No mid-range power

[The_Dealer]

for some reason i dont have much mid range/hi end power...my throttle response is excellent but once i get to about 25mph and falls flat on its face. maybe different jets in my holley 350? doesnt seem to be running rich, and it runs good and im getting about 18.5 mpg's mixed with 30's and 3.73's(compared to my 8-10mpg with 2150/metering block). what can i do to fix it? timing is dead on 12*, disty/rotor/coil(cannister summit coil)/coil wire are all brand new. i did reuse my plugs after the duraspark and cleaned them, they were correctly gapped. i kept my stock wires with unknown miles on them(autolite wires)

so pretty much when i go 1/2 throttle from a stop, low rpms it pulls good, around 3-3500(no tach so unsure) it hits a flat spot and feels low on power

 

[The_Dealer]

No midrange power

for some reason i dont have much mid range/hi end power...my throttle response is excellent but once i get to about 25mph and falls flat on its face. maybe different jets in my holley 350? doesnt seem to be running rich, and it runs good and im getting about 18.5 mpg's mixed with 30's and 3.73's(compared to my 8-10mpg with 2150/metering block). what can i do to fix it? timing is dead on 12*, disty/rotor/coil(cannister summit coil)/coil wire are all brand new. i did reuse my plugs after the duraspark and cleaned them, they were correctly gapped. i kept my stock wires with unknown miles on them(autolite wires)

so pretty much when i go 1/2 throttle from a stop, low rpms it pulls good, around 3-3500(no tach so unsure) it hits a flat spot and feels low on power

 

[dangerranger83]

Put your timing to 10 degrees and see what that does for you.

 

[turboranger2.3]

Fuel filter ??

Dist mech. Advance seized??

DOES That holley, have a power valve in it. ??

 

[The_Dealer]

fuel filter new, holley 350, about 2 weeks old, brand new. disty is duraspark, and duraspark box is brand new

 

[Hotrodlincoln]

Where is your dizzy's vacuum hooked up?
Have you checked timing advance with a light?
Still got cats?

 

[turboranger2.3]

when the dist cap is off. and you grab the rotor will it rotate 3/8- 7/16 and it spring back its not seized
thats the mechanicl advance.

if seized or the springs broken , I will be a dog.

also there two tabs that adj spring tension, under the the pick-up plate

but that is a ping issue.

did the problem start with any new parts.

 

[The_Dealer]

cats are gone, advance is on the vacuum tee, and havent checked advance timing

 

[The_Dealer]

no just kinda gradually started

 

[snake]

Does it have a catalytic converter? If so I'd be checking that for clogging.

 

[Hotrodlincoln]

cats are gone, advance is on the vacuum tee, and havent checked advance timing

Which vacuum tee? You need ported vacuum for the duraspark dizzy. Which means is comes from above the throttle plates. If you have it hooked to the block on the back corner of the intake manifold, your timing is retarding at higher rpm rather than advancing.

I don't remember which nipple I used, but it's pretty easy to find. Just find the one that you can feel vacuum increasing as the throttle goes up.

 

[dangerranger83]

I hooked mine to the vacuum tree and Im not having any problems.

 

[kimcrwbr1]

Actually mine works best on manifold vacuum from the tree by the dizzy. How is the float level on your carb and you can play with the timing sometimes the damper pully gets worn giving you a false reading try retarding the timing a little at a time 2 degrees at a time until you get better throttle responce on the upper end. You get more power at higher speeds when the timing retards. I was looking for something to do today I am going to try and time it with a vacuum guage and see if I can get a little more power on the upper end. Will let you know either way.

 

[kimcrwbr1]

Well not alot can be done with the vacuum and the timing but I believe I got it running better. Right now I have it set at 5 dbtdc or 15 degrees with the vacuum hooked up from the tree to the dizzy. I set the idle screws for max vacuum at an idle. It idles alot smoother now as well as downshifts and upshifts more posative. The 2.8 is no power house but it climbs steady when I give it gas above 40 mph with no hesitation. I will give that a shot with the time test and see how the mpg`s are as well as cold starts.

 

[The_Dealer]

Well not alot can be done with the vacuum and the timing but I believe I got it running better. Right now I have it set at 5 dbtdc or 15 degrees with the vacuum hooked up from the tree to the dizzy. I set the idle screws for max vacuum at an idle. It idles alot smoother now as well as downshifts and upshifts more posative. The 2.8 is no power house but it climbs steady when I give it gas above 40 mph with no hesitation. I will give that a shot with the time test and see how the mpg`s are as well as cold starts.

so 5* made it run better? im at 12, and other then no mid range power it runs fine, idles great(havent even had to adjust anything on it), whats the symptoms of a wrongly set float? also it just feels like its kinda having a hard time taking off. 0-25 is fine, but between 25-55 sux, takes forever and alot of throttle (3/4 throttle). once i lock the t/c at 55 its easily goes 55-75. its just getting there that it feels down on power. dunno if its a trans prob or what. feels like the stall speed is high, kinda like its slipping but shifts fine(revs high hardly any movement. trans fluid is spot on, no leaks or anything. but im getting a tap tap tap sound from the bellhousing area at all engine speeds. when i did the rear main, flexplate seemed fine(no cracks or anything). i get some vibes until i lock the t/c. i found a 1800 stall speed converter from patc i thought about getting(stocks close to 2600?) any ideas what that issue could be with the trans noises?