Getting a backfire in the intake, car won't start, video inside!

[Haraise]

Just did the water pump and cleaned up under the intake, car sat for a while (previous owner and me), but just got everything back together, and now the car acts like it's backfiring in the intake? o.O

Here's a video:
http://www.youtube.com/watch?v=2CqPkB2Teuo

Pics of where the ICV is going, tube with the sticker is the ICV line:



This is where it plugs into the tube:



Any idea what this could be?

[nicknikolovski]

Check for an air leak, vacuum leak, low fuel pressure.

[Haraise]

Checked the fuel by taking off the hose and cranked it, some fuel shot out so i don't think that's the issue.

As far as the lines go for air, there's the FPR line that i just put back on, the ICV line that i just put back on, then the crankcase vent that i blocked up. i think that's all there is to the system, other than the brake booster, which i didn't take off. Why would an air leak cause a backfire like that though?

[dinu.negrean]

Large vacum leaks causes backfire, that's for sure. But it should start, backfire and die right away. Looks like a fuel supply problem to me. When you crank it it should throw fuel big time.

You should also check if the sparkplug lines are plugged in the correct order

And blocking the crankcase vent is definetly not a good idea.

[DesktopDave]

I wouldn't block the crank vent either.  The pressure in the crankcase will cause blow-back.  I'd suspect that's the cause...I'd test my guess with an inline carb-style fuel filter instead of plugging it.

[Haraise]

Sorry, i meant i plugged up where the crankcase vent feeds into the throttle, not on the valve cover.

So, i will see what i can do about fuel, thank you. Maybe it just needs new gas.

[DesktopDave]

Run a stomp test to see what comes up.  I'd double-check that the fuel hoses aren't swapped.  I might pull the cyl head cover to take a look at the cams, timing chain, etc. just to see if they're all still pointed the right way.

If that all looks OK, maybe run a compression test?  I'm hoping it's not a stuck valve or anything expensive like that.

[Haraise]

How can one tell if the fuel hoses are swapped?

What's a stomp test?

[Haraise]

Alright, trying to verify i have the fuel hoses by the intake hooked up correctly (not swapped).

Coming from the firewall, the TOP line goes to a hose, which connects to a hardline which has a TURN towards the FPR. the BOTTOM line connects to a hose that has a STRAIGHT hardline.

So, top line has a angle to the hardline by the intake, bottom line has a straight hardline.

Is this right?

[Haraise]

Got it, my spark plugs were in the wrong order, i thought i needed to put them on the engine 1342. -.-

Car won't idle though, will run fine if i stay on the gas, but if i don't it starts up nice and smooth then dies out. Any ideas?

[DesktopDave]

Check the ICV to see if it's running.  Should buzz softly or flick open when it gets 12VDC.  You can also use a 9v battery to test.  How clean is the throttle body?

[Haraise]

Throttle body is pretty clean, and the ICV is definitely working, if i put my finger over the hole that connects to the intake tube, it has some suction.

[DesktopDave]

Did you see if the ICV door is moving?  It flicks when you put a battery on it.  It'll likely have suction while the car runs even if it's non-functional.

[Haraise]

Alright, GOT IT. Found a vacuum leak from what i thought was a coolant line.

Thanks everyone!

Now my driver's side rear window will roll down, but not up... looks like the car is going back in the garage. Any ideas there? >.>

[DesktopDave]

Clean the buttons.  I use a bit of fine sandpaper.