newbie: 67 mustang, 289, timing/fuel issues

Intake, Newbie, hesitation, just installed. Those all together in a post tell me one thing. Check your intake . Not sealing right is likely. The other that could be causing it is your fuel psi. Check to make sure it isn't too high. ALSO, check down the carb when it is running to see if fuel is pouring down the motor. Sometimes new carb get packing material stuck in the needle and seat. Tap the back left and right corner of the edelbog to see if you can dislodge it.

Certainly check the seating of the manifold and carb as has been suggested - you may not be "running" rich - you may just have a carb riser cavity with fuel in it or intake related vacuum issues. That can cause that bog you're feeling when you goose it a bit from idle. Your timing may also be a bit too advanced - even 2 or 3 degrees off and it can feel like the engine dives under water for a second and the re-surfaces with power (does that make sense?) when you hit the throttle.

Also keep in mind that the 289 likes pretty much 2 kinds of cams - really mellow or really aggressive - something in the middle tends to give pretty nasty idle performance and un-even power through it's range.

Do Edelbrocks use a power valve like Holley's?

I've seen them give too big of a squirt and cause an initial bog like that. But I'm thinking a vacuum problem too.

10secgoal said:

edelbog .

Click to expand...

Thats funny 10secgoal. You must be runnin a Hoggy 750 double stumbler.

I agree, Check intake seal. Also you need to check for vacuum leaks from your vacuum ports. Check the base of the carb also for leaks and CRACKS. I dont know how many times ive seen the ear of a carb cracked because somebody tightened it too much. You can do a quick test for leaks by spraying carb cleaner around the intake at the heads aqnd around the base of the carb while the car is idleing and listen for a change of rpm. Other possibilities are valve adjustment (last resort), accelerator pump misadjusted (edelbrock is usually good right out of the box though), Double check firing order (you should here a little popping through carb or exhaust if this is the case). SLIM possibility is timing marks missaligned (off one tooth) during cam installation. One last thing- dont assume because you have a strong smell of gas that its a fuel problem. The amount of fuel you get is in relation to the amount of air sucked through the venturies. A vacuum leak will throw that ratio off so thats where I would check first then work towards fuel probs. Good luck.