S14 SR running a little rich, suggestions?

[BoBa524]

I'm new to SR, i just finished the install this monday and it seams like its running a lil rich. it is completely stock s14 sr, even sidemount. HKS bov and megan downpipe.

the car drives great, boosts upto 7psi no problem. however it does reak of unburnt fuel and it backfires quiet frequently. the car also idles at around 1,100rpm all the time.

I'm just looking for suggestions on what i should look for this weekend.

thanks,BoBa

[Red CiViC Hatch]

check ur vac lines. Is there a CEL. what ecu do u hav fuel mods.

[BoBa524]

vac lines are all good...new hoses and clamps. no mods to the engine or ecm. only mods are hks bov and megan downpipe.

[Hijacker]

Did you install new spark plugs? If so what heat rating are they?

Also, I assume you're venting your BOV. If you are, that does cause the motor to run rich everytime you close off the throttle plate.

As for the idle, have you set the idle with the TPS unplugged?

[BoBa524]

Did you install new spark plugs? If so what heat rating are they?

Also, I assume you're venting your BOV. If you are, that does cause the motor to run rich everytime you close off the throttle plate.

As for the idle, have you set the idle with the TPS unplugged?

i have not replaced my sparkplugs...bad i know. - suggest a correct set and i will buy them.

yup the bov is vented.

what do you mean set the idle with tps unplugged?

my main problem is the backfires.

[Hijacker]

The backfire is probably due to being enriched.

I suggest getting a set of NGK coppers or Iridiums. I like to use Iridium p/n BKR6IEX-11. If you've turned the boost up, you can use the 6 heat range or the 7 heat range. It really depends on your motor. My motor likes 6s better at 13 psi.

The TPS is the Throttle Position Sensor. It's a black box attached opposite the throttle pully on the throttle body. It sends a signal to the ecu that says "throttle is opened this much" If the signal is off, the ecu's fuel maps will be off. When you set the idle and timing, you need to unplug the TPS as the idle will change a bit and the timing will advance/retard on its own. Removing the TPS will result in the ECU defaulting to a base map that doesn't fine adjust the idle and timing.

Expect richness with venting. I'm 99% certain the cause is that for you. The ECU meters air as it flows at the entrance. It's already sent fuel to the cylinder for the metered air. So when you vent, that fuel is still on its way, but the air in the system just dropped so you end up with more fuel than air. It's why a lot of cars stall when they're stopping and venting.

The only way to vent atmo is a blowthrough maf setup or a map sensor.

[BoBa524]

lol thanks for the great explanation of the tps, i know what it is and does...i jst didn't know that trick.

and i'm going to order some of those NGKs now, thanks for the part number.

do you know where i can get the hks adapter for the recirc setup?

[Hijacker]

http://www.google.com/products...UTF-8

here's what i turned yp with a quick google search. I'd check with our sponsors, like heavy throttle and enjuku as well

[BoBa524]

so a quick update on this, checked the ignition timing and set it at 15 degrees(second one from left,) replaced the plugs with the iridium plugs that you suggested, and recirculated my BOV. and the car still backfires on shifts. any other suggestions?

[IanS]

so a quick update on this, checked the ignition timing and set it at 15 degrees(second one from left,) replaced the plugs with the iridium plugs that you suggested, and recirculated my BOV. and the car still backfires on shifts. any other suggestions?

I dont know how common this is, but with a high flow cat and straight exhaust I get backfires between shifts aswell. Its been about 70,000 miles I have disassembled most parts of my engine, I have yet to find any reason for it. My BOV is recirculated. I have come to believe that the cause of the random backfires is the fact that the SR20DET is set up to run slightly rich from the factory, so as to increase engine longevity.

[BoBa524]

I dont know how common this is, but with a high flow cat and straight exhaust I get backfires between shifts aswell. Its been about 70,000 miles I have disassembled most parts of my engine, I have yet to find any reason for it. My BOV is recirculated. I have come to believe that the cause of the random backfires is the fact that the SR20DET is set up to run slightly rich from the factory, so as to increase engine longevity.

so right now i have a gutted stock cat, i was debating which way i should go; high flow cat or test pipe.

any other ideas out there?

[Rosco]

A high flow cat from CATCO is also resonated and will keep your exhaust quieter, after running a gutted cat for a year or so, I am now ordering a catco cat. So I suggest you get one.

[BoBa524]

i don't really need the exhaust to be quieter, but i need to figure out the backfire situation. the guy before you said his backfires with a cat.

[codyace]

All SR's will let little backfires out once in a while...depends on how you let off the gas and waht not. I get one or two on track days, namely due to the on off on off stuff.

I've also noticed on most cars with cats, that they backfire quiet a bit. Not sure why.