Car Popping/Backfiring at 5000 RPMs

[xrobbx03]

Ok so my car has been running like crap for the past week or so. It seems like everytime I get on the throttle and my car hits laround 5000 RPMs i start getting popping and backfiring and the power seems to just drop off. The car still pulls nice in low rpms but in every gear it just seems to die out at 5000 rpms.

What could be going on here to cause this. I went through and checked all my intercooler piping looking for leaks.

The only thing i really have done to the car lately was replace plug wires. I just put in some new NGK plug wires in my car along with BPR6ES plugs. Since these wires come pre numbered for each cylinder would it make a difference if i changed some of the wires so they could reach the new plug order for installing my DSMlink?


Also would low compression cause a car to do this?

 

[neoviper]

Is the check engine light on? also did you do a proper boost leak test? changing the wires wouldnt hurt anything as long as the wire goes from the plug to the correct spot on the coil pack. are there any other symtoms, like trouble with cold starts or anything?

 

[BoostedTalonTS]

Check your plug gap... Running more then stock boost? -Try closing the gap to .023 -.025 and retest. -Just out of curiosity, why did you go with a stock heat ranged plug anyways? -Most will usually go x1 heat range colder, to an NGK BPR-7ES plug to better dissipate heat that would normally be retained by the stock temp plug in a high(er) boost condition.

 

[neoviper]

an just looking at your mods I was woundering why your running BPR6 plugs those are the 2 degree colder ones an should only be used on highly moded engines with 30+ boost.

incorrect. the bpr6's are better for use with stock and extremely lightly modded cars which is what most of his car is. as you go up in number (bpr7 and so on) the plugs get colder.

to the OP your car could be sensing knock which is why im wondering if you check engine light is on

 

[BoostedTalonTS]

Could be anyone of these spark plug gap, fuel cut, an just looking at your mods I was woundering why your running BPR6 plugs those are the 2 degree colder ones an should only be used on highly moded engines with 30+ boost.

Beat me to it... BUT, the BPR6ES plugs are actually OEM temp range plugs for a turbo application... as you go HIGHER in the number, the temp ranger gets colder. -Here's NGK's code chart for identifying plugs

 

[xrobbx03]

incorrect. the bpr6's are better for use with stock and extremely lightly modded cars which is what most of his car is. as you go up in number (bpr7 and so on) the plugs get colder.

to the OP your car could be sensing knock which is why im wondering if you check engine light is on

no i dont have any check engine lights on. Should I get the next step colder plugs.

Also running stock boost.

 

[xdsmlaser93x]

i had the same problem with my car. i could cruise around no problem, but once i was hammering on it in the upper rpm range it would just break up and fall on its face, i changed my plugs and checked the gap and everything has been fine ever since.

 

[neoviper]

First i would check the plugs, make sure the gapping is correct and that theyre not fouled in any way. you dont need colder plugs, but it doesnt hurt. does the car buck under load?

 

[xrobbx03]

How do I check the gap on the double prong BPR6EKN?

As for the bucking...it doesnt buck it just more of of popping and backfiring coming from the exhaust.


I might just try and go to my local parts store and see if they have the BPR6ES single prong. I know they dont last as long but im sure its easier to check and change gap. On those what should I keep them at .30?

 

[Johnnydsmdude]

I had a customer with this same problem and it turned out that it was the coil pack

 

[Defiant]

5K is also about the usual breakup point for used-up ignition wires. How old are yours?

Go out in the dark and pop the hood, and look at the pretty sparks.

 

[xrobbx03]

I just bought the wires about a month ago if that. How do I check if the coil pack is bad?

do you think it could have anything to do with the fuel filter? I havent changed it since I owned the car which is about 4 years now and I dont now know when or even if its ever been changed.

Would a clogged fuel filter or just an old fuel filter cause something like this? I dont have a fuel filter but havent got around to putting it in.

 

[heckles]

You can check the coil with an ohm meter, check the resistance across the primary and secondary circuits. and I never heard of a fuel filter causing backfire but Im sure changing it wouldnt hurt, especially after four yrs. it should be nice and restricted possibly rusty.

 

[LandoAWD]

On those what should I keep them at .30?

.28

 

[xrobbx03]

ok so i just got some new plugs. BPR6ES single prongs and gapped them to .28. The plugs that I took out of there were already pretty black and they only been in there for about a month.

But after the plug switch it still does the same thing.

Pulls fine up until about 5k then poof poof poof and power dies of..Car still doesnt buck or shut of though.

 

[Defiant]

I just bought the wires about a month ago if that.

Well, was it doing this with the old wires? Nothing says brand-new wires can't fail.

How do I check if the coil pack is bad?

Easiest way is to swap with other known good ones.

do you think it could have anything to do with the fuel filter? I havent changed it since I owned the car which is about 4 years now and I dont now know when or even if its ever been changed.

Could be that simple. But I don't know if the coffee-can DSMs use for a fuel filter will ever clog up, unless you got a shady load of gas.

Would a clogged fuel filter or just an old fuel filter cause something like this?

Could, yes.

I dont have a fuel filter but havent got around to putting it in.

Awfully dark at night, isn't it? WTF

 

[xrobbx03]

I tested my coil pack last night and got 1.6 on the primary and 15k on the coils themselves. So i think it i can rule that out.

I think my car is running rich in the high rpm range. I took out my plugs las night to take a look and the brand new ones i put in were starting to get black after a days use.

I think i might try turning down the fuel pressure and see how that goes.

I had a buddy come by last night and take a look with me never really noticed it until last night but my tailpipe smelled a little like gas. So he seemed to think from that and what it sounded like when I got on it that I was running rich.

Im off today so hopefully i get a chance to play around with it a little.

 

[dsm_Prince]

Im having the same problem. And its also a 97 gst . Could dit be the wastegate?

 

[LandoAWD]

I tested my coil pack last night and got 1.6 on the primary and 15k on the coils themselves. So i think it i can rule that out.

I think my car is running rich in the high rpm range. I took out my plugs las night to take a look and the brand new ones i put in were starting to get black after a days use.

I think i might try turning down the fuel pressure and see how that goes.

I had a buddy come by last night and take a look with me never really noticed it until last night but my tailpipe smelled a little like gas. So he seemed to think from that and what it sounded like when I got on it that I was running rich.

Im off today so hopefully i get a chance to play around with it a little.

I have to ask...are you just guessing randomly?

What is your FP now? What are your O2s doing at idle? What are they doing at cruise? WOT? What are your fuel trims like?

"I think" = our next thread about how DSMs are unreliable POS cars.

 

[xrobbx03]

I have to ask...are you just guessing randomly?

What is your FP now? What are your O2s doing at idle? What are they doing at cruise? WOT? What are your fuel trims like?

"I think" = our next thread about how DSMs are unreliable POS cars.

the voltage of the O2 is fluctuating at idle. I need to do some logs to see whats going on at cruise and WOT.
Fuel Pressure is set at the stock setting 34 Psi.

I am going to go through and check my pipes again...Again would a boost leak cause this?
Maybe I missed something. Could the MAS be seeing a certain amount of air coming into the engine and sending fuel to match that, but because of a leak or leaks in the piping not enough of that intially measured air isnt getting to the engine causing a bad airf/fuel ratio and a result of running rich?