Guys,

I have an LT-1 car with no MAF.......eeek !

Just when I figured it out, I sold it and bought an LT-1 car. Well, hey !!!

The MAF disappeared.......and there is only a small 2-wire sensor in it's place.

I presume it's the MAP sensor.

So, I relocated it to the air cleaner box.....

and now the car bogs at WOT at 4,000 RPM.

Theory: that sensor really is measuring engine vaccuum, not air temperature......

So it really needs to be close to the Throttle Body, not down in the airbox where I put it.

On the MAF car I had before, it was the MAT sensor (temp)

But now it's actually a vaccuum sensor of sorts, right ?

Helllllllpppppppppppp !

BOR

Dazed and Confused - yeah, it's normal for me.

 

If it's the MAP (Manifold Air Pressure) sensor it MUST be downstream of the throttle body blades, or else it will always be reading atmospheric pressure. The computer be totally confused, as it will be trying to figure out how you got to 4,000 rpm without opening the throttle blades enough to change the vacuum pressure signal.

Actually, you are correct... the sensor is measuring the engine vacuum, or more accurately the change in vacuum. Turn that equation upside down, and it's measuring the change in pressure. Same effect, just different terms for it. The MAT sensor is the Manifold Air Temperature sensor that can hang out on either side of the TB with no bad side effects.

Move the MAP sensor back to the plenum where it belongs. The computer will thank you for it. I believe that the LT1s also had a MAT sensor as well, and if you find that you can stick that one wherever you want.

 

The MAP sensor has three wires and a vacuum hose attached. You must have moved some other sensor.

 

The sensor you moved is the IAT sensor. Intake Air Temperature. It's job is to measure the temperature of the incoming air. Moving it should not have that affect on your engine as long as it is inline with the air intake system.

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1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, BBK 52mm TB, Edelbrock TES, gutted Cat, Flowmaster, CAI w/K+N cone, AFPR, TB bypass, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Alum. Driveshaft, Hotchkis STB, '99 Camaro seats.

Coming Soon!!: Fourth gen 3.42:1 rear, Spohn LCAs and Panhard.

 

Just for your info, your MAP sensor should look like mine. The pics aren't the greatest, but the MAP is attached to the green connector in the lower left corner of the first picture (or top right of second). Your positioning will probably be different.



[This message has been edited by RCR (edited July 24, 2001).]