I just had an Autometer VAC/Boost installed. I didn't notice anythign at the shop but when I took it hope and shut off my car then restarted it, the gauge read 0. After a minute or 2 it sprung to life reading both VAC and Boost. I was informed that the VAC was prolly tapped wrong. Anyone have any pics where their gauge is tapped?? Is this the problem??

 

my defi gauge does the same thing if that makes you feel any better. don't know what causes it though.

 

It should read 0 if it's off. The minute you start the car though it should register a reading immediately. Sounds to me as if it was improperly installed. I have the Defi BF gauge and it doesn't do what you descrived BS. Something is wrong with the hook up for both your gauges.

 

My Blitz DTT also takes a few seconds before it will read vacuum sometimes also. I bet even when it reads 0, if you spool the turbo, it will show boost.

 

That is very strange. Where did you guys "T" your boost line? You should have used the line running to the Fuel Pressure Regulator or the line that feeds from the Surge Tank to the factory pressure sensor.

 

Yea...The VAC reads 0 but the Boost reads properly. It takes the VAC a minute or 2 to register...could it be tapped in the wrong place? Anyone have a pic of where it should be tapped to receive immediate feedback when the car is started?

 

I'll take a picture for you tonight and post it tomorrow.

 

Greatly appreciated!!! In your opinion, where is the best place to tap for vacuum?

 

if you guys search you can find a more accurate answer, but this happens when you tap into the fuel pressure regulator line in the wrong spot.. apparently, its supposed to go before some solenoid, not after it. it takes a while for the solenoid to open up or something, but thats why it does that. should be easily fixed though.

 

Cool!! The sooner the better as I am taking my car back to the place that installed it tomorrow (Friday)

...and you are 3 hours behind me in time

 

it shows vacuum right away if the car is started after it has been sitting for a while. if the car has been driven for a long time and then turned off when you turn it on again it won't show vacuum for maybe 30 seconds or so. doesn't seem to have any negative affects though....?????

 

Sooo...if there aren't any pics available before I return to the people who installed my gauge, where should I tell the tech that it should be properly installed so that the VAC will register as soon as the car has been started...not 2 minutes later?

 

tap into the line going from the manifold to the BOV.

 

Hey all,

I installed my DEFI mechanical boost last night and I tapped at the FPR like the project EVO here. I get the same delay in vac reading, but it seems fine. Is there any compelling reason to change it?

On a side note, on another thread, Cladius posted that a new car should run ~340-360 mmHG in vacuum and a slightly diff number when broken in. Another poster commented that this would be 16-18 HG on an american gauge like mine.

It does read that, but I'm curious. What does this indicate exactly? Why does it change when the engine is broken in, and if it's not in that range, what does that imply.

Any input is appreciated.

Thanks,

FB

 

Does anybody know who has an Apex Safc, can you read boost pressure with it? I was reading up on it on Apex's website, and it says it can display "Intake Manifold Vacuum/Boost Pressure". If this is the case, how is it display? PSI or Bar? I will be getting one shortly, and was wondering in order to read boost pressure, if I would need to also get a boost gauge or if I could just use the safc? Thanks