

| Subject: | Re: Vacuum gauge readings |
| From: | Max Wellhouse |
| Date: | Mon, 27 Oct 2014 05:09:06 -0500 |
On 10/27/2014 3:22 AM, Michael Magnani wrote: > Hey Scott and Dennis, > Thanks for the feedback. Since the induction system is so short, I'm curious where would be a better place to tap for vacuum? > Mike M > > Sent from my iPad > >> On Oct 27, 2014, at 0:28, "SDF ( aka ;jim lahey' - Scott )" <scottdaniel@TURBOVANS.COM> wrote: >> >> two thoughts .. >> I'm not sure that's the best place to access engine vacuum for your gauge .. >> also .. >> I have never not found 2.1 exhaust valves to not be slightly burnt when >> taking the heads off for head gasket etc. >> >> >>> On 10/26/2014 1:58 PM, Michael Magnani wrote: >>> Hi all, >>> I just completed an installation of a voltmeter, oil pressure, oil temperature and a vacuum gauge in my stock, 1990, 2.1 WBX with 105,000 miles. No leaks, no smoke. Everything nice and as it should be - except for the vacuum gauge. At idle, instead of reading the expected 20 In. Hg, it reads about 13. When I rev it up and then let go of the throttle, the needle will get to 20, but then go down into the 13-15 In. Hg. range. I've got the 1/8" vacuum tube Teed into the hose between the Air Plenum and the Fuel Pressure Regulator. I've tried two different vacuum gauges to verify that the dashboard gauge is reading properly. >>> I've verified the ignition timing at 35 degrees BTDC @ 3000 RPM with the temp sensors connected. The engine runs perfectly and makes as much power as it ever did. I'm confused. Can anyone offer any help? >>> Thanks, >>> Mike M >>> >>> Sent from my iPad Micheal: My VDO vacuum gauge reads in that 13-15" range at warm idle and I rarely see 20" on deacelleration. I find that the gauge helps me keep my foot off the floor when driving on the highway, especially when havingthe throttle only 3/4 of the way down shows 5-10" on the gauge and foot to the floor shows like 0" and I seem to travel the same speed regardless of foot position.....lol Something a list member advised me many years ago concerning the tubing for the long run fro mengine to dash was I was using 1/8" soft copper tubing and the list member recommended going smaller, so I bought some plastic 1/16" hose(kinda like the old plastic air shock lines) and fished it inside of othe copper tubing already in the van's undercarriage. The listmember's thinking was that the diameter of the 1/8 ine was stealiing a great deal of vacuum from the engine that cold be used for operating the power brake servo. The second benefit was that the gauge had a much faster response time with the smaller hose. YMMV DM&FS
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