View Full Version : nitrous backfire


2000slpss
09-22-2005, 02:50 PM
ok so im at about 3k in 3rd gear(m6) and i hit my arm switch and go wide open. it pulls fairly smooth through 3rd but when i go to shift into 4th i hear this very loud pop and i knew it backfired through the intake . the engien died and i pulled off to the side of the road. popped the hood and the manifold was fine cracked the airbox though. i start checking things and realize what happened. i had te fuel line fro mthe solenoid to the nozzle covered i nplastic tubing but i guess it moved and whe ni hit the nitrous the line arched on my positive battery terminal melting the tubing inside the braided line. so now my ses light is on got the codes scanned at autozone and i have a p0300 the engine is also ticking alot louder than before. what would likely causes for the ticking be? im going to pull my plugs and check them later on today. any tips would be greatly appreciated

Nitro Dave's Nitrous Outlet
09-22-2005, 03:09 PM
Ouch,
So the fuel line melted?
Pull the plugs and do a compression test.
Dave

NitrousDirect
09-22-2005, 03:11 PM
That's a first I ever heard of a line touching battery terminals and melting.. you're lucky it didn't burst into flames

2000slpss
09-22-2005, 03:27 PM
yeah i know im really lucky. i tested it later on yesterday and fuel just dribbled out in little tiny spurts from the nozzle so it went way lean

badls1
09-22-2005, 05:27 PM
you probably melted the plug

Armageddon
09-22-2005, 05:44 PM
That's a first I ever heard of a line touching battery terminals and melting.. you're lucky it didn't burst into flames

I had mine touch the alternator cable when I had the alternator relocated. It looked fine from the outside but it melted the rubber on the inside...

Airwolf
09-22-2005, 06:57 PM
SEE!!! Nitrous is not dangerous, that damn battery is!!!

Wow. Very scary!!!!
All kidding aside. Glad everything is OK. That could have been VERY BAD.

DynotuneN2O
09-23-2005, 10:48 PM
I agree, probably just a plug...

2000slpss
09-24-2005, 01:48 AM
well started disassembling today. was gonna do a compression check but my cylinder 3 spark plug was frozen in the head. so i decide to just pull the heads and check everything. i have more than half of my pushrods bent 5 of which i could see plainly without rolling them on a table. we finally manage to get the plug out the insulator was cracked and the ground was damaged. cylinders 1 and 6 have some damage and then a few other pistons have marks from what appears to be the intake valves. im posting pics in another post in the internal section. any tips for which direction i should head?

red90cobra
09-24-2005, 01:52 AM
built bottom end and some heads

2000slpss
09-24-2005, 02:25 AM
unfortunately im only 19 and im in school. cant afford tooo much right now heres pics http://photobucket.com/albums/y209/slpss2000/

red90cobra
09-24-2005, 02:48 AM
how much damage have been done to the cylinders? I would say if nothing major you could just throw the heads back on there. take the cylinder heads to the machine shop first and see if you bent a valve. see what it's going to cost to fix. depending what it cost you just get another set of heads complete for 150. and throw those up there. as for your short block little smilies on the piston is fine. i've had a few and still ran 10.35@ 136. it'll work since you don't have too much money.

2000slpss
09-24-2005, 02:52 AM
the cylinder walls are perfectly fine. i have a friend who works at local machine shop so im gonna have them check everything over for me.

red90cobra
09-24-2005, 03:38 AM
the cylinder walls are perfectly fine. i have a friend who works at local machine shop so im gonna have them check everything over for me.

that's good news thought there was because you post this earlier:

well started disassembling today. was gonna do a compression check but my cylinder 3 spark plug was frozen in the head. so i decide to just pull the heads and check everything. i have more than half of my pushrods bent 5 of which i could see plainly without rolling them on a table. we finally manage to get the plug out the insulator was cracked and the ground was damaged. cylinders 1 and 6 have some damage and then a few other pistons have marks from what appears to be the intake valves. im posting pics in another post in the internal section. any tips for which direction i should head?

well good luck with it

2000slpss
09-24-2005, 11:30 AM
oooo should have been a little clearer pistons 1 and 6 are damaged

LeMansBlue04
09-24-2005, 12:16 PM
Can I offer another opinion?

I can't think of any reason an NO2 lean out followed by a backfire would cause valves to kiss pistons. I think it's more likely that the valve to piston clearance problem has been there for a while. The only exception I can think of is if some how, some way, the cam timing was compromised by damaged timing gear.



I don't know what cam you are running. If it's fairly aggressive then clay the valves before you put it back together. If it's mild, start looking at the timing chain and gears for damage.

:judge:

The Sad
09-24-2005, 01:38 PM
:stupid:

I was wondering how the nitrous caused the pistons to contact the valves.

red90cobra
09-24-2005, 01:40 PM
what valve springs? more than likely weak valve spring pressure at high rpm.

2000slpss
09-24-2005, 02:22 PM
i was racing on the highway a mointh or 2 ago and at redline going from 4th to 5th i missed and got 3rd and mechanically over revved it pretty hard. i pulled all the pushrods and they were still straight so i reassembled. im guessing thats when the valves kissed the pistons

red90cobra
09-25-2005, 12:42 AM
i was racing on the highway a mointh or 2 ago and at redline going from 4th to 5th i missed and got 3rd and mechanically over revved it pretty hard. i pulled all the pushrods and they were still straight so i reassembled. im guessing thats when the valves kissed the pistons


that would do it but usually they bend push rods though