soak. If your cranking speed is fine, if you tap the gas before cranking the warm or hot engine does it start right up as it would when cold?

For the carb / fuel delivery do you have this stumble with the vehicle in park? While in park idling and you rev it, do you have the stumble right off idle? Have you cracked the throttle open by hand, or had a buddy press down on the gas pedal and observed the fuel flow while running?

Have you tried, as a test, running the engine w/o the filter and took it around the block and saw what happened? While the filter may be new it could be a restriction. But I think the 750 is too big for the engine and think it'll be happier with a 600, maybe even a 500cfm? Remember the Edlebrocks have pretty good sized primaries, and along with the nice-sized jets you may be getting too much fuel. And you're only going to be able to "lean" it so much and leaning too much will cause other problems.

But I would fix that vacuum leak first, especially if it's carb / intake related.

When I say hesitant it cranks fine but seems like it takes a second to get the fuel up there. I havent tried tapping the gas i'll let u know about that. I will also try the no filter test too. yes it does stumble off idle in park but only sometimes and the same thing the other guy said about tapping the gas and the car wanting to die out i have that problem too

 

[CALI-WAGON_09]

timing should be anywhere between 8 and 10 btdc. just make sure that you dont have a vacum leak. and a very simple problem is water in the fuel run some into a glass and let it sit and see if the water beads seperate. or run your fuel pump line into a tank of gas and draw from that. usally a stumble doest just happen unless something changes drastically. also have you thought about your catalitic convertor.

i've got my timing set at 8 degrees but im thinking about advancing it to 10 and i had a vacuum leak but i put a temp fix.im about to replace the temp fix here soon...and no water in my fuel

my timing is 10 degrees also. What was the vacum leak?

 

[houndin101]

timing should be anywhere between 8 and 10 btdc. just make sure that you dont have a vacum leak. and a very simple problem is water in the fuel run some into a glass and let it sit and see if the water beads seperate. or run your fuel pump line into a tank of gas and draw from that. usally a stumble doest just happen unless something changes drastically. also have you thought about your catalitic convertor.

i've got my timing set at 8 degrees but im thinking about advancing it to 10 and i had a vacuum leak but i put a temp fix.im about to replace the temp fix here soon...and no water in my fuel

my timing is 10 degrees also. What was the vacum leak?

a piece at the back of the intake manifold...i line goes to it and there was a hole in the top of it...when i get the money im replacing it