Help! Running super rich at boost!

[AlexPro]

Ok here is the problem...
So I finished rebuilding my T25 today. Started putting all back on my engine and decided to finally install my AEM wideband. So I finished the everything and was very exited to see what is my F/A mixture...
Soon as I started the car gauge was showing 14.3-15.6 not stable...
If I'll give it gas it goes to 12-14 and when I let go it's lean right away and shows --- on the gauge...
While driving in boost is 10.0 but in vac its --- again... What should I do?
I tried removing SAFC but is same...
Could it be my timing set wrong? I had head gasket changed not to long ago, about a month ago or so...

 

[1990AWD]

10:1 AFR under WOT is normal and when you let off completely, it will go all the way lean (my LC-1 shows 22:1) showing there is no fuel going into the engine. Cruising around, the car will try it's best to stay at 14.7:1.

 

[AlexPro]

Actually this in not WOT, any time when my boost over 5 psi and up im running 10!
That's at 25% Throttle...

 

[AlexPro]

Any One Else?

 

[DROPthatCLUTCH]

Blt.

 

[AlexPro]

Ok will do today!

 

[DROPthatCLUTCH]

Let me know how it goes.

 

[AlexPro]

Will do, I really hope that my only problem

 

[Djsniperwolf]

Either a boost leak or o2.. Since it is not at WOT...

If you have a lazy o2 sensor the readings will be all over the place, especially at boost when you are spraying more fuel..

 

[AlexPro]

Hi
Okay I have preformed BLT and I could not find any pipes leaking air, but I have noticed all air that was pumped in was leaking out from my valve cover breed hole even when PCV line disconnected and pluged the port on the IM??? Is that normal???

I've created little drawing to show the way I was doing BLT.
BLT.bmp (1.16 MB) - FileBucket

 

[Swish]

Im assuming you mean breather hole.
Im no DSM superman but im pretty sure thats not good. Well at least not the amount you are claiming. i think they call it blow-by but dont take my word for it.. do a little more searching on here. I remember running across a thread on here about this issue.

 

[SlickPyro]

First, nice paint skillz.

As for your wideband question that all seems perfectly normal to me. I've have had a wideband in my 1g with a 14b for a long time and on a stock ecu anytime I hit boost, no matter what throttle percentage, the a/f was 10.0. At idle it should wobble around 14-15.5. stoichiometric ratio is 14.7:1 and it will wobble around there because thats how engines and o2 sensors work. When I got my stage 3 dsm chip when I hit boost now its 11s on my wideband and not 10. Just a better tune then stock. And it still wobbles around 14.7 at idle. Also when you hit boost it goes 10 then you let off it goes --- or if you are cruising on the highway just light throttle going 65 it should be around 14.7 then if you let off it will show --- because there is very little gas going in like 1990awd mentioned.

As for your boost leak test, in your pic it shows you have the throttle blocked open. So if air is flowing into the combustion chambers and then coming out the breather valve that means somehow air is getting into the crankcase. The next step should be to do a cylinder leakdown test. You can rent leakdown testers from auto parts stores. the tester screws into the spark plug hole. position the cylinder at tdc so both valves are closed any you pressurize the cylinder. also pull the dipstick out. there is a gauge to show you if air is leaking out. performing the test on each cylinder. if one is leaking air then you have to find out where.
If you have these results this is the issue:
if you hear air coming out the intake, bad intake valve seat
if you hear air coming out the exhaust, bad exhaust valve seat
if you hear air coming out the dipstick tube, bad pistion rings
if you see bubbles in the coolant, bad headgasket or cracked block.
not saying you have a cracked block or anything, just for future reference.

Good luck with this and hope you get it figured out.

 

[moving-violatio]

Just as was stated before when you let off the car cuts the fuel and your wideband will read -- in the red until the pedal is pushed again or you put it in nuetral. Also how did you adjust the safc, im guessing that you have made little adjustments in an attempt to lean it out. When you used it, did you set the throttle position? There are 2 maps used, lo and hi. Lo is for cruising and Hi is for wot. VFAQ has wonderful right up on it, I am still playing with mine to get correct fuel ratio w/o knock.

 

[Junfan]

It sounds like your STFT and LTFT might be way off. When I make a change like this I will normally reset the ECU to unlearn anything and then hook up my laptop and get the car warm and drive it around without putting my foot in it making sure my fuel trims are getting adjusted.

 

[crash89]

10:1 a/f is normal under load on a stock ecu. If you were to tuned with link and play with your fuel maps you can lean it out to where its not so rich under load. After I tuned my car I now read somewhere around 11.2:1 at WOT.

For the other question, I think SLICKPYRO pretty much covered it all. Great info!

 

[jtmcinder]

10:1 a/f is normal under load on a stock ecu.

True, but irrelevant. Re-read the first and third posts.