Car backfires

[foofers]

My car backfires and cant find the problem

 

[sek_phok]

Does yourcar overheat or heat up? Have you done a compression test? Tried for any boost leaks?

 

[9!'clipseDOHC]

We need more info. Does it backfire while driving? During shifts? When you turn it off? What mods have been done to the car?

 

[foofers]

It does it in 3rd gear going to 80mph.
i have just put intercooler piping and exhaust.
i haven't done any test to it
but i got told that my waste gate connections were not right i don't know if its true

 

[LiquidX]

Have you done a boost leak test and I'm assuming you are boosting when going to 80 when it happens?

 

[9!'clipseDOHC]

It does it in 3rd gear going to 80mph.
i have just put intercooler piping and exhaust.
i haven't done any test to it
but i got told that my waste gate connections were not right i don't know if its true

A backfire is the basically combustion happening outside of the of the combustion chamber. Does it sound like it is happening in the exhaust (behind the car) or in the intake (in the engine bay). If this is happing while driving (is it cruising or accelerating), I would first suspect a problem with your AFR (Air Fuel Ratio) (running very rich or lean), a problem with your ignition timing (the valves opening before the burn is complete), or a problem with your ignition system (not burning all of the fuel in the chamber so when the exhaust valves open the fuel is ignited in the exhaust).

Does the CEL (Check Engine Light) come on when this happens or is it always on? Are you running the stock injectors/turbo? Make sure your plugs and wires are in good condition and if they aren't replace them with stock NGK's. Check your fuel system for leaks, make sure the FPR (Fuel Pressure Regulator) is hooked up properly, make sure your fuel filter is flowing, replace if it isn't. Check your ignition timing to make sure it is set properly at 5* BTDC (Before Top Dead Center). I would also do a boost leak test to make sure you don't have any boost or vacuum leaks as they can effect your AFR and mess with your FPR.

 

[foofers]

It happens when i am accelerating runs good while cruising and my check engine light is not on
imma go for the boost leak check what do you recommended i should go or do?

 

[Archer Fabrications]

google or search on the forum, boost leak tester. you basically make one of those (hard ware store) and run compressed air through the turbo and intake system, if you hear seeping then find it and fix the leak, if you hear seeping and dont know where its comming from, spray simple green in all the connecting pieces (couplers) on the intake system or intercooler system. if it bubbles when the liquid is on it, its leaking, fix it. you said your CEL is off... but i had backfires when my front o2 sensor was shot, fixed it and my CEL came off. car runs like a champ just from that sensor replaced.

 

[9!'clipseDOHC]

It happens when i am accelerating runs good while cruising and my check engine light is not on
imma go for the boost leak check what do you recommended i should go or do?

Ok. You can make your own boost leak tester with a couple of parts from Home Depot, then you just need an air compressor and s spray bottle with soapy water.

Make your own from hardware store plumbing.

You just need a rubber coupler that will fit around the inlet of your compressor. Then, cap off the other end and install a schrader valve in the cap. And you have a boost leak tester that costed less than $10 to make.

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How To: Boost leak tester for $5.02 - evolutionm.net
IC Pipe Tester

Does it sound like its backfiring in the engine bay or behind the car?

 

[96talontso]

Happens when i downshift thats normal right?

 

[96talontso]

Its a popping noise though not a backfire

 

[4g63 PowerBlock]

yeah bro, we absolutely recomend a boost leak test, if your too lazy to make your own tester, go on ebay and buy one for about 35 dollars...
haha laziness has a price and well what injectors are you running it may also be cause cause your running to much boost...

same thing happened to me in third at about 4500 RPMS 4th gear at about 4000 rpms
till i did a boost leak test and took care of a MAJOR leak that i had when i upgraded piping.... then... problem solved...

now my 3000 pound monster is spanking ASS