Okay, so the other day I went on some downhill runs with my friend. Car performed great other then the fact that my brakes were smoking when I stopped for a break On the way home everything seemed normal. Next day my car starts running way rich. Pulled a code 0706 a couple times, which indicates a problem with the fuel system, front o2 or exhaust leak.

Mods that might effect things. Intake, header, high flow cat and cat back, SAFC2, AEM UEGO wideband, EGR block off, timing advanced about 4-5 degrees.

What I've done so far: Found that my front o2 was loose and tightened it back down. Listened to my injectors with the car idling with a stethoscope, they all clicked perfectly. Checked in the engine bay and under the car for exaust leak, couldn't find anything. Replaced my spark plugs with bosch iridium, car runs a little smoother but still rich. Checked my timing, it was at about 15 TDC and I put it back to about 22 tdc, still running rich. I want to check out my MAF but my chilton says to backprobe the maf while it's plugged in... indicating that I slip of the rubber around the connector to stick in the probe wire while it's still plugged in. Problem is my car has a solid plastic plug so I cannot do this. I could strip the wire and test it then but I would rather not mangle my wiring. I've heard running direct power/ground to your MAF can be a good things anyway.

Thoughts? Suggestions?

 

I've been running in the 10:1 to 12:1 area instead of the 13:1-15:1 I had tuned it to before. I smell some gas when I lay on the throttle :-/

 

Anybody? I'm kinda stumped, I guess I can try my old front o2 sensor... it wasn't throwing a code when I replaced it, just old. Or maybe ground the MAF... I also have a walbro 255 fuel pump. I don't know if that could be not getting enough power or something although I don't see why it would start acting up all of a sudden.

 

get some maf cleaner in the areosol can and spray your maf element, i did this on my rb and it mad night and day between the way it ran before and after the cleaning

 

pull out the injectors, could have a ripped/leaky seal. it's occured on my car several times.

 

Some people at autozone had heard of people using throttle body cleaner to clean the MAF, but weren't sure. It didn't have anything related listed on the can. What did you use to clean your maf?

 

I'll check those out. I would think that would make more sense if it was running lean... but still a good thing to check.

 

http://www.crcindustries.com/hd/cont....aspx?PN=05110

 

Cool, know where to buy some of this stuff?

 

napa should have it, not sure about the usual pepboys/advance/autozone

 

Vacuum leak can cause you to run rich and a slight slump in idle. That can also cause an O2 reading to read faulty. Pressurize the intake system so you can listen for air leaksin the system. If there are no leaks I would go ahead with a replacement O2 sensor.
Also make sure that your in and out settings on the SAFC are correct for 91-94 it is 6in-6out, for 95-98 it is 5in , and 5 out. Throwing off the in and out can cause you to run rich.
Once you get your rich issue fixed run your timing up to 32BTDC or higher and tune it on the wide band to a 12.7:1 ratio. It gives the KA a kick in the pants. Your using iridiums so I wouldn't worry about detonation.
BTW moved to the NA section, sr guys don't give a sh*t to respond in the general forum.

 

Thanx for the advice Vinnie... I thought ideal AF for NA was 14.7:1? I remember the thread where you posted about advancing your timing with irridiums.... how can you tell what the timing is at 32BTDC the markings don't go that high... just guess based on the previous markings?

 

Digital timing light will indicate how high your timing goes. I believe on the pulley timing stops indicating at 25BTDC?
Ideal AFR's are between 12.7:1-13.7:1. 14.7:1 is stoich which is to lean of a ratio, but it can make power on a KADE with timing set between 18~20degrees. You can run advancement on stoich on a SOHC KA because compression ratio is lower about 21BTDC, but you have to use 91 octane or better and would be limited to using cheaper alternative octane fuels.14.7:1= 14.7 LB's of air to 1 Lb of fuel.

Your typical KA24de in higher RPMS will run up to a 13.6:1 A/F ratio with almost all bolt on's.

 

OK, so I'll tune to around 12.7-13.7 once I get it evened out. Should I shoot for a consistent AFR throughout the whole band or more/less on the low/high end?
I must say, even with things kinda off it pulls very smoothly with the iridiums.

 

As you get into higher RPM's you want to add more fuel. Since you are running a stock ecu and advancing the timing leans out the ratio, you can more than likely start by adding (+3) across the entire RPM range (for safety) then just tune according keep the ratio's more consistent in lower RPM's below 3000RPM at around 13.2:1 ratio, once you start getting into higher RPM's start to work the ratio down to 12.7:1 by the time you get to redline. This should prevent your engine from detonation. You should have it tuned on the dyno for accuracy, and most dyno shops have digital timing lights for advancements.