MAP Sensor Vacum Line??

[johnny o]

It appears that there is suppost to be a vacum line on the MAP sensor (atleast I think it's the MAP sensor, it clips onto the front window cowl area) I am wondering where that line goes to? Intake Manifold, TB, elsewhere? I think this could be my etest problem.

[SeanMatteson]

Johnny,

No. There's a nipple that looks like it should get a vacuum line, but in fact it doesn't.

There should only be an electrical connection at the BAP sensor.

Cheers,

Sean

[Jason Wild]

Sean Is right no vac line on it just the nipple so it can pull air in.

[JustinzSC]

Ok guys my map sensor has no vac line on it but my bap sensor has a clear tube about 4 inches long but its not connected at the other end.
Where is it supposed to be connected?

[SeanMatteson]

JustinzSC,

Our cars don't have a MAP (manifold absolute pressure) sensor. They only have a BAP (barometric absolute pressure) sensor. The BAP sensor should only have an electrical connector going onto it. There is a nipple that looks like it might accept a vacuum line, but in most cases this has a vent cap snapped onto it. There shouldn't be any vacuum lines attached. Perhaps in your case, someone attached a line and left it open at the other end. This really shouldn't cause any harm, but it might be unnecessary.

Cheers,

Sean

[JustinzSC]

Well im puzzled.
My 1990 does have a map sensor. I just had it replaced to pass the emmission test. I also have what I think is a BP sensor and it definately has a vac. nipple on it.
I pulled this pic of Fords BP sensor but mine looks a bit different.

[Jason Wild]

Both look the same to me not even sure if thats the right SC one or not But if your car has a map one some one F^(d up yes some times it will come up saying no map sensor on a code test dont ask me why!

[Greg Coleman]

Paul and I got the same code last week and my car only has a BAP sensor with no vacum line. :D

[SeanMatteson]

Justin,

I'm driving a '90 SC also, and there aint no MAP sensor. Who supposedly replaced your MAP sensor??? Did a mechanic just tell you that he/she replaced your MAP sensor? Could you be confusing the MAP sensor with your MAF sensor (Mass Air Flow sensor)?

Sean

[T1Bird]

Sean, isnt this the MAP sensor? grabbed the pic of your motor.. always thought it was the map.

http://members.tccoa.com/t1bird/555.jpg

[SeanMatteson]

Bruce,

What you've outlined is the BAP sensor. A MAP sensor would be plumbed into the intake stream to register air pressure there. Ours is just open to the atmosphere.

Best regards,

Sean

[JustinzSC]

Justin,

I'm driving a '90 SC also, and there aint no MAP sensor. Who supposedly replaced your MAP sensor??? Did a mechanic just tell you that he/she replaced your MAP sensor? Could you be confusing the MAP sensor with your MAF sensor (Mass Air Flow sensor)?

Sean

Sean
I watched my mechanic measure the voltage on my old map sensor and he said it was faulty after the car failed emmissions. It is bolted to a bracket and clips on the lip of the firewall in the engine compartment. The new one was $80 cdn and the car ran much better & passed emmissions. My problem is after driving at hiway speed 60-70 when i slow down the check engine light comes on. The codes I get are 41 & 91 (Hego sensor left and right lean). I ruled out a bad hego by replacing the right one and cleared the codes but they came back next time I drove the car. I connected a vac guage to check for leaks and it seemed ok. KOEO code 11 passed KOER code 41 & 91 Hego left & right lean
Has anyone had this problem ?

[SeanMatteson]

Sean
I watched my mechanic measure the voltage on my old map sensor and he said it was faulty after the car failed emmissions. It is bolted to a bracket and clips on the lip of the firewall in the engine compartment.

Justin,

OK, so we know the mechanic replaced something. If what he replaced is what Bruce has circled in the pic a couple posts back (which is a shot of my engine bay), then in fact he replaced a BAP sensor, not a MAP sensor.

My understanding is that cars will have either one or the other of these sensors, but not one of each.

...You had me second guessing myself yesterday, so when I was at Eastgate Ford last night taking the car in for an alignment, I asked a friend who works at the parts counter if he had a listing for a MAP sensor for a '90 SC. He said there isn't any such thing. He asked if I meant "a BAP sensor". That's why I'm still pretty confident that in this case, I'm right and your mechanic is mistaken. I'm not a mechanic, so I know you may not want to believe what I'm saying here, but believe me... There aren't many mechanics around who really know these cars, because they are pretty rare and they don't see them very often.

Respectfully,

Sean

[Greg Coleman]

I indeed came across the same thing as you Sean and must agree there is only a B.A.P. sensor on our cars and a good guy to confirm this with would be ED.

[JustinzSC]

Thanks guys
I am finding out real quick that these cars are quite unique.
Thats what sent me here looking for advise from people who know them.
I just got the car in March/04 and its kept me busy with repairs.
Heres a pic of the sensor on my car with the hose that is going nowhere.
It wasnt mounted anywhere, just hanging at the back of the intake.
I need to identify this thing.
I want to bring the car to a dealer and get the check engine light problem fixed but I know how the techs feel when they see stuff disconnected.
any help here is greatly appreciated.... :o

[SeanMatteson]

Justin,

OK. That is the EGR sensor. There should have been an electrical connection coming in from under that sensor. That tube is a special silicone hose made to withstand high temperatures. It is supposed to run from that sensor down to the EGR tube (I think?!) below the EGR valve. ...It's been a long time since I was diggin' around behind the intake plenum.

I hope this helps.

Cheers,

Sean

[JustinzSC]

Thanks Sean
That could explain the fault codes and poor mileage.
:)

[Jason Wild]

Ya just like Sean said it goes to the EGR tube there is a nipple on there about mid way or so to the top. Mine has a rubber hose since the old one was broken. Now the electrical connection is off from the wires that run around the fuel rall. One other thing to look for is that that egr tube is not broken as well I have found this befor.

[JustinzSC]

I cant find the egr valve.
Theres a plate on the back of the plenum assy. with 2 bolts where the egr looks like it would mount.

My Haynes manual shows an egr vacuum regulator solenoid but no EGR valve on the supercharged v6 engine.
now im really puzzled.

[Jason Wild]

what year is the car and auto or 5 speed?

[JustinzSC]

Jason
My car is a 1990 SC with aod trans.
Is it possible this 1990 car was built without an egr valve? :confused:
I am trying to get out to look at eggz 90 SC in Brantford that hes parting out to see if his car has one....

[JustinzSC]

Well eggz 1990 sc didnt have an egr valve.
It has the 2 bolts and a plate to cover the hole.
So im still puzzled to where this clear tube is supposed to be connected. :confused:
Sean does your 5 speed car have one.