[cpetrice]

brian helped me set my timing,it runs better now. But now when I take off from a start,the car sputters and hesitates,sometimes dies (yes,the car is warmed up). I have to 'feather' the gas pedal. What could this be? the timing is right on. I may have to readjust the timing,but it would be off. any suggestions?

[cpetrice]

brian helped me set my timing,it runs better now. But now when I take off from a start,the car sputters and hesitates,sometimes dies (yes,the car is warmed up). I have to 'feather' the gas pedal. What could this be? the timing is right on. I may have to readjust the timing,but it would be off. any suggestions?

[WDCreech]

Does it hesitate when you step on the gas while cruising? If so, I'd say you weren't getting any accelerater pump shot.

[ December 30, 2001: Message edited by: WDCreech ]</p>

[cpetrice]

no,it runs fine when driving.I can punch it and it responds fine. Its only when I am at a standstill and give it gas does it want to stall and sputter.

[WDCreech]

Double post. Sorry

[ December 30, 2001: Message edited by: WDCreech ]</p>

[WDCreech]

I still think that it's a carb problem, but I may be wrong. You may need to wait for some more replies.

[cpetrice]

It very well could be. When Brian tried to adjust the gas idle mixture(right side screw),he put it all the way down and the engine didn't stall like it should have. The carb is about 6 months old,but may have gotten dirty from the fuel. I may buy another carb,depends on what my finances look like.

[dammen8]

I would agree with WDCreech, the accelerator would not seem to be doing its job. The only other thing I can think of is if the throttle blades are opened up past the off idle tranfer slots. That would also cause a very bad hesitation. What type of carb are you running? How fast is the engine idleing?

Chad Dammen

[cpetrice]

The carb is an edelbrock 750,manual choke (that gives me an idea,maybe the choke is open or something)

[BAB]

Wire the choke open and see if it still causes problems.....its an easy thing to try and a good place to start.

[cpetrice]

Choke is not the problem. Brian said the carb could be dirty,I am going to buy a new carb I think. any suggestions? the 750 was a good carb,want to stick with that size,and a price range of $350 or below.

[Brian Baker]

Do not buy a new carb !!! The one you have is fine, just needs to be pulled apart, cleaned, and properly adjusted. I've never opened up an Edelbrock carb, so I know nothing about them, other than they share some parts with the Q-Jet. I can tell you this, it's dirty, or leaking internally. When adjusting the drivers side idle mixture screw, turning it all the way in had no effect on idle quality. This tells me that the idle circuit on that side of the carb is not functioning. Passenger side screw, I was able to get some adjustment out of.

Timing isn't the issue. 12 degrees initial (mechanical) plus the vacuum advance, you've got plenty of initial timing at part throttle or off idle throttle.

Carb needs to be gone through, and replace that glass tube fuel filter with one that isn't as restrictive (even a stock A/C filter would be better).

[dammen8]

I think the throttle blades are open to far. The reason the mixture screws dont do anything is because the fuel mixture is being pulled from the off idle transfer slots , not the idle mixture ports like it should. The purpose of the tranfer slots is so you dont get a bad hesistation. when you lightly start to accelerate and the pump shot hasnt squirted yet(accelerator pump) the throttle blades will sweep past the transfer slot and that will create a low pressure at that point which will cause fuel to be pulled from the slots. If the idle speed is set to high it will be pulling fuel from these slots all the time and when you drive the car it will have a bad hesitation. Its to hard to explain with writting, if you want give me a call my number is on my profile.


Chad Dammen

[cpetrice]

Thanks brian. I guess that when they say the edelbrocks are set from the get-go,they were wrong. Nothing was done to my carb,I have had it for 6 months,must have gotten a bad one or something.

[Bob Dillon]

Why buy a new carb? That "Edelbrock" is really a Carter AFB, and made by Weber now. You can get a rebuild kit very cheap, and they're a snap to rebuild.

And if you DO get a new carb, don't put a 750 on that little 350. Go with the 600 CFM, you'll be much happier.

I have the 600 on my 455 in a big car. The torque at low RPM is quite impressive for a 4600 pound car-I regularly show taillights to the Gen-X 5.0 crowd in this town.

[ December 30, 2001: Message edited by: Bob Dillon ]</p>

[cpetrice]

Yeah,I am going to take the carb off and let brian fool around with it. I was thinking of buying a cheap carb,or get a junk one just to take apart and see what makes them work. I have never seen one apart. If for some reason my carb is shot,(I think it will be fine) I will probably go with a smaller carb. what diff would a double pumper make? thats what was on the car,but it was shot.

[Brian Baker]

Dammen8, throttle blades aren't open too far. Read my posting again more closely. It was only the drivers side mixture screw that I got no response from. The passenger side screw worked, and I was able to get some adjustment out of it. The throttle blades would have to be bent on one side or the other to describe the fault for this condition you mentioned. Highly unlikely. Thanks, Bob. We'll have it apart, cleaned, rebuilt, and readjusted in a few weeks.

[RAJ7395]

I had a similiar problem with my bird and it turned out to be a problem with my mechanical advance. Might want to take a look at yours while your at it. You can set the timing dead nuts but if the mechanical advance hangs or sticks the car will sputter and launch pretty bad.
The center distributer shaft had so much sludge built up that it prevented the mechanical advance from working at all. Also I found that for my car the best spring setup was when I used one light spring and one medium spring from a rebuild kit.

A big vacuum leak (at carb base or hose) will do the same thing.

Just my thoughts.

[78 GHOST]

Easy vacuum leak check..cover the primaries with your hand about 90% and the engine SHOULD sputter and die from lack of air.

If, when you cover the primaries, the engine picks up RPMs, you have a vacuum leak.

My '78 has a thin metal "gasket" below the carb. mounting gasket. When the carb. was pulled off the last time, they slightly bent the metal and that was enough to do it. Only after you are assured of no vacuum leaks can you properly adjust the carb.

My carb. (Q-Jet) was totally gunked up and a buddy of mine showed me a trick to save a rebuild. He revved the engine to a fairly high RPM (say 3500 or so) and completely covered the primaries with his hand. This caused a massive vacuum to suck all the gunk out of the passages. It worked like a charm and the car runs excellent with those 2 changes.

Stick with your carb. and dial it in correctly, you don't need a new one. A lot of money is wasted on carb. replacement without fixing the problem.

Don't be afraid to rebuild the carb. if Brian or someone knowledgeable can help. There aren't many moving parts and there are plenty of good reference books out there.

Good luck and Happy New Year.

[ January 01, 2002: Message edited by: Low Rev's ]</p>

[cpetrice]

Thanks,I appreciate it.