Hello everyone.

I was recently asking for help with my distributor and thanks to your answers I found the courage to take it apart.
I got it cleaned up, put it back together and itīs working now. Thank you for the help.

My 1964 Starfire is still not working. I seem to have a problem/problems with the carb.
I have had it apart for several times now, adjusted float levels according to shop manual and I believe theyīre correct.

What happens is that I can somehow get it to idle quite smoothly but if I give it throttle fast it stalls.
I can get the rpm up to 3000 and hold it steady for 20-30 seconds and after that it just suddenly bogs and usually stalls
if Iīm not fast enough to let go of the throttle.

Took the carb off once again and adjusted floats. Put it back and the car flooded. Gave it a few slight knocks to the side
with a hammer and got it idling somehow.

Decided to check fuel pressure. Book says 5-6 psi for normal operation. Mine is putting up 9 psi.
Fuel pump has not been rebuilt. I couldnīt believe the old pump was giving 30% more than it should.
I thought they just got old and weak.

Could this be the root of my problems? Is it flooding and stalling because of the high pressure that the needles canīt handle?
Should I try putting in an electric pump and a regulator? My friend has a pair extra.
Guess I will repair the pump anyway, just donīt have the money or the time right now.

Appreciate all answers.

- Ville

 

My experience with a fuel pump that had too much pressure was flooding at idle and steady cruising speed. I had to rev the engine to keep it running. Since there was so much fuel pouring into the engine, I had to open the throttle to let more air in to balance it out. And yes, the higher pressure would push the needle off the seat and let too much fuel flow.

 

Rockauto shows a brand-new Spectra Premium fuel pump for a '64 Starfire for $35 plus shipping. Amazon has the same thing for $44, but the shipping is free if you're a Prime member. Why not just get a new one and put it in?

 

I just went through a similar thing with my '68 4-4-2. When I would start the car, it would idle fine for 5-10 seconds and then just start to load up and burn rich. If I went down the road, the rich black exhaust smoke would clear up and the car would run fine. At idle, though, it would just load up again. This had been happening regularly for 7 years. The carburetor had been apart and rebuilt and readjusted several times to no avail. I completely discounted the fuel pump as I figured it either worked or it didn't work and, in this case, it was working.

Trouble was, it was working too good! A mechanic friend of mine suggested we check the fuel pressure from the pump to the carburetor and it was 10psi! The book says my quadrajet will handle 5-7 pounds and a qjet expert I know says the max a qjet can handle is 7.5psi. So, I bought a new fuel pump, put it on, measured the pressure at 5.5psi, and the car runs better than it has ever run. The carb doesn't load up anymore, the engine idles consistently smooth without blowing out the rich, black exhaust it had previously been doing, and it runs great going down the road. And, I might add, the gas mileage is better!

So, the problem just might be your fuel pump.

Randy C.

 

As a point of information, the OP is in Finland, I think.

 

Thank you for your answer, but RockAuto shows wrong, the car is a 394ci.
They donīt offer a mechanical fuel pump for the car and I would like to keep the car original.
Thatīs why I can have a pump and regulator from a friend to try with.
And yes, since I live in Finland, that pump ends up costing about 100-110€ with shipping and tax.

-Ville

 

This part makes me think you need a new accelerator pump.
I can see the accelerator pump giving a squirt when operated. I guess it doesn't affect things anymore when holding throttle steady at 3000 rpm.

I need to explain this with more detail. Hope Iīm using the right terms and not misleading your precious knowledge and time in this matter.

Maybe "stalls" is a wrong term. When the car is stationary (in neutral) and Iīm using the throttle manually by hand, the car revs nice at about 2500-3000 rpm for approx. 20 secs and then just all of a sudden it completely dies. I might be lucky and keep the car alive if I pump the throttle by hand.
Usually it just dies. Starts again fine. Idles quite ok. Then I can repeat this same pattern with same results.
Last time doing this over a few times ended up with the carb flooding.


The timing is ok and I have spark all the time and until the end.

Is there a Rochester 4GC manual somewhere to be downloaded? Iīd like to know how the power piston is supposed to work.
Would like to take it off the carb lid. Seems to be sitting in there quite tight?
Power valve itself seems to be working, at least itīs moving. Could it leak (so much) that this could happen?

Going to try the electric pump + regulator tomorrow.
Will keep you posted after changing electric pump.


Thank you for all replies!

 

I have a jeep that had too much fuel pressure and all it did was smoke when idling for a long time. I think your problem is the metering rod needs adjustment and perhaps the air/fuel adjusted. You wouldn't have to get an electric pump, you could just get an inline fuel pressure regulator. The jeep is suppose to have 4 psi and the mechanical pump was putting out 8.

 

 

Thatīs correct, new seats and viton needles.
I have the shop manuals 1-5. Just would like to have some more detailed information on adjusting and troubleshooting etc.
No, not the accelerator pump. In my opinion on the lid thereīs something called a power piston or vacuum piston which operates the power valve which lets more fuel in the chambers.
Found some Mikeīs Carburetors videos on Youtube, he called it power valve and piston and he was not talking about the accelerator pump.
As above.
Yesterday put in a new Holley regulator (4 1/2 - 9 psi). I couldnīt get a steady reading with my fuel pressure gauge. Tried to adjust it down to 6 psi.
The gauge may be faulty. Iīll try to get my hands on another gauge and see what the reading is.

Thank again, the journey continues.

 

I'd contact Holley tech and ask them for advice.

 

What brand carburetor is on the engine ? I was thinking it was a Rochester 4 GC.

 

Does the car run better with the regulator... (with the mystery PSI fuel pressure) ???

 

It is a Rochester 4GC. The fuel pressure regulator is a Holley.