Help. Misfiring
05-29-16, 06:29 AM
#1
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Help. Misfiring
Well I have a 2004 gs300 and about 8 months ago I started getting a cel for ramdom cylinder misfire at 5800-6000 rpm. I changed plugs, used ngk iridiums. While doing this I also cleaned the throttle body as well as maf sensor. This changed nothing so, I the proceeded to replace all the coil packs. Still no change. Then the other day I was driving and all of a sudden My car starts missing badly. You can hear it and it has no power. I go back home and run my scanner, grt random cylinder misfire, cylinder 1 misfire, and cylinder 4 misfire. What should I start checking? What could cause this all of a sudden? Thanks for any help.
05-29-16, 01:11 PM
#2
First 2 things I can think of: How do the plugs look when you remove them? Is there any oil getting into the cylinder, could have some worn seals that need to be replaced.
The other, possibly a dirty injector issue. Run an injector cleaner and see if it helps any.
Being that its in only 2 cylinders, It wouldnt be anything like a vacuum leak or o2 sensor since those would affect all the cylinders. You need to focus on the 2 cylinders alone such as the 2 ideas I mention. Other stuff like compression and such too, but start with the simple stuff first.
Also, check and make sure the wires 'snapped' properly in place on the plugs. I had a similar issue and actually and after almost a year later from doing my tune up, I got a nasty misfire and found that one of the plugs was actually sitting on top of the valve cover. It popped completely off.
The other, possibly a dirty injector issue. Run an injector cleaner and see if it helps any.
Being that its in only 2 cylinders, It wouldnt be anything like a vacuum leak or o2 sensor since those would affect all the cylinders. You need to focus on the 2 cylinders alone such as the 2 ideas I mention. Other stuff like compression and such too, but start with the simple stuff first.
Also, check and make sure the wires 'snapped' properly in place on the plugs. I had a similar issue and actually and after almost a year later from doing my tune up, I got a nasty misfire and found that one of the plugs was actually sitting on top of the valve cover. It popped completely off.
05-29-16, 02:18 PM
#3
First 2 things I can think of: How do the plugs look when you remove them? Is there any oil getting into the cylinder, could have some worn seals that need to be replaced.
The other, possibly a dirty injector issue. Run an injector cleaner and see if it helps any.
Being that its in only 2 cylinders, It wouldnt be anything like a vacuum leak or o2 sensor since those would affect all the cylinders. You need to focus on the 2 cylinders alone such as the 2 ideas I mention. Other stuff like compression and such too, but start with the simple stuff first.
Also, check and make sure the wires 'snapped' properly in place on the plugs. I had a similar issue and actually and after almost a year later from doing my tune up, I got a nasty misfire and found that one of the plugs was actually sitting on top of the valve cover. It popped completely off.
The other, possibly a dirty injector issue. Run an injector cleaner and see if it helps any.
Being that its in only 2 cylinders, It wouldnt be anything like a vacuum leak or o2 sensor since those would affect all the cylinders. You need to focus on the 2 cylinders alone such as the 2 ideas I mention. Other stuff like compression and such too, but start with the simple stuff first.
Also, check and make sure the wires 'snapped' properly in place on the plugs. I had a similar issue and actually and after almost a year later from doing my tune up, I got a nasty misfire and found that one of the plugs was actually sitting on top of the valve cover. It popped completely off.
He knows what he is talking about. The wires that leading to the coils that you need to check on piston 1 and 4, is something like the picture I put here. It is for you to have a better idea of what Mr. jokster is trying to explain to you.
Check the terminal wires on the plugs. With the heat of the engine the cover that protects the internal wires, over time are roasted or break in pieces and cause the wires to come together and create the codes.
Check also, the plastic that coves the wires from the coils to the other piston. The wires also break inside the cover and you no see it at all. Take you time and look very well in that area. Good luck.<br/>
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