Still dying when I slow to a stop

[chrismoore701]

Well this is an addition to a previous post. I am still having trouble. Brand new project. Just finished it and just turned 500 miles and I start having trouble with the motor. When I Slow to stop, it sputters and dies. I have a Chevy 350. Mild cam. Turbo 350 Trans. I have tried and checked everything fuel related. I checked all possible vaccum lines. Rebuilt the carb twice and did see anything. Changed the power valve with a smaller one. I am wondering if it could be the control module in my hei. Any thoughts? At one time I was checking it. It just died. No sputter. Just died

[geezer#99]

A few things come to mind!
1. Float level.
Where is it set at?
2. What's initial timing? Checked at what rpm? Rpm in park? Rpm in gear?

[chrismoore701]

Float levels are good. As well as the timing. My engine builder checked the timing and I think he said it was 12 degrees but could be wrong. I have a couple old distributors. Was going to swap the module out with one of those

[chrismoore701]

I opened the site hole while running and nudged the truck and it dribbled out

[geezer#99]

Front float should be good.
How's the back one?

Module's not your problem!
Your timing is likely the culprit.
You need to get your own timing light and check it.

So what's idle rpm? When in park? When in gear?

[chrismoore701]

Originally Posted by geezer#99

Front float should be good.
How's the back one?

Module's not your problem!
Your timing is likely the culprit.
You need to get your own timing light and check it.

So what's idle rpm? When in park? When in gear?

Both bowls are good. I will see if i have a light, need to find a tach and check rpms,

What should timing be set? I have a vacuum delete on my advance.

[geezer#99]

Vacuum delete???
Splain that!!

As for timing, try 14 initial. Set it at the lowest rpm possible. Below 800 rpm. Plug off vacuum to distributor vac pot while setting timing.

[Dead Parrot]

For troubleshooting, 10* is a good timing spot. Enough for a decent idle and not enough to cause ping or hard to start problems. You can add more once you find your intermittent problem. There are several forum threads on timing.

Don't overlook the possibility of a loose or bad wire or connector. Or ignition switch going bad.

[truckin 79]

To set floats on Holley carbs, kind of dangerous on running car the fuel should dribble out bottom of sight plug hole when removed while car is running. Holley makes clear plastic plugs to make it easier/safer to adjust without spilling gas everywhere. I read your previous post and do not like those clear inline filters they always seemed to let debris get in-between needle and seat. The nice thing on Holleys is they are easy to remove and clean, needle and seat that is. A easy test to perform is while car is running place hand over air horn and if car idles higher you have lean condition or if it dies then carb should be running fine. I am sure you adjusted idle mixture screws already. Also a good way to check spark is with one of those cheap 10.00 testers from a parts store, it will show you how strong spark is coming from plug wire.

[chrismoore701]

Originally Posted by geezer#99

Vacuum delete???
Splain that!!

As for timing, try 14 initial. Set it at the lowest rpm possible. Below 800 rpm. Plug off vacuum to distributor vac pot while setting timing.

I can't explain it. My builder installed it. He is all over looking at my issues, but just trying to get it fixed on my end so I can learn from it instead of handing it over to him to fix it.

[geezer#99]

I see pics in your album, but can you post some here.
Likely easy to figure out from pics!

[RodsGreen10]

From all that I have read in 2 threads his mechanic deleted the distributor vacuum advance.
Chris do you now if your carb has mechanical or vacuum secondaries?
The mechanic who installed it he needs to fix it and if he can't find someone who can. I would want to know exactly what he has done and is doing.

[RodsGreen10]

Also with the Power valve you just can't be changing it without following the proper test procedure to determine which PV is needed for your application. Just changing stuff and throwing parts at it is not the correct way to fix it.

[chrismoore701]

Originally Posted by RodsGreen10

From all that I have read in 2 threads his mechanic deleted the distributor vacuum advance.
Chris do you now if your carb has mechanical or vacuum secondaries?
The mechanic who installed it he needs to fix it and if he can't find someone who can. I would want to know exactly what he has done and is doing.

My builder is more than willing to fix the issue, I am just trying to figure it out on my own.

As for the power valve, he measured the vacuum and determined the right one and gave it to me.

I believe I have vacuum secondary's. Here are some pics

[RodsGreen10]

Ok I was just curious if you even knew what you had.

[chrismoore701]

Fired her up at lunch. Put my hands over the carb and she died.

[Dead Parrot]

The distributor in your pics sure looks like it has a vacuum advance pot.

Is your truck going to be a track only vehicle or a daily driver?

That fuel filter looks like the kind that tends to turn nice looking trucks into burned out hulks in the scrap yards.

[chrismoore701]

Originally Posted by Dead Parrot

The distributor in your pics sure looks like it has a vacuum advance pot.

Is your truck going to be a track only vehicle or a daily driver?

That fuel filter looks like the kind that tends to turn nice looking trucks into burned out hulks in the scrap yards.

It has the advance pot on there, but my builder said he installed the delete kit, will ask him again

Show truck, cruiser, not daily and not track

I think I will be removing that filter, too many negative comments. put it on there because it fit.

[chrismoore701]

I think I am going to hook up the advance. Just to see what it does

[ron350]

Chris please give that glass (fireball) filter to someone you don’t like.

Years ago I was told that a plastic or a glass inline fuel filter would void insurance in case of fire.

[chrismoore701]

Will remove tonight

[rich weyand]

Replace it with a metal can fuel filter.

Do not use the "timed spark vacuum source" for the distributor vacuum advance. It has no vacuum at idle and will not change the "dying when I slow to a stop" issue. Use the "full manifold vacuum source" for the distributor vacuum advance on a non-emissions-equipped engine.

[chrismoore701]

Originally Posted by rich weyand

Replace it with a metal can fuel filter.

Do not use the "timed spark vacuum source" for the distributor vacuum advance. It has no vacuum at idle and will not change the "dying when I slow to a stop" issue. Use the "full manifold vacuum source" for the distributor vacuum advance on a non-emissions-equipped engine.

So I adjusted the timing to about 14, and then added the vacuum advance and drove it about 5-6 miles and it ran tons better. I talked to my builder and he wants me to bring it over to fine tune it. Talking about 16-18 degrees timing, and adding some hotter plugs. I pulled one and the tang was brown but the rest of the plug was black.

Questions, quoted above I should hook the distributor to full vacuum. Here is what I have to hook up and optional locations

Vacuum lines ==> trans, heater, advance, brake booster, PCV

Where I have hooked up
Trans - full vacuum, with Tee behind carb, into the manifold
heater - not hooked up right now - need to know where to hook it up
advance - port on the bottom of the carb
brake booster - manifold with tee back of carb, hooked up with trans
PCV - back of carb, in the base
left over - port on the passenger side middle of the carb

So question, are what I have hooked up correct?
Where should I hook up the heater?

Thanks for all your help, I think I may have solved the problem, seemed like carb, but now I know

[Dead Parrot]

Here is a forum thread on timing. http://67-72chevytrucks.com/vboard/s...d.php?t=274806

I wouldn't be in a hurry to change heat range on your plugs until you get your timing dialed in. By connecting the vacuum pot, you have already put more heat into the cylinders.

If by heater, you are talking about the vacuum supply for the air handling pots, that connects to manifold vacuum.

[chrismoore701]

Yes my vacuum pot for my in cab heater, what about the other vacuum lines