Secondary air injection problems

[Beaker™]

This may be of some use.... (orininal link HERE)

There are two systems that I’ve always disliked in our engine bays, and that’s the N249 vac booster system and the secondary air injection (SAI). I like to make it easy to work on the car, and with these on, it’s harder to do certain things. Having them removed is less clutter. The N249 is connected to your intake manifold and runs vac/boost for numerous things…such as the DV and the combi valve for the SAI. The whole system is located right infront of your intake manifold on a black bracket. Just cut the lines running to it and unbolt it. All you do then is run all your vac lines to a boost/vac source such as the intake mani. If you have a vac mani, run what you can to that to keep things simple. The SAI is used during cold starts to heat up the cat by injecting extra air into the exhaust side of the head. The pump is located infront of the engine block near the bottom, and has two crinkled hoses connected to it. One goes to your stock airbox, and the other to the combi valve, which is what directs air into the head. When removing this system, the best thing to do is to unbolt your coolant line going into the driver side of the head…yea, you’ll lose some coolant doing this but trust me it’s the only way. You can then take the combi valve off by unbolting it. There is a hole there, so you need a block off plate. Integrated Engineering andTwenty Squared Tuning offer a CNC’d block off plate with an O-ring to seal it shut. Before these came out you had to make your own, but these are cleaner and better looking than what many are capable of doing themselves.

Now that you unplugged the SAI pump and the N249, you have 3 harnesses that aren’t plugged into anything. You can either leave em be and be stuck with CELs, or you can buy 330ohm resistors (they’re cheap) and wire them in. They aren’t directional, just attach one end to one wire and the other end to the other wire. This keeps the CELs from popping up. HOWEVER, when you remove the SAI system, the cat is no longer being heated up during cold start. One of the O2 sensors figures this out, and throws an “Improper Flow” code. So, if you have emissions testing and/or are concerned about seeing CELs, a way to try and fix this is get into LW and adjust your startup/warmup fuel enrichment levels. If you lower them, you are leaning out the motor on startup and warmup. Leaner means hotter, and thus you can heat up the cat this way. Start by lowering both values to about 90%, and drive until a CEL for Improper Flow comes back on. Adjust in 10% increments each time. Eventually, you will either have the cat heated up enough to not throw the code, or you won’t be able to start the car easily. When the latter happens, just raise your startup enrichment by 5%, and lower your warmup. This way, you can still get the car started, but you’ll also be running it hotter to get the cat warm. Remember, nothing here is irreversible, so if you think you are messing something up, just put the values back and deal with the CEL.

 

[David_smith_909]

in the second paragraph of that post, he start going on about "just go into the LW and adjust your startup/warmup fuel enrichment levels" what on earth is a LW?

 

[PhilW]

Lemmiwinks

 

[h17och]

craig...just blank it off/remove it!

just follow the pipe work to the pump take it out, remove valve and blank the bad boy off

hooch

 

[roly]

i've left the vacuum line to the valve plumbed in as wasn't to sure what effect it would have blocking it off

 

[h17och]

plumbed to what?

you still got the valve hanging in?

Hooch

 

[roly]

the valve that bolts to the side of the head is still fitted i've just blanked off where the plastic pipe from the air pump connects to it

vacuum line is still plumbed into the back of the valve

 

[h17och]

oh right!!

that cover plate i showd you is to bolt to the head!!

HoocH

 

[roly]

okay, mines only in temp stages at the mo so will get one of them and rework it as required

 

[Craig!]

Roly's done it how I was going to do it... I never looked into the fact you can take of the valve with two bolts. So now I'm just going to route out the vacuum line, remove the pump and all other daft bits.

 

[acidstrato]

bit dead now i know...but i just realised it was Big Lad not Big_Lad lol are you 2 the same person? LOL

cos Big_Lad still said 'thanks'

LOL wtf!?!

 

[Big_Lad]

bit dead now i know...but i just realised it was Big Lad not Big_Lad lol are you 2 the same person? LOL

cos Big_Lad still said 'thanks'

LOL wtf!?!

Did notice there where two of us.... Because you put the underscore i thought you meant me. thanks anyway he he

 

[acidstrato]

i'll try to help you next time even it out

 

[p34ch3y]

i keep haveing this fault code pop up alot n im gessing its to do with this

(17832) any help please

 

[p34ch3y]

bump! says something bout sec air injection leak

any idears............

 

[p34ch3y]

also could some1 take a pic of where this sec air injection is please so that i can chek mine out please

 

[gavthelad]

dunno whose engine bay this is so sorry for stealing pic.......nice bay though:

 

[acidstrato]

secondary air injection system includes the n112 valve which is to the left of the black box on top of the engine, there should be 2 or 3 vacuum hoses connected to it and an electric plug. then there is a pump next to the oil sump (underneath engine) theres a plastic hose that goes up into the engine bay and pops into the stock airbox, people often mistake this for an oil breather as most filter kits come with a breather filter for you to stick on the end of this hose
the other hose off the pump reaches up to the back of the head i think?

if your fault code was 'leak detected' i doubt you'll be able to find the leak, i get it occasionally too, and looked all over. its basically the cause of the problems for which i started this thread