Need help with vacuum leak

[secondchance]

Originally Posted by Hammer

If you pulled the hose off the driver's side of the plenum (about the middle) and the pump stopped, it's the check valve...you can still get them from the dealer. But, I replaced one under both cars and they both ahve since failed. BS.

I rigged up a little loop for outside. After market check valve from any auto parts store that has them, two rubber lines, different sizes and a reducer fitting and both are fine now. The only check valves I have seen available are different sizes in and out.

I don't know why these valves last for 18-20 years and then you replace them and they go kapoot in two months. But mine did.

Last time i pulled the plenum I replaced both check valves, confirmed vacuum pump was holding, buttoned everything up and ran the motor for a while. The next morning, dreaded vacuum pump keeps running syndrom came back. So, pulled the plenum, found check valve blowing both ways, replace, button up and same thing!
Playing with what I thought was a defective check valve, I got it to function properly again!
I realized there must have been small debris somewhere in the system. So, I went out and drove the car like a mad man for a while until engine vacuum sucked and cleared all debris. Since then I have no more vacuum issues.
I am not saying you have the same situation but just in case...

[Paul Workman]

Originally Posted by rhipsher

Just take some carburator cleaner and spray it in all the outlets. Then blow it dry. Then take some WD40...

I wuz with ya up to the "WD40" part. "WD" is some great stuff, but I can assure ya it will get gummy in time (accelerated by heat) - tries to become varnish(?), I guess. And! It attracts dust.

I've had good luck on other small metal parts using silicone spray, after a good cleaning with a degreaser to first remove the oil. But, I'm not a chemist, and perhaps one that is can make a suggestion?

Just a personal observation; I would definitely stay away from the tri or tetra-chloride type brake cleaners tho. It is great stuff, but I can tell ya that stuff will attack certain types of plastic with a vengeance - becoming a gooey mess! The carb cleaner may be fine, but again I ain't no chemist!

P.

[rhipsher]

Originally Posted by Paul Workman

I wuz with ya up to the "WD40" part. "WD" is some great stuff, but I can assure ya it will get gummy in time (accelerated by heat) - tries to become varnish(?), I guess. And! It attracts dust.

I've had good luck on other small metal parts using silicone spray, after a good cleaning with a degreaser to first remove the oil. But, I'm not a chemist, and perhaps one that is can make a suggestion?

Just a personal observation; I would definitely stay away from the tri or tetra-chloride type brake cleaners tho. It is great stuff, but I can tell ya that stuff will attack certain types of plastic with a vengeance - becoming a gooey mess! The carb cleaner may be fine, but again I ain't no chemist!

P.

I made sure when I did it that I blew most of the WD40 out with compressed air. Its been 2 1/2 years since and have had no problems.
Acrylic type plastics are what you don't want to use acetone or break clean on cuz they will melt. The check valves are made of black delrin so it's safe to use on them. I learned this lesson the hard way on time. I was machining some parts out of acrylic with tolorences of +.0005 -.0000. I filled a little tub with acetone to throw the parts in after they came off the machine and I was humming right along. Then I turned around to blow the parts off I had spent all morning making and they were gone. I thought where did my parts go? I stuck my finger down in the tub of acetone and there was a sludge down in the bottom. The parts had completely melted into a clear sludge. Lexan, black or white delrin and teflon is not affected. But fiberglass or acrylic is.

[RJC061500]

Just finished with the injector replacement and finding the vacuum leak. I also had to adjust one of the secondary throttle blades. Turned out the rubber fitting going into the secondary actuator valve could not hold vacuum and I had to replace with aftermarket ones for pep boys. Thanks to everyone who replied to my post I could not have fixed the problem with your assistance. The knowledge of the members of this forum is terrific.

[XfireZ51]

Just get rid of the secondaries.

[Z51JEFF]

See anything in here that helps?[IMG][/IMG]