Possible Map Sensor fault

[Tony C]

Hi guys thought better start a new post instead of taking over the 1.1.44 post in software,

Is there anyway i can test the map sensor to see if it has died?
as only getting about 14-16kpa while cranking,

also i have an external  Accel DFI 1 BAR map sensor here,
but not sure how you wire it up,
on the box it says 74764,
on the sensor PART 12247561

on the terminal posts it says  C B A

[Sprocket]

What is the map sensor offset and range currently? also what map sensor is fitted, built in or external?

[Tony C]

range 250
offset 12.25

its internal on the board and is what ever comes on the board with ecu,

[Seight-v8]

tony,

As far as i can see....the map sensor should read atmospheric pressure (14.5psi or 100kpa) when pipe is disconnected, otherwise gotta be a fault.

Could only get mine to read 89kpa, with the max 32kpa offset, so think mine is faulty.

But not been working on my car now for over 3 months as other priorities need srting first.

You can test it with a foot pump and good reading pressure gauge as 250kpa is about 36psi, so take 2 readings and compare the results.

Did mine and it works quite well......just my readings are also wrong.....

scott

[Tony C]

its weird how mine ran ok last weekend scott,
parked it in the garage,
came out yesterday to drive it and now this,
i knew there was a fault when it didnt fire on first crank, as she fires and runs instantly from cold and hot,
the grief this ecu has given me in repairs in the past two years would of been cheaper to buy a new one  ,

[Tony C]

i just tried the pump idea on the map sensor before i go to work,
and no reading change just fluctuates between 14.8 and 15 kpa, with or without the pump connected,
Is it confirmed dead?
i changed the off set reading to max which was 37.5 (or there abouts) and it went up to 37.8 kpa

[Seight-v8]

tony,

it's gotta be fubbard....you could check the connections inside the ecu...

make sure all the connections are sound and are hot glued in place....

Sure the info says they are 0.5% accurate.

Mine reads 89kpa with engine not running and 32kpa offset.

Dont' know the wiring side....best speak to dnb for more info

scott

[Tony C]

yeah i have checked inside mate,
i found the pipe conection inside the ecu was undone, the locking collar that holds the pipe from the map to the pipe nipple on the case was half way down the pipe, retightened this up but made no difference,

mine usually sits at 99-100kpa with engine not running,
and 45-50 kpa with engine running,

Have sent Dave an email, asking if he would take a look to see whats wrong,
as he sorted the ignition prob out last October when it refused to start when we upgraded to wasted spark,

[GintsK]

Frozen condensate? It could be easily to damage MAP sensor this way. It is wise to orient sensor inlet downwards.

Gints

[dnb]

Tony - it does look like you MAP is fubared.  My guess is that it's not powering up properly - this could be a number of things.  I can't understand why you seem to have all the bad luck with that car

What are timings looking like with the engine work etc?  I'll try to line things up with that.

Seight - you can most likely make yours right by changing the "MAP sensor range" parameter.  

[Tony C]

hi Dave,
Looking like next weekend is my next spare slot at the workshop,
Has any one a spare ecu i can borrow till mines repaired?
As would like to drive the car to workshop, and run engine up after refit to make sure everything is ok before leaving the workshop in case theres any probs due to strip down and rebuild,

[dnb]

I have a spare ECU, but I think it only has 6 working inj channels.  (will test and let you know)  I doubt I can get anything done before next weekend.

As a temporary measure, assuming it is just a dead MAP sensor in your ECU how about you switch the ECU into AlphaN mode?  This should allow you to drive the car to and from the workshop.

[Tony C]

if you do have a spare ecu that would be very handy mate,
the car is due at a show easter monday and a race meeting in 3 weeks time,
so as long as i had a working ecu by then i dont mind waiting,

what needs doing to run alphaN mode?
as can try that if your ecu is only 6 inj channels,
Caprisport have offered to collect the car on a trailor this coming weekend, but we are back to sqaure one then we cant run the engine up to make sure every thing is fine before we leave the work shop.

[Tony C]

if i have to start changing a lot of settings just to try and get her to run, would rather leave it and get the ecu repaired as i know it starts and runs on the button with current settings mate,
The ecu is boxed up and ready to be sent off if need be,

[Tony C]

Right i hope the map sensor is dead now as just ordered one today from the vems shop.
ordered a 250kpa one same as whats on the board, (i hope)..
will this be ok up to 8psi of boost??
as got a paxton supercharger to fit middle/end of this year.
Any thing i need to know if i attempt to change the map sensor myself?
and will it need setting up???