7 psi on Stock gauge/15 on Autometer?

[schwag9AWD]

The problem is my stock boost gauge is only reading 7 psi, but my Autometer is showing 15. The stock gauge builds up a little slower than the Autometer and tops out at 7.

I ran a boost leak two weeks ago and I held 19 of 20 psi (lost 1psi at the BISS screw) and the autometer gauge read 19 so I know that's not the problem.

What should I check for at the MAF, or sensor? Also, if the ECU is only reading 7 psi would this affect timing? My EGT's are pretty normal, around 1300 to 1350 city driving so it doesn't seem to be running rich/lean because of this. It does feel slower up top, but mainly because my clutch is almost shot.
Later

 

[TURFNNSURF]

Just trust your AutoMeter boost gauge... The boost/vac gauge in the console shows what the ECU "thinks the boost is" based on signal input from the MAF and throttle position sensors. In other words the ECU tanslates some sensor input and makes a best guess for you to see in the Dash.. If you set up your AutoMeter according to the VFAQ install guide or RRE's install guide, Then that will be reading the proper BOOST!!!!!

 

[Enigma_Man]

Though, because the stock boost gauge calculates the amount of boost based on airflow, if you're seeing 15 psi on the autometer, the stock boost gauge _should_ be just about pegged...

If it usually pegs, but isn't now, then your car may be reporting the amount of airflow wrong. You might have a leak after the filter, but before the turbo (check to make sure your BOV recirc. tube is still on tightly, and all the stupid little connecting hoses are still there).

-Jesse

 

[schwag9AWD]

Ya, it pegs at 7 and never goes past at anytime, I don't think it's a serious problem, but it bugs me
I've already checked all my hoses, etc. and everything is on tight. The only other thing I can think of is I think the last owner might have taken out the lower honeycomb, but I've only taken the filter off once and I didn't see any damge or anything else.
I've never heard of hacking the MAF causing this, but should I even worry about?
Later

 

[my95tsi]

First of all how do you read a stock boost gauge?? There is no accurate measurement. It's just a toy that looks cool! Second of all who cares what the stock boost gauge says if your autometer says its fine. The autometer gauge is the real gauge. The stock boost guage isn't even hooked up to a vacuum source. It reads what the stock boost should be at the rpm and speed. I took off the needle on my stock gauge b/c that thing is worthless.

 

[Enigma_Man]

Originally posted by my95tsi
First of all how do you read a stock boost gauge?? There is no accurate measurement. It's just a toy that looks cool! Second of all who cares what the stock boost gauge says if your autometer says its fine. The autometer gauge is the real gauge. The stock boost guage isn't even hooked up to a vacuum source. It reads what the stock boost should be at the rpm and speed. I took off the needle on my stock gauge b/c that thing is worthless.

Well, you're somewhat incorrect. The stock boost gauge is essentially an airflow divided by rpm meter. If it's reporting something incorrectly, it could mean that the stock MAF isn't measuring air correctly, which could cause you to run dangerously lean. It is useful in that way, not very much as a "boost gauge".

I had a huge boost leak at one point (loose IC hose), and the stock "boost" gauge was reporitng a lot of "boost" while my vacuum-source gauge was reporting only slightly over atmospheric. That meant to me that I had a leak.

It's not 100% useless.

-Jesse

 

[schwag9AWD]

If the MAF is reporting the airflow or RPM incorrectly would that cause a CEL? Are there any ways I could test it out, or anything to look for on The MAF?

 

[ericismyname]

my stock gauge is usually higher then my autometer

 

[my95tsi]

I had a huge boost leak at one point (loose IC hose), and the stock "boost" gauge was reporitng a lot of "boost" while my vacuum-source gauge was reporting only slightly over atmospheric. That meant to me that I had a leak.

It's not 100% useless.

-Jesse [/B][/QUOTE]

Well thats proves my point exactly. The stock gauge will show that you have boost even thought you don't. It HAS NO USE! You figured out your problem by looking at the autometer which showed exactly what was going on. I had a boost leak also and all i did was notice my autometer boost gauge wasn't showing the correct amount of pressure.