Problem at high boost

Post by **drifting circles** » Fri Dec 26, 2008 7:44 am

When I'm at wot I start to backfire it almost sounds like. I have a stock setup pretty much. fmic, hks bov 3in exhaust. I do have the stock fuel pump, could that be a problem?

Post by **Ca_Silvia** » Fri Dec 26, 2008 8:50 am

Do you have you Cat in? As soon as i took out my cat on my 2.5" and my 3" the back firing increased big time.

Post by **drifting circles** » Fri Dec 26, 2008 10:22 am

I have one large down pipe connected to a greddy ti-c . I just started happening within the last couple weeks. I think it could be plugs,coilpacks or fuel pump.

Post by **ca18detgabby** » Fri Dec 26, 2008 11:05 am

backfire is usually unburnt fuel..... ignition, timing or over fueling usually a likely cause

Post by **float_6969** » Fri Dec 26, 2008 2:42 pm

Check your plugs, and grounds.

Post by **boost_boy** » Sat Dec 27, 2008 1:14 pm

drifting circles wrote:When I'm at wot I start to backfire it almost sounds like. I have a stock setup pretty much. fmic, hks bov 3in exhaust. I do have the stock fuel pump, could that be a problem?

How much boost are we talking about here? Most times when you're running too much boost and not enough fuel, it will snap, pop and crack your ring lands from detonation.

Dee

Post by **RS12Turbo** » Sun Dec 28, 2008 12:58 pm

Check your timing

Post by **IggyEGuana** » Sun Dec 28, 2008 4:27 pm

if boost is up there then plug gap too wide?

Post by **IggyEGuana** » Sun Dec 28, 2008 4:29 pm

Stock injectors?

Post by **drifting circles** » Sun Dec 28, 2008 5:01 pm

Im pretty sure its stock injectors. Dee hooked it up. Dee it's the same exact setup you sent me nothing new. It just started happening within the last couple weeks. Boost doesnt hit any higher then 13lbs. I'll have to take a look at the plugs tomorrow. When I build boost slow and don't stop stomp on the gas it doesn't do it at all.

Post by **articzap** » Sun Dec 28, 2008 6:19 pm

My guess is fuel cut if he's on stock pump.

Post by **float_6969** » Sun Dec 28, 2008 7:00 pm

Yea, why are you running 13psi on the stock CA? What are you using to increase the boost?

Post by **sjbsuperman1425** » Sun Dec 28, 2008 7:13 pm

float_6969 wrote:Yea, why are you running 13psi on the stock CA? What are you using to increase the boost?

whats wrong with 13psi? the odd number? im running 12psi on wastegate.

Post by **drifting circles** » Sun Dec 28, 2008 7:38 pm

Im not using anything. Its been like that since day 1...

Post by **boost_boy** » Mon Dec 29, 2008 3:27 am

drifting circles wrote:Im not using anything. Its been like that since day 1...

What are you using to control the boost? If it's just the hose from turbo's vacuum nipple the wastegate and you're still seeing 13psi of boost, then your wastegate's actuator arm is possibly bent or you need to get some type of boost controller in there to regulate your boost pressures. What pump are you using? Fuel cut will scare the hell out of you. Makes you feel as if you've hit a brick wall or something. If there's leaks (which I doubt), you'll have this problem as well. Make sure your timing is at 15*BTDC as well.

Dee

Post by **RS12Turbo** » Mon Dec 29, 2008 4:40 am

I'm still banking on your timing being off......mine had the same symptoms, I checked the timing, and it was around 10-12btdc. Advanced it back to 15-17btdc, and the problem went away.

Post by **drifting circles** » Mon Dec 29, 2008 4:24 pm

Yea. It's just a stock setup. I Do need to get some kind of boost controller. Im using the stock fuel pump from 1991. Im going to order a walbro tomrrow and go from there.

Post by **articzap** » Mon Dec 29, 2008 6:27 pm

Stock JDM timing is 10 deg BTDC.....

If you go Walbro you'll need an adjustable FPR, if you don't already have one.

Post by **drifting circles** » Mon Dec 29, 2008 9:05 pm

no I dont. Ill look into getting one asap

Post by **boost_boy** » Tue Dec 30, 2008 4:41 am

drifting circles wrote:no I dont. Ill look into getting one asap

Bro, W.O.T.+ No boost controller+ crappy fuel pump+ anything more than stock boost+ not knowing where your base timing is set at= A disaster waiting to happen. When I built that engine, I set the crank angle sensor in the proximity of where it is supposed to be; not spot-on. So please use the proper procedure to check and set your timing. I would hate to see you whack your engine because of simple little things.

Dee

Post by **drifting circles** » Tue Dec 30, 2008 1:22 pm

just picked up a sard fuel pressure regulator and ordered a walbro. I'm going to try and get a tune next week.

Post by **drifting circles** » Tue Dec 30, 2008 9:51 pm

So last night I turn my car off and I hear my old fuel pump making a loud buzzing sound. Pretty much means its on the way out??

Post by **Anu** » Fri Jan 02, 2009 9:53 am

articzap wrote:Stock JDM timing is 10 deg BTDC.....

If you go Walbro you'll need an adjustable FPR, if you don't already have one.

IS that nescesary? im running a walbro for almost 2 years now without any problems, was one of the first things I built in. Hardly anyone on the dutch forums uses a FPR before stage 3, without problems.

Post by **sjbsuperman1425** » Fri Jan 02, 2009 3:17 pm

Anu wrote:
IS that nescesary? im running a walbro for almost 2 years now without any problems, was one of the first things I built in. Hardly anyone on the dutch forums uses a FPR before stage 3, without problems.

only necessary if you are running rich. the Walbro tends to overrun the stock FPR.

Post by **RM12577** » Sat Jan 03, 2009 2:06 am

My CA was doing that when i got it, also was running 12 psi stock when i put the engine in which i though was odd, i put an adjustable wastegate set to 10psi and a walbro and fpr on it and it lessened considerably, now it only backfires on boost, so it went from lean popping to rich and backfiring... but either way it runs better than it did lol just needs new plugs every couple oil changes and a good rear bumper wash to get the soot off....

Problem at high boost

Problem at high boost

Re: Problem at high boost (drifting circles)

Re: Problem at high boost (Ca_Silvia)

Re: Problem at high boost (drifting circles)

Re: Problem at high boost (drifting circles)

Re: Problem at high boost (boost_boy)

Re: Problem at high boost (RS12Turbo)

Re: Problem at high boost (IggyEGuana)

Re: Problem at high boost (IggyEGuana)

Re: Problem at high boost (drifting circles)

Re: (float_6969)

Re: (float_6969)

Re: (drifting circles)

Re: (boost_boy)

Re: (RS12Turbo)

Re: (RS12Turbo)

Re: (articzap)

Re: (drifting circles)

Re: (boost_boy)

Re: (drifting circles)

Re: (articzap)

Re: (Anu)

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