very rich afr ok cruise.

[s3irios]

First post!

Hello fellas, as u can see this is my first post since i became a full member, and guess what, it's a "panic" topic :P.

2 Days ago i installed an AEM UEGO afr kit and from then i found some issues with the fueling.
In the beginning i had issues with the idle too, being FULL lean, fixed that by adjusting the idle properly from mixture screw. Now afr's sit at 14.2-14.8 on idle and 900 rpm. Poors like a kitty cat, at last perfect idle!

Specs are standard except a Garrett T25 and running 13-14 psi carb base.

OK, so to the problem and what i've done so far:

1) got the carb out, cleaned it thoroughly, checked all jets (except the 1st stage, stupid of me)
2) soldered and drilled a/c at 1.1 so i can get a bit more rich mixture at fot.
3) drilled second stage to 1.1 too
4) main jet is standard 1.2 checked it with drillbits.
5) theres no leak on carb or base(had put some sealant properly some months ago), quadra checked...
6) cleaned the air filter (had 8 months to do that)
7) did a "trick" about cleaning the platinum spark plugs (didn't check them though so they're probably blackened) with the partial removal of spark cables so an arch happens in between. Been told that it works.
8 ) finally fixed PERFECT idle (thanks aem uego i love you), 900 rpm with 14-15 afr readings al the time, and it sounds beautifully.

SO still have one MAJOR issue, it's SUPER rich on cruise. like 10.4 all the time, when i'm boosting it goes up a bit for a second to 11.7-12 then on full boost 10.8-11.6.As i said Main jet is standard so how is this happening? Checked for fuel pouring from the inside in carb, no leaks there.
Read that 1st stage jet (which i forgot to check) isn't on cruise but on beginning of boost, so it's not the one to blame.
Don't want to change spark plugs just yet ("b8evx" had them only 5 months) cause if it is still in the rich side when i do i will destroy the new ones too.
Checked for air leaks as much as i could, 2 possible spots, the air pipe from carb to fuel pressure regulator, and the pipe from carb base to aei unit. They are checked but not thoroughly.

Any info would be greatly appreciated as i'm loosing my patience not knowing what else to do.

[tubbyG]

Have you gave the carb a refurb recently? If not, get a kit and give it a go.
I had a similar issue, at the slightess touch of the throttle afr's went to 10. It turned out to be the diaphram/gasket within the accelerator pump mechanism :D

[Dave Reed]

Sounds like it could possibly be the adjustment on the accelerator pump. If I remember correctly you use a 5mm drill bit (find the carb artical on here) that will tell you exactly.

[s3irios]

New poster! (less than 10 posts)

i've done a full carb refurb with new seals and stuff like 10 months ago. Didn't see any split seals or anything today, i guess i could give it a go (that will be the 25th time i get the carb of hehe :sad:).
Thanks for the reply mate, still on the lookout for more ideas too!

[s3irios]

New poster! (less than 10 posts)

@ Dave Reed , first of all i found the article, i DO have one of the 4 bolts on the accelerator pump not tightening firmly but i don't see any leaks from there. On throttle movement the pump is being operated fully though.
Will double check tomorrow, thanks for your reply!

[Dave Reed]

Use this one

http://www.rtoc.org/boards/showthread.php?t=27381

Also you may be getting a boost leak from the loose or missing screw.. Why is it loose?

[s3irios]

New poster! (less than 10 posts)

Already read it mate, ty.
The bolt isn't missing, just doesn't go totally firm while it's full in. The surrounding might be threaded inside, so the bolt doesn't "lock".



(sorry for any language mistakes-typos etc)

[GT Josh]

It's a bit different, but me and my brother were at Santa pod last year. We were having problems with a carb. We had a spare, so we rejetted it for exactly the same spec. That one was perfect...

[s3irios]

New poster! (less than 10 posts)

Hmmm i hope it's not the carb itself although i can't restrict this idea for the time being. Thanks for info mate.

On a side note a quick question, is idle jet supposed to have a small ball inside? Removed for cleaning just now and i didn't find any and i'm sure i've read in a similar topic about the ball stucking?


EDIT: OK so i found this pic in another topic in here about the idle jet:
http://i6.photobucket.com/albums/y240/seger/idle.jpg (http://i6.photobucket.com/albums/y240/seger/idle.jpg)


So i miss the small middle part :

http://i246.photobucket.com/albums/gg96/s3irios/idlemissing.jpg

Is it possible this is why i get so MEGA rich on cruise only, 10.5-10.9 as i said above ?:scratch::scratch::scratch:

[Dave Reed]

By the look of that top idle jet I'd say it's from a different carb... Although could just be the pic n looking on my phone.

Your idle jet will also split in 2 also.. I can't recall mine ever having anything in the middle either, it's been a while since I looked at one tbh :)

[s3irios]

New poster! (less than 10 posts)

It fits perfectly and have no issue on idle, but this piece missing maybe makes the idle jet to spring fuel even on not idle circumstance, for example cruising.

[Dave Reed]

I doubt this will be your problem, as I said I can't recall ever seeing one in mine (scratch that, that's the other part that comes out :D lol So this could well give you issues!


Have you check the acclerator pump adjustment yet?

[s3irios]

New poster! (less than 10 posts)

didn't do the thing with the 5mm drill bit etc, cause the accelerator pump lever is working along with the throttle movement.
Another thing that came to mind is, when does the "accelerator pump delivery tube" sprays? along with the movement of the accelerator pump or just under boost? Damn question i know since it's called "accelerator pump delivery tube", but worth asking it at this point i guess.

