What Is Causing My P0307 Misfire?!?!?!?
What Is Causing My P0307 Misfire?!?!?!? 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
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
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.
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.
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.
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!
Trending Topics
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.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
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.
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
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
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
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
!!!!) 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
#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.
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.