chevman

I have just swapped in a 3.4 and getting a code 34 MAP/MAF voltage but the MAF sensor is known to be good.

Now I see the 3 wire connector to the MAP sensor but not connected to anything. Where is the MAP sensor on a '85 2.8. I thought it was somewhere on the driver-side on a bracket but maybe I am looking in the wrong place. There really is no room to mount it near the coil. Does the vacuuum hose belong to the tower behind the plenum near the brake booster tee? I can get a MAP sensor and hook it on but does it come with everything to mount it?

Any help would be graciously appreciated,

CHEVMAN.

Trickster

Are you looking for the MAF Sensor or the MAF relay? BTW, there is no MAP sensor on the '85 2.8L. If you are looking for the MAF relay, it is located on the right hand side of the radiator support bracket.

chevman

I've heard different things about whether there is a MAP sensor or not. Where does this 3-connector plug go?

What does the relay look like? Do the MAF cables go there from the sensor?

CHEVMAN

chevman

Ok, I saw the relay.

But the thing that bothers me are these group of cables coming from the driver side of the water neck on the front of the engine with a 3-prong oval plastic connector pretty flat looking on the other end, whose leads are about a foot long and can only reach to about the top of the front of the throttle body by the a/c compressor bracket. In that bracket there is a square shape hole 1 1/2 inch by an inch, that seems to be there perfectly aligned with the the connector if I pull the cable to that spot.

Trickster

Do you have pictures of these connectors you are talking about?

chevman

No, I don't have any pics, but they look like the same connector just like the 4 prong on the passenger side, behind the coil. There is also a similar connector to the passenger side of the throttle body but that one has a yellow plastic flashing material on it, like a damper.

BTW, this is a 3.4 engine but it has the 2.8's timing chain cover. And I'm not sure if this could be a hold-over from that engine, like the cam or crank sensor.

TomP

Did you take any reference pictures before the swap? If you did, get 'em developed; that should help you figure out where the wires go.

chevman

These wires might be the cables from a crank sensor from the 3.8 block. The wires come out of the front of the shortblock.

The MAP sensor may be a sensor for carbureted models according to ALLDATA.

chevman

3.4 engine, not 3.8 I'm sorry.

chevman

According to KARL's boogie swap that wiring is:

Wires by 3.4 timing chain cover, leave ALONE!
I just make mine tidy & tuck under something.
It will NOT LEAK IF YA DO NOT DISTURB IT.
Mine has not over 10,000 miles.
This is some sensor on the 3.4 cam for the 3.4 computer.

I bought a new relay.