Misfiring!!!

[babiebluboi]

My car was misfiring like crazy. I look at my boost gauge and if I go above 0, the car bogs and then misfires. The RPM won't climb if the car bogs. I found out that my intercooler was cracked and the BOV had a vacuum leak. So I bought a new intercooler and new BOV. I just got them both installed today. The car is running a little bit better now that I can have positive boost.......BUT the car is still misfiring and like 5000 RPM. I was hit the gas kinda hard and now there's a ticking noise under the hood. It sounds like it's coming from the head. When I gas it now, the ticking gets more rapid the higher RPM it gets to. HELP! I DON'T KNOW WHAT'S WRONG!!!

 

[Fastbanker]

9 times out of 10, its either the spark plug wires or spark plugs.

 

[alex]

Yeah, most likely they are the spark plugs or the the spark plug wires. Get the NGK spark plugs, they seem to do a nice job compared to the rest of them.

 

[SkyLineGtR-R34]

Just replace the wires and sparkplugs as few others said already.

 

[alex]

After you replaced the blow off valve and the intercooler, did you do another boost leak test?

 

[andymoraitis]

Alex raises a very important point in his post. Start wih a boost leak test. Also, the other posters are correct in advising you to put in a new set of plugs and wires. I had similar issues to yours when I first bought my car and changing the plugs and wires worked wonders.

A set of NGK wires will work well for your application. If you run stock boost levels, NGK BPR6ES will work and if you run higher boost than say 15-16psi, switch to NGK BPR7ES. Avoid platinum plugs at all costs and make sure they're gapped correctly to .028.

Now how about that boost leak test?

Andy

 

[babiebluboi]

I changed the spark plugs (NGK) and wires (OBX) about 2-3 months ago. Maybe I need to change them again? My car literally fried the Bosch Platinum spark plugs (I heard those aren't meant for Japanese cars anyways). I think my spark plug wires are okay (unless one of you know how to tell if they're bad or not). I don't mind changing the spark plugs again ### they're cheap anyways.

Second thing, how do you do a boost leak test?

 

[andymoraitis]

Boost leak test info can be found here:

http://www.vfaq.com

Look under the Intake section and it will show you how to build a tester and test for leaks.

Andy

 

[andytalon]

Did you gap the plugs?

 

[SkyLineGtR-R34]

I changed the spark plugs (NGK) and wires (OBX) about 2-3 months ago. Maybe I need to change them again? My car literally fried the Bosch Platinum spark plugs (I heard those aren't meant for Japanese cars anyways). I think my spark plug wires are okay (unless one of you know how to tell if they're bad or not). I don't mind changing the spark plugs again ### they're cheap anyways.

Second thing, how do you do a boost leak test?

My car started missfiring and I took it to a shop to check what's going on.
The mechanic changed the plugs and wires and it ran nice. After 3 months same thing again. So I go to NAPA get the best wires and NGK plugs and do it my self. When I took off the old wires, the one on cylinder one was all burnt and only hanging on a pice of metal wire a little bit thicker than a hair piece.
If you don't plan to go with performance wires, go to NAPA and get ones from them, not the ones you can find at autozone.
As for the plugs, get NGK BPR6ES if you don't have any mods, if you do then get BPR7ES.
And as someone already said do a boost leak test.

 

[marq95gst]

I had bad misfires too. I changed out the plugs and put new ones (bpr7es)....still misfiring. Then replaced my magnacores with ngk wires...misfires less, but still sometimes. THEN, I bought a can of Sea Foam engine cleaner. I sucked it in through a vacuum hose (the one connected to the BOV. After that, NO MORE MISFIRES!

Just something else to consider trying. Also, the can is pretty cheap and it cleans everything out. But then I do have 158,000miles on my GST (so I definately needed that), and it's still going strong.




..update....car misfires bad....cylinders 1 and 2 no fire!!!!