N249 Bypass Done and a Problem Solved ?
I've mentioned on here a few times that the car is hesitant under certain circumstances as I've not really got to the bottom of it before. Anyway, recently it got quite a bit worse so yesterday I decided enough was enough and set out to fix it. Mostly when cold, the engine has a flat hesitant spot at about 2300rpm, normally after lifting off and dropping back below 2300rpm then gently accelerating again.
I checked all vacuum hoses - no splits, no poor connections and nothing visible to speak of. I even dismantled the plate in the front of the engine under which a number of hoses disappear beneath the inlet manifold.
I dismantled the air hoses that form the breathers etc from the rocker cover and through all the valves and junctions (again under the mani) and cleaned all the gunk out of them. Some were completely blocked and they are now all nice and clean.
Reseated all of the secondary air intake hoses and ensured they were secure.
Found that the orange dipstick tube was cracked about 3/4" from the bottom. As I was looking at how back the crack was, I finished it off - it was that brittle it just snapped off in my hand. I've not been able to get a replacement this weekend so I have plugged it for now with another piece of plastic that is a pretty tight fit and has a wider top so it can't disappear any deeper into the tube or sump.
Satisfied that all was good, reseated all of the electrical connections and checked the looms to the injectors, the coil packs and any visible connections - all looks good and nothing obvious to report there.
Went for a run, and it was no better, so decided it was time to bypass the N249.
This took all of 10 mins to do - really simple and easy. Search the forum and you should find this
guide for the AUQ N249 bypass
Work done, started the car in its instantly smoother on tickover. Took it for a short run (kids in car so had to be sensible) and I could not get it to miss a beat at all. Seems to pull smooth and cleanly and the engine is now running a lot more smoothly. Hopefully I've solved the issue and done a small mod all in the same process!!! Fingers crossed!