[Dave Reed]

That's why it needs to be adjusted correctly as it may well be coming in to early causing very rich running ;)

[s3irios]

Fair point that i shouldn't let you get in bother telling me as i shoud have thought of that. Carb cleaner spray is starting to get on my brainzzzz :eek:

[s3irios]

Ok so, did a full carb refurb again today, cleaned-new gaskets and stuff, i installed a smaller main jet too, 115.
Changed idle jet, i did the trick with the 5mm drill bit and adjusted the richness on throttle movement.

Still the issue remains, afrs perfect on idle and very good on boost (i can go higher than 14 psi as i see 11 afr on full boost now) BUT, on standard cruise i see 10.3-10.8 afrs. When i push the throttle a bit more car goes to high 12s then on full boost on 11.
THe only thing remaining is the spark plugs to be changed as they must be black and dirty, plus a fellow r5 owner told me that my valve clearances can be off so in conjuction with the spark plugs they produce these rich afrs.


:rolleyes::rolleyes::rolleyes:

[GT Josh]

Ok so, did a full carb refurb again today, cleaned-new gaskets and stuff, i installed a smaller main jet too, 115.
Changed idle jet, i did the trick with the 5mm drill bit and adjusted the richness on throttle movement.

Still the issue remains, afrs perfect on idle and very good on boost (i can go higher than 14 psi as i see 11 afr on full boost now) BUT, on standard cruise i see 10.3-10.8 afrs. When i push the throttle a bit more car goes to high 12s then on full boost on 11.
THe only thing remaining is the spark plugs to be changed as they must be black and dirty, plus a fellow r5 owner told me that my valve clearances can be off so in conjuction with the spark plugs they produce these rich afrs.


:rolleyes::rolleyes::rolleyes:


You will get there in the end mate, keep going!! :agree:

[Mart]

Which size a/c jet is in situ?

[GT Josh]

Which size a/c jet is in situ?

Soldered and re drilled to 1.1

[Tony Walker]

My afrs cruising are great unless i press my accelerator past a certain point then it goes pretty rich, around the 11s like a switch exact same point of throttle and it dumps fuel in.

[GT Josh]

My afrs cruising are great unless i press my accelerator past a certain point then it goes pretty rich, around the 11s like a switch exact same point of throttle and it dumps fuel in.

Mines exactly the same mate. I find myself sometimes givin it abit to get up to speed and then going back to part throttle... But generally quite good if I drive like a granny :D 15s

[Mart]

Soldered and re drilled to 1.1

Try 1.2/1.25mm.

Also refit the idle jet 'torpedo'.

[s3irios]

I also drive like a granny and my fuel consumption is fooked up... it's so ironic consuming fuel on cruise hut on boost conserve more. makes u wanna go full boost all the freaqin time!!!
let's hope it's spark plugs and valve clearance fault....

[s3irios]

it used to be 1.25 mate with same results.I just drillled it for high boost. I post the torpedo so I have put a new idle jet which is one piece and were told it's the new style.

[Tony Walker]

ive not looked in to it but mines identical accelerate hard and the mixtures ok, then cruise very light throttle, even changing down gears to keep the mixture right lol.

[Mart]

Perhaps you're on the threshold of the first stage enrichment. Could try reducing that (jet), and/or upping the threshold point.

[Tony Walker]

Perhaps you're on the threshold of the first stage enrichment. Could try reducing that (jet), and/or upping the threshold point.

Thats what i was thinking but couldnt be bothered investigating lol

[Tony Walker]

how would i change the threshold of the 1st stage?

[s3irios]

Had service done today, oil filters, adjusted valves to 20-25 etc. Still cruise is super rich.
10.3 all the time. The previous owner told me that the previous from him (lol) owner had installed a stage 1 cam. But i don;t know for sure if that's the case.
Only thing left without thinking about the carb ( as i cleaned it thoroughly adjusted etc) is the fuel pressure regulator. Could it be faulty and provide whatever fuel it thinks, more than the "4psi above from boost" ? I know the answer, get an old psi gauge and measure it :wasntme:.

[Phoenix Autosport]

reading all this makes aftermarket injection sound simple by comparison :laugh:

[s3irios]

Well after reading this thread: http://www.rtoc.org/boards/showthread.php?t=29464
thought i had same issue, but still after the testing of 2 different enrichment circuits provided by Markey Mark (BD) (ty mate you're awsome), still no luck. Silly rich afrs at 10.3-11 at part throttle. I'm going to construct an aftermarket flame gun and then torch the sh1t out of the carb and/or engine along! :mad::eek::mad::mad::mad:

[Nottswoody]

Had service done today, oil filters, adjusted valves to 20-25 etc. Still cruise is super rich.
10.3 all the time. The previous owner told me that the previous from him (lol) owner had installed a stage 1 cam. But i don;t know for sure if that's the case.
Only thing left without thinking about the carb ( as i cleaned it thoroughly adjusted etc) is the fuel pressure regulator. Could it be faulty and provide whatever fuel it thinks, more than the "4psi above from boost" ? I know the answer, get an old psi gauge and measure it :wasntme:.


when my afrs were reading 10s it was because the plank owner before me had drilled all stages out to 1.5...

[s3irios]

when my afrs were reading 10s it was because the plank owner before me had drilled all stages out to 1.5...


hahahahh well i bet he never had lean issues :wasntme:

Nah umfortunately this isn't the case here, i've checked all stages etc, i even put a smaller main jet to check, STILL same...

Before starting for work i saw that the flange that is in enrichment cirquit where the small metal ball is located, in the spares that i got from markey is different than the one i previously had on.the difference is that the pointy edge is kinda taller in mine than on marks, maybe that's the case...

[s3irios]

THe one on photo below