[TRILOGY] Bad boost gauge, or something else?

[blackf0rk]

When I first installed my trilogy, my boost gauge would read ~20-23 hg at idle and anywhere from ~10-20hg at normal cruising around. And of course...9psi when under full load.

I just noticed yesterday that at idle the car now sits at 23(somtimes) hg, but mostly at 29hg! And when under full load only shows 2psi of boost.

The car definately doesn't seem to be slower, so I am thinking it's a bad gauge. Can anyone shed further light on this?

[MikesMerc]

Sounds like the guage is going out. If it was a vacuum leak, it would read closer to zero under vacuum as well as less PSI when under boost.

[RF Overlord]

^^^what Mike said^^^

A normally operating engine at idle should read around 21 inches of vacuum, less with a radical cam...I don't think it's even possible to generate 29 inches of vacuum...

[Tallboy]

With the engine off, does your gauge read "zero"?

[blackf0rk]

I'll take some pics or you all at different ops.

[blackf0rk]

Ok guys. I got into he car, looked at the gauge, and decided not to take pictures since it was at 10 hg (below 0 boost). This was after I let the car run for like 10 seconds. Looks like I'll be buying a new gauge soon...

[shakes_26]

I purchased an autometer boost gauge from Summit, well before my supercharger install, and had the same problem. SO I switched to the one supplied by Trilogy, its been okay.

also tried a different manuf (Stewart Warner) for a different look. And after several months same thing, I returned it for a replacement. Man Summit is the ****zat, they refunded me shipping and replaced it with a brand new SW gauge.problem, this one reads 2" vacuum right out of the box, not even connected. Its going back.

Moral is boost/vacuum gauges suck and blow

[blackf0rk]

Yea, it almost defeats the purpose of having one.

[DEFYANT]

I am finding that the AutoMeter guages are not very acurate. Almost more bling than for their intended purpose. I already installed the ones I have before I came to this opinion...

[Marauderjack]

If you don't let the AutoMeter gauges calibrate before starting the engine they give VERY WACKY readings!!

My proceedure is to turn the key to "Run" listen for the fuel pump to prime and the gauges to "zero" and then start it......If I start it without this proceedure the vac/boost gauge will do what you describe about 50% of the time!!

It take 2-3 correct starting proceedures to re-set it too......Give this a try and you may be OK??

Good Luck!!

Marauderjack

[Tallboy]

Jourdan, a couple of us in Florida have purchased a Stewart-Warner gauge that matches our set-up pretty well. I have one, and I switch back-and-forth bewteen this and the Auto-Meter. You can read about it here...

http://store.summitracing.com/partde...5&autoview=sku

[DEFYANT]

If you don't let the AutoMeter gauges calibrate before starting the engine they give VERY WACKY readings!!

My proceedure is to turn the key to "Run" listen for the fuel pump to prime and the gauges to "zero" and then start it......If I start it without this proceedure the vac/boost gauge will do what you describe about 50% of the time!!

It take 2-3 correct starting proceedures to re-set it too......Give this a try and you may be OK??

Good Luck!!

Marauderjack

Interesting, I'll give it a try.

I do the turn key and listen for the fuel pump and intercooler water pump, then start. I'll let it sit and watch the guages for the next few start cycles and report back.

Thanks.

[blackf0rk]

Yea, great suggestion. I'll try that when I'm in the car next...

[RF Overlord]

The Trilogy-supplied boost gauge is a purely mechanical gauge. Whether you turn the key to run and pause before starting (or not) won't make any difference. There's nothing electrical in the gauge other than the light bulb. If the boost gauge reads erratically, either it's defective or there's damage to the nylon feed line...(plugged, cracked, or kinked...or one of the fittings is loose)

[Lone_Star]

Blackf0rk
Sorry to hear that your boost gauge is not working as intended. If you will send me a pm with your name, address, phone number I will send you a new one, free of charge.
Scott