Need help with misfiring
Thread Starter
1st Gear
Joined: Aug 2012
Posts: 1
Likes: 0
Need help with misfiring
First off, im a novice when it comes to auto-mechanics
Recently i have been able to get my l98 vette started (distributor cap & rotor and ignition coil problems) but when it starts the engine will misfire, it does not idle, i have to pump the throttle to keep it alive but after a minute or so it will die
I believe it has something to do with the valves sticking or bad head gasket because sometimes when i start it smoke will come out of the bottom of the right valve cover
If you think it might something else please let me know or if you could tell me step by step (or a link to a thread/website that does) how to clean and reseal the valves that would help too
Heres a video of the engine misfiring and smoking alittle at the end
sound quality does suck though, sorry:
https://www.youtube.com/watch?v=-TXq...U&feature=plcp
Recently i have been able to get my l98 vette started (distributor cap & rotor and ignition coil problems) but when it starts the engine will misfire, it does not idle, i have to pump the throttle to keep it alive but after a minute or so it will die
I believe it has something to do with the valves sticking or bad head gasket because sometimes when i start it smoke will come out of the bottom of the right valve cover
If you think it might something else please let me know or if you could tell me step by step (or a link to a thread/website that does) how to clean and reseal the valves that would help too
Heres a video of the engine misfiring and smoking alittle at the end
sound quality does suck though, sorry:
https://www.youtube.com/watch?v=-TXq...U&feature=plcp
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
First of all, everyone was a novice at some time, so do not let that hold you back. If you are willing then you are able.
Before doing anything else, educate yourself. Go get a REAL FSM set. Its well worth the $100 you'll spend on these 2 books. Thats how you evolve from novice to knowlegable and able.
Without knowing what the engines sensors are seeing or doing its impossible to guess whats wrong. Jumping to a conclusion about valves is foolish...there are a hundred other things on a computer controlled engine that will cause it to misfire and backfire and smoke. 99% are simple adjustments.
Get your FSM set and THEN start with adjustments. Until you know things are set right, its pointless to worry about valves or valve seals.
BTW... (valves) is MAJOR, so go thru the process before digging that deep into your pocket !
Before doing anything else, educate yourself. Go get a REAL FSM set. Its well worth the $100 you'll spend on these 2 books. Thats how you evolve from novice to knowlegable and able.
Without knowing what the engines sensors are seeing or doing its impossible to guess whats wrong. Jumping to a conclusion about valves is foolish...there are a hundred other things on a computer controlled engine that will cause it to misfire and backfire and smoke. 99% are simple adjustments.
Get your FSM set and THEN start with adjustments. Until you know things are set right, its pointless to worry about valves or valve seals.
BTW... (valves) is MAJOR, so go thru the process before digging that deep into your pocket !
Advanced
Joined: Jun 2012
Posts: 91
Likes: 0
From: Texas
Possible it could be a timing issue. Have you done anything that would comprimise timing? Plug wires ^, or anything like that. Could be that one is mixed up. The smoke is hard to tell but its possible its just coming from a leaking manifold. Do the tail pipes puff smoke when starting? Maybe leaking valve seals and burning on that oil on start but very doubtfully has anything to do with the mis-fire. Did this just happen one day or over time?
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
If this problem began with the ignition work, I agree with those who suggested an issue with the distributor and/or wires.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
If you have two spark plug wires crossed the engine will run pretty well on 6 cylinders. One way to tell if this is a problem is to measure the temperature of the exhaust manifolds right where they attach to the heads.
If you don't have an infrared thermometer: I saw a post recently where the guy ran his car (started cold) for 30 seconds or so and then felt the exhaust manifolds with his fingers.
Or you can get one of these guys:
http://www.harborfreight.com/infrare...ter-93984.html
http://www.harborfreight.com/non-con...ter-96451.html
If you don't have an infrared thermometer: I saw a post recently where the guy ran his car (started cold) for 30 seconds or so and then felt the exhaust manifolds with his fingers.
Or you can get one of these guys:
http://www.harborfreight.com/infrare...ter-93984.html
http://www.harborfreight.com/non-con...ter-96451.html
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Check the plug wires around the distributor cap / at the plugs as people have mentioned above...1 8 4 3 6 5 7 2
Did you have the distributor out? If you did, and the plug wires aren't crossed, are you sure you didn't drop it in a tooth off?
What is the base timing set at? Did you set it correctly?
Did you have the distributor out? If you did, and the plug wires aren't crossed, are you sure you didn't drop it in a tooth off?
What is the base timing set at? Did you set it correctly?
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