How to fix a carburetor issue.

[Doug Larsson]

I have a brand new Holley 2210 2bbl carburetor on a 400 bb. When it's cold its leaving black soot on my driveway every time I go some where when I first start it up to warm up. Any advice on what to adjust on my carburetor.

 

[bm02tj]

Bad choke pulloff or choke to tight or cross over plugged or heat riser defective

 

[Ranger16]

If it's only on a cold start, my money would be on the choke as well.

 

[oldbee]

Not familiar with ur carb but try going lean 1 indicator mark on choke housing; does it have a vacuum operated choke pulloff on it? That could be inop or mis-adjusted.

 

[Doug Larsson]

I'm not real familiar with this carb yet just started trouble shooting it. I have these documents to go by so far on adjustments.

 

[bm02tj]

next cold start remove air cleaner and have someone start car
the choke pull off should open choke a little if to rich adjust
if starts to run rich after a short time grab manifold where the choke spring is if hot adjust choke spring
if cold check heat riser or cross over

 

[AMX364]

The only real way to adjust a cold carb is with the air cleaner off. When you start the car, either open or close the choke valve and see which way the engine responses best. You really can only do this once a day for real results. Also check for bad choke pull off, which this way should help find.
edit: someone beat me

 

[oldbee]

#3 in left pic is choke pull-off, hook a longer piece of hose to it when eng. is cold. Suck on the other end of hose with your mouth & choke plate should pull open about 1/8" as in fig.9(?) in 2nd pic. Before you do that pull throttle partially back to set choke plate, should be some resistance to pushing the choke plate open. You can only do this on a thoroughly cold engine, let us know.

 

[Doug Larsson]

next cold start remove air cleaner and have someone start car
the choke pull off should open choke a little if to rich adjust
if starts to run rich after a short time grab manifold where the choke spring is if hot adjust choke spring
if cold check heat riser or cross over

How do you adjust the choke spring it's a coil ?

 

[bm02tj]

Post a pic of choke spring as there is a couple of different ones
The one you may have can be adjusted with a screw driver
Is the cross over clear and does the heat riser work

 

[Doug Larsson]

Post a pic of choke spring as there is a couple of different ones
The one you may have can be adjitusted with a screw driver
Is the cross over clear and does the heat riser work

I took a picture after adjusting the choke like it said on the paper i had for the carburetor. This is what it looked like on cold start and when it warmed up. In the first pic its in farther when cold the when warmed up it went out some.

 

[oldbee]

That pic is your choke pull-off, it moves the same hot or cold when running. Your first choke tension adjustment is down in the well in manifold. 3/8" nut if I remember that needs loosened and disc that is hooked to bi-metallic spring is rotated "slightly" lean or rich(more tension or less)

 

[bm02tj]

That sounds right
but have you checked heat riser and cross over

 

[Doug Larsson]

That sounds right
but have you checked heat riser and cross over

I don't know what those terms mean can you tell me what they are and where to look. Thank you

 

[Doug Larsson]

Here are the pics I took this to a shop that worked on old cars and asked them to adjust my new carburetor last year I'm finding out thru doing the adjustments I'm reading about they didn't do any thing to this carburetor. What's the saying if you want it done right do it your self lol yep !

 

[bm02tj]

On the pass side exhaust manifold is the heat riser that closes to force heat across the intake manifold to heat the choke spring to make it open quickly
if either one is bad the car runs rich until the engine heat opens the choke

 

[Doug Larsson]

So I did some test per the fsm one says to check ohms of the choke assembly it supposed to be between 4-6 ohms it came back good. I did the other test where you unplug both connectors to the choke control switch start up the car and let it get to normal operating temp and then put a test light to the small spade connector when it gets to temp plug in the bigger spade connector and your test light should come on if not or on for more than 5 minutes your choke control switch is bad. So right now it looks like the switch might be bad but I forgot to do a test to see if the rod from the choke assembly to the carburetor was hot or cold I'll do that tomorrow.

 

[bm02tj]

The electric part is to help with cold emissions
The heat riser should be closed when cold and open when hot
grap it and it should turn 1/4 turn and spring back when cold
then check crossover heat

 

[Doug Larsson]

The electric part is to help with cold emissions
The heat riser should be closed when cold and open when hot
grap it and it should turn 1/4 turn and spring back when cold
then check crossover heat

So after doing some research to understand what you meant by a heat riser I found out I'm not running one any more I took the stock manifolds off and put headers on. The pic below is my heat riser assembly you are talking about correct ? I'm sorry I think I've confused every one buy not saying I have after market headers on my car I'm sorry about that ☹.

 

[oldbee]

Headers makes a difference only on how fast the choke gets hot&opens up all the way, you've still got a cold start problem.