stumbling on accel through entire rpm range

[astrochimp]

So...here we are again 

I put in the NEW Hei ignition disty with New accel wires. the 350 still has the Edelbrock 600 4 barrel and dual plane intake which only have a couple thousand miles on them. 

It starts and idles great..but when the car warms up to operating temp..

then acceleration has little power and stumbles from 1200rpm all the way up. 

I've adjusted the timing from 10 degrees..trying all the way down to 6 degrees.

I have grounding on the front a back of the engine block now. 

The Disty power is 12 volts when you turn the key to on.

 

The plugs are probably over 5 years old BUT have little miles on them. 

I've sprayed the carb with carb cleaner and then pulled off the vacuum advance line and capped it.

 

It wasn't doing this before the ignition system swap. 

 

i don't why this has to be such a catastrophic pain in the [censored] 

 

it's either SPARK or FUEL...so it'd be nice to narrow this down.

 

THANKS!!!!!!!!!!!!!!!!!!!!!

 

 

[stangeba]

Added information of what HEI dist and what coil you are using may help.

Are you sure the plug wires are in the correct firing order?

Good luck! I'm sure someone will chime in quickly.

Bruce

[dejh22]

Do you have a vacuum gauge? Might want to adjust the carb?

[Sam (Bones)]

double check and triple check the firing order, it is SO EASY!!!! to get 5 & 7 swapped

[Leghome]

did you use the original wire for the dist? If you did it might be a resistor wire and that will not work to well with a HEI. If my memory is working properly which sometime it do and sometime it don't.

[cbolt]

Did you check your spark advance using a light to make sure it is working when hot? I had a bad ignition coil once that acted the same way. Hard to diagnose because it worked as advertised when the engine was cold. I want to say I performed a resistance check when cold and another when hot, and that's how I figured it out.

[astrochimp]

Some GREat information here..like i expected.

Here is the info on the Disty

"assault racing 

KMJ performance

Chevy V8 High Performance HEI Distributor

65,000 Volt Super Coil

For sale is a new HEI distributor for small block/big block Chevys.  Applications include 283, 305, 307, 327, 350, and 400 small blocks, and 396, 427, and 454 big blocks.  Red cap. Ready to run.

Fully CNC machined and polished housing with adjustable vacuum advance.  Each distributor has a 65,000 volt Super Coil and high performance 4 pin module to insure accurate and reliable timing to 7,500 RPM.  Has Accel style coil cover which acts as wire retention and helps dissipate heat away from the coil.  The 4340 Chrome moly gear will work with cast or billet cams.  Premium cap with brass terminals.  True spark alignment for instant throttle response."

 

I Do have a vacuum gauge and should probably check and tweak mixture screws.

Will double check firing order today. but it does fire right up and idle nicely. and cold..the car accels great.

"did you use the original wire for the dist? If you did it might be a resistor wire and that will not work to well with a HEI. " That's what KMJ said too. Well apparently i DO have that resistor wire at the disty so I'll be swapping that out

 

I don't have a digital timing light for checking timing curve.

I'll also check coil resistance when cold and hot and write down the difference.

 

THANKS  

[Mo's70MCs]

If hydraulic tappets? Did you adjust the valve lash? I've seen it done wrong and give similar symptoms. Not that it's your case, though I agree it may be firing order related.

[wallaby]

My vote goes for a timing issue. 10 degrees won't work with my motor, mine likes 12-14.

Also make sure your choke is opening all the way when warm.