Just changed intake manifold..

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cazsper

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Location
Sunnyvale, CA
My Car
1968 Coupe: 393w, TKO-600, Maier Racing springs, Global West suspension, Currie 9in with forged axles, 3.50 gears, Trutrac, Baer brakes front/rear
1973 Mach-1: 351c 4V, C-6, 3.73:1 gears and a long "To Do" list..
I just changed the intake manifold (from Torker II to an air gap). Now, when it's idling, if I quickly blip the throttle, it surged then revs up. It has a lumpy cam and I'm having a difficult time figuring if the is a vacuum leak or a tuning issue.. And ideas?

 
What was your idle vacuum before and now after the swap?

 
.

disconnect and plug your distributor vacuum advance and check it and leave it plugged.

plug the pcv and see if that helps . . make sure the pcv hose is not loose on the carb.

make sure the throttle isn't sticking.

check for air leaks with flammable brake cleaner and the long nozzle by spraying gently . . check the intake at the heads also.

 
One symptom of a manifold vacuum leak (or any other major vacuum leak) is engine wanting to stall when (foot on brake) shifting into reverse or drive at idle (+/- 700 rpm).

 
cazsper,

Do you have a Vaccum Tester in your tool box? A Mustang owners best friend!

INNOVA 3620 Vacuum/Carburetor Fuel Pressure Tester

Helps to identify and diagnose system vacuum leaks and problems in the engine, and the various vacuum-operated motors and accessories

http://www.amazon.com/gp/product/B000EW0KPY/ref=s9_top_hd_bw_g263_i3?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=merchandised-search-2&pf_rd_r=114KK4EFCAFDFXKSV2KD&pf_rd_t=101&pf_rd_p=2188933862&pf_rd_i=15729801

mustang7173

 
I just changed the intake manifold (from Torker II to an air gap). Now, when it's idling, if I quickly blip the throttle, it surged then revs up. It has a lumpy cam and I'm having a difficult time figuring if the is a vacuum leak or a tuning issue.. And ideas?
Is the accelerator pump lever properly adjusted? What is the accelerator pump discharge nozzle size? Chuck

 
make sure to look for leaks around the intake sometimes they don;t sit right you could have a vaccum leak there.

 
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