VN series 1 MAP sensor problem

[Bookanun]

Hi all,

I have looked through as many posts as i can and I ant find much on the MAP sensor. Apologies if this has been asked heaps. I did the fault test on my VN last night and it came up with error code 33.


The fuel pump, fuel filter and water pump have just been replaced by myself, so it starts fine now, but has a bad miss at idle. I suspected the injetors needed a clean, but I would like to get this MAP sensor sorted out first.

Firstly, where is the MAP sensor? Does this commonly fail? Is there anyhting else that could have caused this?

Thanks for your help.

[stocky]

map sensor is the little black rectangle plastic box that is mounted on the firewall on the passenger size

[Bookanun]

Thanx stocky, I have just finished looking at it and the vauum line is fine, would the map sensor make it run poorly whilst idling? I have also replaced the leads, spark plugs, gave it a service yesterday and checked that all parts of the coil pak were working, which they are.

Any other ideas?

[vn calais manual]

try another map sensor, these dont usually mess up though to be honest..., got any **** in ur throttle body? try cleaning out ur IAC. is it just on idle or is it rough all the way through the revv range.

also try resetting your ecu by disconecting the fuse or a battery terminal for 30 seconds, and see how u go then.

[Bookanun]

Ok I have changed the MAP sensor, and it,is still missing.I have reset the battery and the code is now 12, all good.

So it obviously wasnt that. It is still running rough, where is the IAC valve? Only other thing i was thinking is injectors? Only does it at idle, sounds good through the rev range.

[thek]

So it obviously wasnt that. It is still running rough, where is the IAC valve?

the iac valve is mounted on the under/back side of the throttle body. you will need a torx bit (its a size 20 i think) to get the 2 screws out.

but be careful cause the screws are small and break pretty easily apparently.

i sprayed mine up with wd 40 and gave them a little tap with a nail punch to loosen them off.

[stocky]

to check injectors, unplug the connectors one at a time, plugging each one back in before you unplug another. the engine note should change if the injector is good. if its buggered, you wont notice much change at all

[Bookanun]

Well i did the injector test and low a nd behole, it seems definatly 1, maybe 2 arent working, so its the injectors! ordeing them soon.

Thanks to all you guys for your help, its has gotten me this far already!

Cheers fellas, luv ya work

[centy]

try to get vp injectors, i'm told they are a little better.
they were cheap on ebay a while ago $80ish a set exchange.

[Cheap6]

The 'injector' test will tell you which cylinder(s) is/are missing but not necessarily the cause. With a MAP sensor code and an engine miss at idle, perhaps a vacuum leak? Maybe an inlet manifold gasket leaking, a hose cracked/split, leaking injector to manifold 'O' ring(s) or a burnt exhaust valve.

[Bookanun]

I will try and do the injectors first, after that i will try inlet manifold and check all hoses tomorrow to make sure.

Thanks again guys, will let u know the progress!