low vaccum at idle question
#16
Nordschleife Master
Your decel vacum is similar to what I get and have gotten for years, idle vacum is low which to me indicates you should take a look at your idle system...
#17
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Join Date: May 2005
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Thanks Adrial, I was just thinking, could the idle rpm have an effect on idle vacuum. For instance, my idle is set at about 1000 rpm. Should I lower it down, or would that make no difference?
#18
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your idle vacuum can also have a lot to do with the work, or how easily, your engine runs at idle. For instance, if you have your a/c compressor running, your vacuum will be a little lower because your engine is meeting more resistance
#19
Burning Brakes
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This may be a long shot, but -
Vac Gauge error? Possibly tiny leak in the vac line to the gauge? Sounds like the system is tight...
Sunroof. Cruise Cont. delete, tan Sport Seats - that's sweet. Welcome.
Vac Gauge error? Possibly tiny leak in the vac line to the gauge? Sounds like the system is tight...
Sunroof. Cruise Cont. delete, tan Sport Seats - that's sweet. Welcome.
#20
Hey Joe, this may be a longshot, but did you zip-tie the hoses onto all the fittings? It would be more of an issue on boost but may be something to try if you didnt tie them. Also going with what Mitch suggested, what brand gauge are you using? If its an autometer it may be off a little bit. There was a thread a while back and a lot of guys had gauges that read either slight pressure or vac when the car was not running. If you re-used any of the rubber "hook" connectors you may want to double check them.
How did you connect to the vac canister, the interior vac fittings and the gauge?
John
How did you connect to the vac canister, the interior vac fittings and the gauge?
John
#22
Burning Brakes
What impact does the compression health of the motor have on idle vacuum ? For example, if a new motor runs 150 psi compression, and a worn one runs 130 psi, would the idle vacuum on the worn one have lower idle vacuum, assuming both engines had good sealed vacuum systems?
What about if one cylinder is weak on compression and the other 3 are strong ?
What about if one cylinder is weak on compression and the other 3 are strong ?
#23
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Hey guys,
Boost gauge is a VDO. TB seals have been replaced. Idle vacuum is with a/c off. Boost gauge is hooked up off a t fitting on the KLR line. Will run a comp. test and check timing hopefully tommorow. Will update,
many thanks again, hopefully my rennlist membership status will update soon, I'm envious of the nice red under your names
Joe
Boost gauge is a VDO. TB seals have been replaced. Idle vacuum is with a/c off. Boost gauge is hooked up off a t fitting on the KLR line. Will run a comp. test and check timing hopefully tommorow. Will update,
many thanks again, hopefully my rennlist membership status will update soon, I'm envious of the nice red under your names
Joe
#24
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Hello, I recently put a boost gauge on my turbo and all I am reading is boost and no vacuum.....where do I splice in my boost gauge line in order for it to show this.
#25
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Originally Posted by motoxxxdeamon
Hello, I recently put a boost gauge on my turbo and all I am reading is boost and no vacuum.....where do I splice in my boost gauge line in order for it to show this.
Boost gauges start at 0 and go on to 25-30psi, boost/vacuum gauges start from 30Hg till 20-30psi.
This is a boost gauge:
This is a boost/vacuum gauge: