My aem boost gauge reads 4 in hg vacuum with the engine off and no vacuum on the line. I know some of you guys have aem boost gauges, what do yours read with no vacuum? TIA

 

this is cory james from a friend name im to lazy to log in as me mine does that from time to time i have no idea why and its ready 4 in hg/

 

Thanks Cory. I guess I have to test the gauge now. It better be accurate for over $200 or I'll really be ____ed off. If I wanted +/- 2psi I could have bought a $50 gauge.

 

ya thanks cory as the real tadjo.

 

lol dang you steve lol

 

I spoke with AEM tech support and they told me that if the gauge is off in vacuum, it's off in boost too. So when I saw 6psi, it was really 8psi, that's flippin' great... Anyway, I got a RMA # and have to ship them the gauge and sensor so they can check them and replace the defective sensor. They told me they had a bad batch of sensors. Apparently the stainless sensors are questionable and the brass ones are okay.

Good thing I paid big bucks for a quality brand name that probably gets their stuff made in China. At least they seem to have good customer support, although they didn't even offer to send me a shipping label.

 

FYI, AEM emailed me today to let me know that they tested my gauge and found the sensor to be faulty. They're sending my gauge back with a new sensor. If you have an AEM boost gauge and it read anything but zero with the engine off, it is probably off by the same amount throughout it's scale.

 

Update: I received my gauge and a new sending unit from AEM today. Manifold vacuum now reads '0' with engine off and idle vacuum reads 20 in/hg instead of 26 in/hg with the defective SU.

If you have a AEM boost gauge that reads vacuum when there is none, you probably have the same defective SU and your boost psi will read lower than it actually is.

 

soooo, what psi are you actually running then? I know you thought you might be running 8psi, update update!

 

When I removed the boost gauge I adjusted my WG back to min boost for safety. With the old SU that WG setting resulted in 3-4psi boost. With the new SU, I'm now seeing 4-5psi so I would say I was probably running 7psi before when the gauge reported 6psi. What's a little odd is how much my vacuum readings have changed. Before I was seeing a max of 30 in/hg and now it's only 24 in/hg. I expected the boost to be off by 2psi but apparently it's closer to 1psi, which isn't a huge deal.

At least I feel better now that my $200+ boost gauge is accurate.

BTW, not to nag you but I've been troubleshooting my P0101 CEL for many weeks now. You said that you only get it with your test tune. What tune can you run and not get a 101? I'm guessing FIC tune with MAF clamped and remapped to avoid the 101 but I'd like to know for certain. TIA.