bubble backfire sound,out of muffler

[1990civicdxhb]

I have a weird sound coming out of my muffler & my brothers nissan does it too,its like a bubble backfire out of the muffler,
it done it before & after I cut the cat off,
it does it when I start the car,cold or hot,I dont need to hit the gas,
but when I do,it does it even more,(as the idle goes down)
my computers not showing any codes,practicly everythings new,besides my fuel pump/tranny...
the motor sounds good,perfect idle,but you can go back to the muffler & hear,bubp,bubp,bubp,,,,bubpbubp,,...
its not a big problem,but I would like to have a nice smooth performance sound instead of having that crapy idle noise,
sounds weird,but I think it started doing it when I put my apc muffler on,
but my brother has a powertech muffler & his does it too,
I think I've read a post somewhere on this & never got to reading it,
someone was saying it was a lazy fuel pump,
but if anyone has any clues of what it is or what I should do let me know,

[nyfinest32]

yea i'd like to know how to fix this problem also. same thing happens with my hatch

[Hybrid1990crx]

Sounds like an exhaust leak.

[CRXsiZCpa]

Maybe something with the valves? Does it seem to run okay?

[1990civicdxhb]

it runs fine,I've adjusted the valves already,
but I do have an exhaust leak,from my headers,but I got my exhaust before my headers,
& when I put my exhaust on I put it on with clamps,soon had it welded,but the weld was never air tight(all the way around the pipe,)
so maybe it is a exhaust leak,
my brothers nissan also has a leak near the manifold,
I'm waiting to get the money to have a fresh straight pipe all the way back,
but I have no idea of what it could be,
thx for any suggestions,

[nyfinest32]

well when i installed my new exhaust it had that problem, so im not sure its an leak

[93_R/T_TT_Stealth]

i had this prob in one of my cars - it did it when i had no exhaust from down pipe back an i also had small fuel leak - so i would assume its one of those - i think it might be the fuel - there might be a pause in the fuel pressure when u try to start it an its making a bloop noise right? an after the fuel builds up it makes that noise then starts.....

[nyfinest32]

mine makes the bubble noise when its idling

[93_R/T_TT_Stealth]

wheres your exhuast leak? is it the header?

[nyfinest32]

im not sure, but im guessing it is

[1990civicdxhb]

Originally Posted by 93_R/T_TT_Stealth

wheres your exhuast leak? is it the header?

yes,I have a leak in the headers,4-2(gasket)-1
but it was doing it before I cut the cat & before I put headers on,
but it never did start until I put the exhaust on,
I started with taking the factory muffler off & putting a staright pipe on it,it made a little better sound,but I've always had a leak,because I had it held on with clamps,so even when I took that off & put a performance muffler on,it still had a leak,because the person who welded it on,didnt weld all the way around the pipe,so it did have a leak,
& when I put headers on & straight pipe,I've always seemed to have a leak,
& Ive had all the pipes finally welded together,except for the last leak,& its between the headers,because I didnt have any gaskets,
so maybe it is a exhaust leak,
& I'm pretty sure I dont have a fuel leak & if I did,it would be coming out the tank,because my cars motor is realllly clean,& I make shore everythings good in good shape,
& it only does it as it idels or when I shift(let off the gas)
it doesnt affect the way I drive,the pedal,fuel,but it may affect the performance(i dont know)
thx for all the suggestions--

[93_R/T_TT_Stealth]

so it sounds like you just need to put a gasket on the header - i would try that an ya never know it might stop - plus they aint really expensive plus ya need one....an exhaust leak causes power lost reguardless ...hope ya get her purrrin good,
good luck