Slight Backfire/Fart at 1500 rpm exactly. Sr20det

[KaminaSan]

So guys, here is the deal. Every time after I get on the gas a little bit(not necessarily hitting boost, but let's say revving to 3500/4000, and then decelling, I get a very small(sounds like a loud fart) backfire from my exhaust.
at 1500 RPMS exactly. Only in 1st/2nd.
My thoughts were that this could be from a rich condition due to my BOV being a cheapy egay one.

Along with that, just recently, I started hearing a ticking coming from one of the injectors, that is louder than the rest. It only happens every 15/20 seconds though. I don't know if they could be related.

Here is my setup. Any thoughts appreciated:
Stock s13 Sr20det BlackTop
CX Racing FMIC/Egay BOV(Vent to Atmosphere)
3 inch turbo elbow, 3 inch DP(sort of banged in),
very clogged cat(replacing with Test pipe)
3 inch exhaust from catback.
Stock boost 7 psi according to my gauge.
Just recently switched to 255 Walbro.

Also, I don't know if it helps, but my vacuum shows -19 in/hg.
My FPR has its dedicated vacuum line.
Boost gauge/BOV are teed off eachother.

Is this fairly normal? I'm not worried about the backfire, but rather that it's a sign of something else.

It's not LOUD, just an annoying louder than usual big fart.

Normal?

[Bigsyke]

Its normal, thats the fuel cutoff.

However if the popping is very loud, then your timing is either too retarded or your running way too rich.

[NickyD0403]

Mine does the same exact thing at 1500rpm, but it's deffinately a LOUD pop. Did it on t25, and on my t28 w/ 550's and a tune. Wierd.

[KaminaSan]

Now more problems have arisen. While driving, I pushed it in 3rd to about 4500-55000 and it felt like the boost disappeared, lmost as if the tires were spinning freely. I checked the injectors and now it sounds like that tick happens more frequently. It boosts fine in first and second. Any more ideas?

[jdm213]

check the O- rings on the injectors maybe they are dumping to much fuel

[KaminaSan]

Took it to the awesome crew at pit garage.

We tried everything. New fuel pump, new maf everything.

Turned out that my plugs were GONE. Like 2 were super black, and two were kind of whitish, and they were the original plugs from Japan.

We swapped out the plugs, and one coilpack that had somehow turned white...

Runs better than ever. Hesitation gone, although I do hear loud ticks from the injectors randomly every thirty seconds or so.

[steve shadows]

hahahhahahahahhahahhaahahahaa

I'd be proud if I had this....


well not really just makes me laugh how anal you are about something so minor...wish every 240 owner was like this


Is you exhaust cursh bent at any point? does it have a muffler with any soft f caverns or any recesses? this can happen on decel

[KaminaSan]

hahahhahahahahhahahhaahahahaa

I'd be proud if I had this....


well not really just makes me laugh how anal you are about something so minor...wish every 240 owner was like this


Is you exhaust cursh bent at any point? does it have a muffler with any soft f caverns or any recesses? this can happen on decel

Well Steve, I see it this way. I want my car to be done the right way, and I want it to be RELIABLE, and completely sound before I go off and buy a boost controller, and try and run 15 psi like everyone else.

First thing I SHOULD have done after getting the engine in, was check all the plugs, and replace.


I figure, if I have a decent platform to start on, and I make sure this platform is sturdy, I can build on it.

To answer your question, yes, my downpipe is beat in from being slammed.

I'd rather be anal and safe with my baby, than carefree and not being able to drive her =)

[klits562]

My KA24e does the same thing exactly at 1500rpm but its sometimes quite loud and will continue to backfire somewhat rapidly and inconsitently untill about 1000rpm. Been doing it since i've owned the car for about a year and nothings changed or broken yet.
Also my friends KA24de(96) does the same as mine same rpms same sound.

[reflexdb]

Well, considering that your plugs are fouled, you're running too rich. You have a higher flow fuel pump and stock ECU, so the stock injector open time is letting in more fuel than calibrated for. Also, your injection amount is calculated from your MAF, but your blow-off valve is venting to atmosphere, so you are injecting way more fuel than you need to be - especially during decel.

[get_nuts]

my sr does this only when i shift regular but when i smash on the throttle and shift in high rpm it doesnt do it y is this

[EhrikETFG]

My KA24e does the same thing exactly at 1500rpm but its sometimes quite loud and will continue to backfire somewhat rapidly and inconsitently untill about 1000rpm. Been doing it since i've owned the car for about a year and nothings changed or broken yet.
Also my friends KA24de(96) does the same as mine same rpms same sound.

don't worry about hte single cam nothing is wrong with it. it's just how they are, especially with more then stock piping.