kornfreak_401

iTrader: (77)

I was going down the highway passing cars in 4th at 6,000 rpm and all of a sudden inbetween changes I would get big puffs of smoke come out the back like i blew up when i would go back into 6th. SES lights up for a while then a few minutes later starts to blink. I run the OBDII Scanner and pulls up P0307 #7 cylinder misfire.

1) I replaced the plug. Old plug looked good, only had about 3-5 months of life. cleared the codes and ran engine, still sloppy and puts out P0307 again.

2) Swapped entire coil pack rail with ls1powerhouse's rail. Inspected old pack and looked good. cleared the codes and ran engine, still sloppy and puts out P0307 again.

3) Swapped coil pack #7 pack on my rail with the first one. cleared the codes and ran engine. P0307 DAMN!!!

WHAT CAN I DO NOW??? Seriously people, I need help.

My car is running really sloppy and is smoking like crazy.

How do I run a fuel ingector test on #7?

Do ya'll think it's my valve spring seals? I've put about 16-17K miles since i got the car last FEB.

How can I tell if my seals are bad if I take the valve cover off?

Jerry

Travis99LS1

iTrader: (2)

What color is the smoke coming out??? I'm assuming its black smoke from excessive fuel being burned...my guess would be the injector is either hung open..or is damaged in some way that its allowing fuel to leak..If you still have cats i would not drive it until your pretty much sure you have it fixed...A blinking SES light indicates a catalyst damaging misfire..If you keep driving it, odds are you'll be replacing your cats to.

kornfreak_401

iTrader: (77)

nope no cats, smoke is kinda bluish/grayish.... cats are there but rear O2's are deleated.

Subliminal Hit

iTrader: (63)

try swapping the wire with one of the other cylinders and clear the code, see if it changes cylinders(i.e.p0301). If there is no change then more than likely its the injector. Pull the #7 plug after running it for a little bit (let the heads cool off though) and see/smell if its fuel soaked.

Subliminal Hit

iTrader: (63)

you can also try tapping on the injector with the car running and listen to the idle and see if it clears up. If so, the injector was stuck open and it will probably happen again. You can measure the resistance across the injector even though gm stopped giving specs but I think it should be between like 5-14 ohms, but they can still be bad even if its within specs.

kornfreak_401

iTrader: (77)

thanks guys i'll try that.

any other ideas?

TA TECH

iTrader: (8)

Check the grounds on back of the driver side head. Make sure both bolts are tight! i've saw the same prob before and tightening them fixed it the time I saw that prob! Maybe ya will find it!

autotrix

iTrader: (5)

You should do a hot compression check, a running compression check, and check your injector pulse, unplug and use a test light or noid light if your have one to check the pulse. (10 bucks @ harbor frieght tools) Next Ohm it out. Then if all checks out above, your injector could be clogged and not spraying well. They are easy to remove.

kornfreak_401

iTrader: (77)

thanks for the great advice

kornfreak_401

iTrader: (77)

bump.

EricGTP

If you have an auto tap they will scan for injector pulse width by cylinder.

kornfreak_401

iTrader: (77)

thanks!

01WS6/tamu

iTrader: (37)

Move the injector a hole over and see if the problem moves. You might also get a noid light and see if the computer is controlling the injector, It is possible it could have lost a control line for the injector. Not likely but, I have had it happen.

jeffboy757

iTrader: (14)

i dont think a bad injector would casue smoke to come out the tail pipe. it would just cause stumbling and poor performance. the fact that it blew while high reving is a sign.

when oil gets into the cylinder, its usually from bad valves, rings. and the fact that its #7 cylinder makes me think of the 3
#7 ringland problem. esp it the injectors were clogged up to begin with

Boosted 99 TA

iTrader: (1)

im having a simular problem, i swapped everything and the problem stayed wtih the same cyl. some body asked if i had a ticking noise and i do and they think it maybe coudl be a bent valve or bent pushrod

autotrix

iTrader: (5)

Yeah good point, it was at high RPM, I would bet on those pushrods being bent for sure!

kornfreak_401

iTrader: (77)

thanks guys for a the help. i'm running auto tap tomorrow and doing a compression test. we'll see....

Jerry

kornfreak_401

iTrader: (77)

bump..

kornfreak_401

iTrader: (77)

IT'S DONE. APPARENTLY I mistaked #7 with #8. I did a compression test on #8 thinking it was #7 then I saw the injectors were numbered (DAMN !!!!) Which by the way it was hard as hell getting that tool hooked up properly. After the compression test we (my friend Grant) found the problem. I took the plug out and it was GUNKED, It was full of oil and carbon deposits. #8 was inbetween 160 and 180 psi. #7 didn't even brake 30 psi... I'll be taking the engine out next saturday, new piston and rings. Well since the engine will be out.... forged/spray or heads and cam?

Really, thanks to all that put their $.02 and info.

Jerry

keliente

iTrader: (22)

#8 cylinder is not fun for doing any kind of work to!!

Sorry that this is such an in-depth problem for you. Whenever I read this posts I always hope it's just a plug or an injector or worst case, a pushrod. Personally I would go with heads/cam but it depends on what you want to do with the car.