5 replies to this topic

[Watso]

Hi All,

I changed the exhaust system on my MPI over the weekend and now it idles at 2k rpm and whenever you touch the accelerator the engine races up to about 5k rpm and stays there until you turn the engine off.

To give a little background, the previous system was something by Janspeed and i've replaced it with a full Maniflow system, both used an LCB. The only real difference here is the position of one of the Lamda sensors. Previously it was screwed into the Y piece connecting the 2 downpipes at the bottom of the car, now its screwed into the Y shaped downpipe. Not sure what this sensor actually does though, could anyone advise if i've done something "wrong" here?

As an aside to this, i'm also struggling to get the Y piece to seal properly (car sounds pretty awful too!).

Any pointers greatly appreciated and many thanks in advance!

Watso

Edited by Watso, 06 April 2009 - 09:32 AM.

[stardude]

air leak perhaps?

i think the test is to spray wd40 around the manifold. if the revs pick up there is a leak i think.

[Watso]

air leak perhaps?

i think the test is to spray wd40 around the manifold. if the revs pick up there is a leak i think.

Cheers for the quick response, however, I checked all of this and everything appears to be sealed properly around both the in and outlet manifolds. Could this be an air leak elsewhere perhaps? (sorry, i've no idea about the throttle body/injection system).

[redhotmini]

might be the throttle cable isnt allowing the throttle butterfly (the flappy bit inside the throttle body) to return to its closed position. also check that the lambda sensor is plugged in properly, sometimes the plug insides get corroded.

[Watso]

might be the throttle cable isnt allowing the throttle butterfly (the flappy bit inside the throttle body) to return to its closed position. also check that the lambda sensor is plugged in properly, sometimes the plug insides get corroded.

cheers mate much appreciated. Checked the throttle cable/butterfly assembly and that all appears to be in working order.

I know as much in that the Lamda is sealed properly as i completely renewed the washers and when screwing it back in used a tiny bit of sealer (stuff used on heating flues!) to make sure it was air tight, however, when you say corroded is it like to be majorly so (i.e. completely knackered looking) or less obvious?

[Watso]

Sorted - Dodgy "locating" ring on the Inlet manifold.... Doh!

Thanks for the suggestions guys. Neat trick with the WD40!