2f Carb Tuning - Timing - and Vacuum Routing for Desmog (2 Viewers)

[NeverGiveUpYota]

Any open ports or hoses that your not sure about, spray just a little carb cleaner or starter fluid or post images here.

On any open port? Is it just me or does that seem risky for a newbie?

 

[g-man]

Ok. Maybe not on the hot exhaust manifold but you can't fix stupid.

 

[g-man]

I'm guessing he has some metal lines and hoses that aren't hooked to anything...so spraying starter fluid in them is no big deal. Anything that is a connected to vacuum is going to pull the starter fluid back to the carb/intake and rev the rpms. Get under the truck and spray up on the intake manifold where it bolts to the head. (before the engine is too hot)

 

[NeverGiveUpYota]

Carb fluid is the better choice from what I know.

 

[Seth S]

On any open port? Is it just me or does that seem risky for a newbie?

propane is a little safer...though sometimes the fan can blow it too much. I believe I still have a wand kit that attaches to a propane bottle and allows you to deliver propane to your desired area...low volume.

 

[Infinity00]

One thing not mentioned so far is whether your brake booster could have a vacuum leak. Easy to check. Remove the line and plug it so the brake booster is removed from the vacuum system.

You can also put your vacuum gauge on the remaining open ports to see if they have vacuum or just plug them. Good practice anyway.

The vacuum routing still being incorrect can cause some low vacuum as well. Check all of mwebs posts, I think he had systematically removed and plugged things to check if they were bad. Most of yours is already removed so plug all open ports and re-verify your routing.

Pull your carb off and look straight down to see the hairline crack (it’s hard to see sometimes) and get the cracked intake manifold repaired. We all have had to do it. This is another source of vacuum leak.

 

[dannyvp]

Ok the items I checked.
Spark on all cylinders. New wires also.
Moved vacuum Gauge to gas filter on manifold.
Brake booster removal seems to have no effect.
No open items I could find with vacuum.
Fuel Control Solenoid is Working

 

[dannyvp]

 

[NeverGiveUpYota]

Quick learner! Congrats.
I didn’t see what’s going on w/ your pcv? Did you pull the valve and clean it w/ brake clean and shake it to make sure it’s not filled w/ crud?
Definitely marbles from the tailpipe. Have you read through G’s description of doing a valve adjustment? Maybe that’s the next step. I saw the idle down in the 600’s, so your really doing great other than the exhaust noise and slightly low vacuum. I’m not familiar w/ your area, what if any elevation are you at? Are you running a cat?

 

[dannyvp]

I didn’t see what’s going on w/ your pcv? Did you pull the valve and clean it w/ brake clean and shake it to make sure it’s not filled w/ crud?

I have not.

Definitely marbles from the tailpipe. Have you read through G’s description of doing a valve adjustment? Maybe that’s the next step.

No but i'll look it up now.

I’m not familiar w/ your area, what if any elevation are you at? Are you running a cat?

I'm at 300 ft elevation. But my goal is a truck to make it to the mountains on the east coast.

I don't think I have done much, I may have fixed a few small issues, but I still have the same problem.

 

[NeverGiveUpYota]

I have not.



No but i'll look it up now.



I'm at 300 ft elevation. But my goal is a truck to make it to the mountains on the east coast.

I don't think I have done much, I may have fixed a few small issues, but I still have the same problem.

Black smoke? Have you driven it after all your tweaking? Are you sure the vacuum advance pot on your diz it working? You’d need a mityvac ($20 on Amazon) to check the ports to see if the diaphragms are holding vacuum.

 

[dannyvp]

Black smoke? Have you driven it after all your tweaking? Are you sure the vacuum advance pot on your diz it working? You’d need a mityvac ($20 on Amazon) to check the ports to see if the diaphragms are holding vacuum.

I think it whiteish smoke now. I've been sitting beside it tweaking so much my eyes are burning.

I do not know about the vac advance port. I think I saw somewhere a post on how to test it.

Trying to find the valve adjustment post now.

 

[NeverGiveUpYota]

Lots of decent YouTube videos on valve adjustments too. It’s definitely a finesse of sorts. May take doing it a few times to get the feel. I’m short too so when I do it I lay a stretch of folded cardboard then a yoga (it’s now part of my tool box essentials, I hated yoga) mat to lay on to get to the rear most side of the head.

 

[Infinity00]

Is your gas filter port open? That’s a giant vacuum leak if it is...

 

[Infinity00]

Probably not....but it was hard to tell in the video

 

[dannyvp]

Is your gas filter port open? That’s a giant vacuum leak if it is...

View attachment 2040856

its a screw stuck in it.

 

[NeverGiveUpYota]

its a screw stuck in it.

You can replace those w/ a one port connection. Someone posted a thread w/ them. I’d replace it if I was you, they are known to develop leaks around the 5 point part, whatever that’s called. And clearly it does since it’s laden w/ some sort of hardened sealer.

 

[dannyvp]

Valve job done, cleaned and regapped the plugs.
Seems to be running pretty good. Still has some smoke. Especially under power.
You can also still smell the fuel.

 

[g-man]

Now that you have done the valve adjustment, you should go back and try to adjust the timing again.

Not sure but I wonder if you are off a tooth on the dizzy. Did anyone pull it out? It should advance more than a 1/4 inch.

How far off were the gaps in the valves?

 

[dannyvp]

Now that you have done the valve adjustment, you should go back and try to adjust the timing again.

Not sure but I wonder if you are off a tooth on the dizzy. Did anyone pull it out? It should advance more than a 1/4 inch.

How far off were the gaps in the valves?

Set the timing back to 16deg?

The dizzy has not been removed. It may have moved more than that. But it wasn’t much.

The valves were close. Maybe a little “loose”.