Intake manifold vac lacking

[heygibb]

Hi folks. I'm attempting to induce some Seafoam into the manifold via the vacuum line located near it. I've done this in other vehicles and been successful. I am finding that there isn't enough vacuum on that port to do the job. I let the car warm up and still no discernable vacuum. What would be the cause of low vacuum there? Can I spray carb cleaner in that port to clean it out? I will add the Seafoam to the gas tank anyway, but wanted to apply it more directly to the manifold. Is there anything I can do to correct this?

Thanks

[padgett]

I use the capped brake line on the plastic octopus. (top of manifold, behind throttle body).

[heygibb]

Thanks. I'll try that tomorrow.

[Ronnie]

Be careful about sucking in too much at a time.

As stated on Reattaowner.com:<div style="border-top: 1px solid #ff0000; border-bottom: 1px solid #ff0000; padding: 10px; background: #ececec;">Dumping Seafoam into the engine too fast could result in engine damage due to the pistons trying to compress the liquid!</div>

[heygibb]

Be careful about sucking in too much at a time.

As stated on Reattaowner.com:Dumping Seafoam into the engine too fast could result in engine damage due to the pistons trying to compress the liquid!

Right. I usually take it slow, letting it almost stall the engine but not quite. Good advice.

[heygibb]

I use the capped brake line on the plastic octopus. (top of manifold, behind throttle body).

I just uncapped that line and it kills the engine w/ the cap off. The vacuum is very strong there and will easily suck up the Seafoam, but I'm trying to figure out how to keep the engine running w/out overloading w/ Seafoam. How do you keep the engine running when using that line? Do I squeeze the hose off w/ pliers while immersed in the can? In the past, I was able to just lift it out of the fluid as it sucked it's way down the can. I'm afraid that will kill the engine, having it sucking air.

[Guest G Froelich]

You have three other ports to choose from on that vacuum hub on top of the adapter plate, all of which would have equal pressure, unless plugged up somehow. Have you tried the one that goes to the fuel pressure regulator or the other to the transmission modulator?

[Guest ReattaFan1]

Might be a dirty throttle body, or intake manifold vacuum leak

[heygibb]

You have three other ports to choose from on that vacuum hub on top of the adapter plate, all of which would have equal pressure, unless plugged up somehow. Have you tried the one that goes to the fuel pressure regulator or the other to the transmission modulator?

Thanks for that option. I ended up going w/ the capped intake. I used a 3/8" vac line, long enough to reach my Seafoam can (12-18") and controlled the flow w/ a pair of vise grips. That port is a little oversized relative to the hose I used, so I wallowed out the inside of one end of the hose w/ a pointed router bit I had. It slid right over the port easily, yet snugly. The other end went into the Seafoam and was actually a snug, air tight fit in the currently designed bottle.