General MAP sensor what does it do

[trigger7108]

I've had problems with my ECU/fuel injector light coming on. Fiddled with bits and pieces on engine and I took off the hose on the MAP sensor. Fault cleared up to now But the real question is what does the sensor do and have i goosed anything by taking it off when the engine was running

cheers Trigger

 

[arc]

map sensor tells the ECU what the manifold pressure is. it uses it in fuel calcualtions.

imagine the fuel map as a table, with RPM across the bottom and MAP up the side. Then all the boxes on the table are the fuel values.

 

[trigger7108]

Thanks for that but will any damage occur when i disconnect the air hose off the bottom of the sensor, If the light comes back on i may just put some tape over it to hide the light if i cann't see it it's not a problem

cheers trigger

 

[balidey]

How do you know the light means the MAP is faulty? If you've had the code read, then just get a new (or used sensor)

And I would not want to run the car without a MAP sensor, god knows what the fueling would be like, you could run it too lean and blow a hole through the piston. That is if it runs, IIRC mine stalled when pulling the hose off.

 

[arc]

Don't run without it. The engine needs it. Correct fueling is kinda fundamental to correct running of the engine.

 

[trigger7108]

No i am not running without it connected, i just removed the hose off the map sensor then refitted it with the engine running, the main problem is that the ECU light comes on intermittantly, but in the week since i disconnected the sensor hose then reconnected it it has (touch wood) not come back on.

Cheers Trigger

 

[rallycinq]

When the ecu light comes on the engine goes into safe mode, so you do not get optimal performance. The engine will slightly overfuel and revs will be restricted. The ecu light occasionally coming on, then going off again, is not a fault.

It can occur after prolonged fast running, when the 02 sensor sees something different, or it can be temerature or water related.

Don't just put a bit of tape over the light, get it sorted.

Cheers

D

 

[trigger7108]

The car successfully ran without any problem since i originally posted this thread then 2 days ago i went to start the car and it was difficult to start and the ECU light came on again. I disconnected then reconnected the Air Pipe to the MAP sensor and the light stayed off. This is the first time i had restarted the car within a short time. Same again yesterday i had to start it again after about an hour same thing happened again. Does this point to the MAP sensor or am i just seeing a coincidence.


Cheers Trigger