another stumbling into secondaries question?

[mreid]

Not to side track this too much, but that was one of the things I hated about NJ, you can't pump your own gas. Many times they would rather have me do it than screw up and get gas on the paint or worse.

Back on topic. Does your car have a fuel return line to the tank? Is it an electric or mechanical fuel pump?

[D111]

Originally Posted by mreid

Back on topic. Does your car have a fuel return line to the tank? Is it an electric or mechanical fuel pump?

not sure about fuel return line, it has a electric fuel pump.

excuse me for not knowing much about the car, I've only had it barely a month and it's my first cobra .

[jhv48]

I believe you have a Holley Street AVenger carb. Thus, vacuum secondaries, and electric choke.

My Roush came with the same carb, and after futzing with it for a year, I called ProSystems and had them make a double pumper for me. All hesitation and stumbling problems disappeared immediately, and throttle response was vastly improved.

Just keep that in mind, these light cars do not like vacuum secondary carbs very much. And, you are right, it is a momentary lean condition that is causing the stumble. There are only a couple of adjustments you can make to the secondaries, raising the float level, opening sooner and faster or trying a larger secondary jet. You can try a weaker spring, larger main jet or more agressive secondary cam. But, ultimately, you will probably end up selling it and adding a mechanical secondary carb. Not sure why Roush supplies these carbs, but they all seem to have driveability problems right out of the box.

Have fun.

[bret a ewing]

Originally Posted by jhv48

I believe you have a Holley Street AVenger carb. Thus, vacuum secondaries, and electric choke.

My Roush came with the same carb, and after futzing with it for a year, I called ProSystems and had them make a double pumper for me. All hesitation and stumbling problems disappeared immediately, and throttle response was vastly improved.

Just keep that in mind, these light cars do not like vacuum secondary carbs very much. And, you are right, it is a momentary lean condition that is causing the stumble. There are only a couple of adjustments you can make to the secondaries, raising the float level, opening sooner and faster or trying a larger secondary jet. You can try a weaker spring, larger main jet or more agressive secondary cam. But, ultimately, you will probably end up selling it and adding a mechanical secondary carb. Not sure why Roush supplies these carbs, but they all seem to have driveability problems right out of the box.

Have fun.

Yep..........

[D111]

Originally Posted by jhv48

it for a year, I called ProSystems and had them make a double pumper for me. All hesitation and stumbling problems disappeared immediately, and throttle response was vastly improved.

Have fun.

Jim
they look like a serious carburetor, may I ask what you paid for yours?

thanks
Dennis

[DAVID GAGNARD]

I've tried to tune a number of Street Avenger carbs,all vac. sec. carbs with the same problem as yours on a number of vehicles including heavy 4x4's to lightweight cars..doing on the little "tricks" helped,but never completely got them right.....
I'd suggest a 650 Holley double pumper for your engine combo, you will not be disappointed.........

For some reason, the vac. sec. Street Avenger carbs I've seen never did run right no matter how much tuning was done on them...
Just my 2 cents on the subject....

David

[jhv48]

Originally Posted by D111

Jim
they look like a serious carburetor, may I ask what you paid for yours?

thanks
Dennis

Dennis,
I think I paid around $670 for the ProSystems carb. My car is purely a street
Car. I went from the 770 street avenger to an 850 ProSystems HP double pumper. What a difference! Instant throttle response! No crapping out on hard cornering! No stumble on throttle tip in! And, my mileage hasn't changed. It's still crappy, but I didn't buy this car for the fuel economy. Patrick at ProSystems knows his stuff. But first, call Roush and see if your carb is on the recall list. Who knows? It's worth a shot before spending any more $$ on your carb.