I changed the EGR valve, No difference, Still does intake backfire, It's making like a ticking noise like a clock from the intake and when I step on the gas it backfires really loud from there. Guy at Chevy dealer told me that my timing chain could be shot but it's in time and stuff. And it runs and idles good, It didn't make this noise b4 I put the engine in.

 

Timing chain worn and streched... you can compensate by advanceing it up a few degree's...

Advance till it pings, then bring it back a little.

it works, but it's no substitute for getting it fixed...

Learn from my father! (I know this is a Toyota story, but it's relevant)... he let a timing chain go too long (200K+) and it wore a hole in the water jacket... it was so loose it was slapping into it and eventually ate it away... water in oil, oil in water... washed out the bearings, killed an engine that would have lasted forever.

On a side note... I'm moving out of my mothers place and in with my father... I also got accepted to NJIT's College of Computing Sciences... I'm gunna be a computer geek guys!!!

 

Timming Chain.... I had the same symptoms... How does it run at 3000RPMS or higher?

 

Still does the backfire but not as loud, It's really loud at about 2000 or 3000

 

2 words before I laugh
Distributor
Coil

 

You think my distributor or coil is shot? Would this cause Intake backfire?

 

that "ticking" noise close to teh intake under the fuel rail is it ... then i guess it can be bad lifters...

 

It did not make this noise before the swap, The engine runs and idles so good you can barely hear it, It's just when u rev that I get that ****en intake backfire

 

Noise is following path of least resistance.
Cause could be electrical advance set up or poor electrics.
BUT it's electrical.
WHY?
It fails under pressure.
RPM increase

 

I take that back
Your chain is so stretched, it goes outta timing when it is stressed, then it "slips" back into synch.
Like a pants belt ya whip, that "S" shape.
AND of course you never changed the timing chain when ya did the engine swap like I said, $ & ZERO Effort.
NOW........

 

Welcome to computer geek land, Xeno! You'll love the classes about useless theory, and it's so exciting to learn dead languages just so you can "learn how to program in other langauges". I recently wrote a program in Scheme. Yep, I never heard of it either. Ugh, the class drives me nuts. We just did C and C++ (which I knew), but now we're doing Prolog! I picked up Javascript & ASP in a week, and they want to teach me how to learn new PL's? Geez.

And 85CamaroRulz, you might as well do the chain. Did you ever check the balancer ring's mark to see if it lines up with 0 on the timing scale when #1's at TDC?

You say it backfires when you rev it up; does it backfire when you drive?

Did you check for an intermittant fuel pump/ECM supply? Look at the weatherpack'd fuse on the passenger side upper frame rail, near the front of the car. There's a fuse with a red and brown wire coming from it. Check it to make sure you've got +12 constantly, even while wiggling the red & brown wires. My car died once, and if it ran, it backfired like crazy. I was down the road from my mech, and had it towed 1/2 mile to him. He traced it to "no supply to fuel pump relay". I took it back (he said he could start tracing wires but it'd cost me a ton) after rigging the fuel pump relay to be on, and found out I had a bad ring terminal at the positive junction block (pass side of radiator support). I replaced the ring terminal and I was good to go.

 

My car backfires when I rev it up, I also know how I have to fix it. I have to break the damn motor in then it will stop once it has some miles on it.OBTW it does it every now and then not constanty.