2001 tacoma backfire out of the air box

Ok Guys I need help. I have a 2001 tacoma 6cyl. When i get to 4 rpm it backfires out of the air box. The the truck runs fine otherwise and has plenty of power. Only when on demand like passing another vehicle and i excellerate to 4 rpm is when i hear the sound. Changed the plugs and wires. Still doing it. Going to change the fuel filter today. No engine light and no codes. Anyone know whats going on or had this happen to them?

 

I think first an ignition timing check, followed by a leakdown test should be a good start...

Check timing at idle then see if it advances correctly. A leakdown test should find a bad valve. Not sure about the best way to verify cam timing without going into the timing belt area.

Howard

 

ok. So I changed the plugs again. Also checked the timing. Everything is ok. What I did notice now is that there is black smoke that comes out of the tail pipe when it goes to a backfire. Any suggestion?

 

Another idea...

A clogged or loose honeycomb in a cat can cause that symptom, when flow really gets up there it can't push it out and the intake gets really really loud. Normally a carbon clog gives the symptoms you're describing (only a problem at high rpm). I was less lucky, I once had a honeycomb of a cheap aftermarket unit break loose and lodge sideways into the outlet and it effectively set my 1.6L engine's redline at 2000 rpm.

 

ok. so i took the cat off of the vehicle. Running with only a muffler. Still having the same problem. Ill check for the skip tooth. Im running out of options here

 

cam and the belt are in good shape. No problems there. Damn. Anyone else

 

I wish I could help you. You do realize this is the 2nd gen forum right?

 

That is funny, he asked the people who don't drive 5VZs what's wrong with his

I'm out of ideas too.

 

check your injectors to see if one is pushin too much fuel?

 

Did you put the plugs back in the right order? After changing them? Timing, adjust valves.

 

Did you do the leakdown test yet? My money says bad or non-seating valve. Seafoam may cure the latter.

 

Ok

 

ok. So I changed the plugs again. Also checked the timing. Everything is ok. What I did notice now is that there is black smoke that comes out of the tail pipe when it goes to a backfire. Any suggestion?

 

ok. so i took the cat off of the vehicle. Running with only a muffler. Still having the same problem. Im running out of options here. The cam and timing belt are in good shape. No problems there. Damn. Anyone?

 

honestly it sounds like a timing problem, it happened to my truck when we first put the motor in (got it for 500 with a seized engine) had to fix the timing then she ran like a top, of course mine did it at idle. sorry if I'm not help.

 

I checked the timing twice and Im still getting the same symptoms. Thank you tho

 

Got me stumped. Try reseting the ECU (disconnect the battery and depress the brake or just wait a few min).

You might want to look into a shop.

 

something is not right! now i always heard this that you can and will blow up your cats with the backfires!
dont know if your timing belt is dying and needs to be changed
taking off the cats and your CEL should be lite up like a xmas tree
have you changed plugs recently?

 

check pcv

 

check egr