350 wont start unless jumped and popping out of the carb ONLY at start up!

[ruedger455]

Well another problem with my gmc. Well when i try to start it up for the first time of the day, it just cranks and cranks like it wants to turn over but it will crank till all i hear is a repeated clicking sound. And then when i put it on jumper cables it will start but only when i pump the gas pedal an ungodly amount of times. And when it starts to get ready to fire up, the carburator spits out a puff of gas or smoke through my air filter. It sounds like someone is actually spitting. And when it does that it dies! I have to do that about 10 times before it fires up. Im lost on what to do!!

 

[ruedger455]

And when it fires up it just sputters and i have to give it gas until the motor warms up then it runs like a champ and no back firing of any kind and no hesitation.

 

[HotRodPC]

Sounds to me you might have a weak fuel pump, AND/OR a bad accelerator pump in the carb. It does certainly sound like a fuel problem. To know for sure, drop about a tablespoon in the throat of the carb and it starts right up, then you'll know for sure.

 

[ruedger455]

Ill try that. I think i want to swap out the edelbrock for a holley. But ill try the gas in the carb trick.

 

[ruedger455]

When i take the air filter off and open the throttle by hand with the motor off it shoots a pitiful stream at first but then the further i open it up it just kind of dribbles out.

 

[r.booser]

mine did the same exact thing after I installed a brand new carb. An my fuel pump seems to be running fine. I adjusted the timing and carb and that seemed to fix my problem.

 

[ruedger455]

What did you do to your timing? And your carb?

 

[r.booser]

well my truck doesn't have timing marks. So I just turned the dizzy to where is sounded and ran the best. To adjust the carb I just turned the front two screws to tune it in. Now if this is a new issue you just accord I wouldn't go messing with your timing. But had just replaced the dizzy and carb so mine needed it. Is this a new issue on a daily driver?

 

[r.booser]

I just saw the clicking part, have you checked your ground? I know in the past on other vehicles it has done that with a bad ground if the battery isn't dead. Check your connections and wires.

 

[ruedger455]

I just bought the truck 2 weeks ago and they guy said he had to pump the gas to start it. It also has an electric choke thats not hooked up. Hes got it zip-tied open. Could this cause the plugs to foul out faster.

 

[HotRodPC]

No it will not, but pumpling to much and getting to much fuel will flood it. Now you mention fuel drippling out, and steam. That makes me think you might be flooded and have stuck floats or debris in the needle and seat. For a flooded engine, you hold the gas pedal to the floor, DO NOT PUMP IT, but hold it to the floor until it starts then gradually let it back up so the RPMS don't get so high you blow your motor. Does sound like you have some carb issues byt timing can too be an issue. Might be a combo of problems.

 

[r.booser]

No it will not, but pumpling to much and getting to much fuel will flood it. Now you mention fuel drippling out, and steam. That makes me think you might be flooded and have stuck floats or debris in the needle and seat. For a flooded engine, you hold the gas pedal to the floor, DO NOT PUMP IT, but hold it to the floor until it starts then gradually let it back up so the RPMS don't get so high you blow your motor. Does sound like you have some carb issues byt timing can too be an issue. Might be a combo of problems.

Well put, PS never trust anyones work. I bought a truck a month ago that sat for a year. I've replaced, dizzy, wires, plugs, carb, heater core and next is the gas tank. I've found so much idiotic things this guy did no wonder he couldn't get it running.

 

[ruedger455]

Yea i threw a timing light on it and my notch on my balancer is not under any of the notches on the timing tab. Its about a quarter inch towards the passengers side. My timing tab sets at about 1 or 2 oclock. I had it running at the second point past the big notch which i assume is 0 so i would have been at 4° but my idle would jump all over getting high then dipping down really low. And everywhere i set it, it pops out of the carb when i try to push the gas pedal fast. The blue mark is where my mark it when under the light!

 

[ruedger455]

When i first checked it with the light the mark was at the 12 oclock position.

 

[HotRodPC]

Are you 100% sure you have the correct timing tab? Are you 100% positive the timing chain marks were lined up dot to dot on the money? New Chain and motor, you should be able to time it with a light and have it be accurate.