Just installed a boost gauge - some questions...

[Spooled-up]

I installed an Autometer Ultralite series 0 - 35 psi boost gauge in my '99 today. I used the 3/4" plug right behind the fuel filter. Just aft of that is some kind of sensor with a connector and a couple of wires that I had to unplug to get some more room to move. I plugged it back in when I was done. After the install, I took her out to see how much boost I was getting and I had a "check engine" light on.



Is this because of the unplugged sensor?



I got 17 psi at WOT. If I remember right, I should be getting around 20 psi stock. Should I be getting 20?



I'll post some Pics of the install when the woman gets back with the camera. I did it a little different than most. I'll be away until Mon night. Thanks.

 

[barryg41]

Only guess I have is that you might not have made a good connection. Make sure it clicks when you plug it back in. Or you might have bent one of the pins on the connector.



Take the connection apart and recheck the pins and such.

 

[chuck3]

Yes you should be getting 20 to 21, I think above 22 sets an overboost alarm. I think that might be the MAP sencior you unpluged.

 

[juicedcummins]

17lbs is about right for a stock 99. Thats right where mine was till I started to bomb.

 

[Bigsaint]

DMKelley, that's the map sensor plug and you shouldn't have set a code or check engine when you unplugged it, unless the ignition was keyed on when the plug was off. Remove the plug from the map sensor and apply a small amount of dilectric grease on each of the 3 spades, then re-connect and be sure that it 'clicks' into place. That should clear the check engine light.



I've had two check engine lights come on in my truck, both were related to the map plug and the second I wasn't able to clear by simply disconnecting the batterys. I have 3 map plug harnesses (sp?) in my truck with the ez and the TST boxes. I ended up just unplugging all 3 and then re-connecting the plugs, using the dilectric grease on all spades. Cured the problem for me.



Scott W.

 

[Spooled-up]

The light is no longer illuminated.

I parked the truck in long term parking for the two days I was on my trip. When I started it up today, the check engine light acted normally. Seems to have fixed itself.



I did have the ignition on accessory when I unplugged the MAP sensor. Have to have tunes you know.



By the way, What is a MAP sensor?



Thanks for the help guys.

 

[me4osu]

MAP Sensor

Manifold Air Pressure sensor. Tells the computer (ECM) the air pressure in the charge air plenum.