Stalls when hitting gas

[rubio9800]

Hello everyone,

I need some guidance trying to figure this out. When hitting the gas from a complete stop the engine stalls/cuts out or it hesitates
to take off. Best way i can describe it, i’m not mechanic savvy, i know some basic stuff 🙂

This is my first project car

I’ve done the following trying to fix it:

-new spark plugs
-new wires
-new fuel filter
-new EGR valve
-new o2 sensor
-clean carburetor (did not take it out)
-new gas
-fuel system cleaner

Could it be IAC? Bar sensor? Fuel pump?
Carburetor needs adjusting? (idle sounds fine to me)

thank you everyone , i want to fully enjoy this ride 🙂

 

[81Regal]

Possibly the choke not working properly or vaccum leak, kind of hard to diagnose online. I doubt if its a sensor.
Does it run better with a hot or cold engine?

 

[MontesbyE]

Possibly the choke not working properly or vaccum leak, kind of hard to diagnose online. I doubt if its a sensor.
Does it run better with a hot or cold engine?

Does it stall out and then take off like a bat out of hell?

 

[Supercharged111]

I'm confused, you mentioned O2 sensor, carb, and IAC in the same post. Do you have one of those late qjets that trims itself? If so, it sounds like an accelerator pump issue which is what MontesbyE was slowly getting at.

 

[rubio9800]

Does it stall out and then take off like a bat out of hell?

most of the time stalls out , there has been a few times where it feels like it will stall then takes off like a bat!

 

[rubio9800]

I'm confused, you mentioned O2 sensor, carb, and IAC in the same post. Do you have one of those late qjets that trims itself? If so, it sounds like an accelerator pump issue which is what MontesbyE was slowly getting at.

it’s an 81 265 engine , qjet that trims itself? sorry i don’t understand, i believe it’s a 4 barrel.

how difficult would be to replace accelerator pump?

 

[rubio9800]

Possibly the choke not working properly or vaccum leak, kind of hard to diagnose online. I doubt if its a sensor.
Does it run better with a hot or cold engine?

i did not drive it cold , usually let the car run for 5-10 mins before driving .

it has an electric choke i know that, but i don’t know how to tell if it’s working correctly

there is power that is going to the choke thermostat , checked with a voltmeter

 

[pontiacgp]

put a drop or 2 of oil around the alleterator pump shaft and let the oil drain down the accelerator shaft. Leave it for a minute and then start the engine to see if the problem diminishes. If it does then you need a new seal on the accelerator pump.

 

[rubio9800]

this is how i found the choke blade, cold engine.

is that partially open? should it be closed?

 

[rubio9800]

put a drop or 2 of oil around the alleterator pump shaft and let the oil drain down the accelerator shaft. Leave it for a minute and then start the engine to see if the problem diminishes. If it does then you need a new seal on the accelerator pump.

i need to find where it is and i will try that