My car stumbles at high RPM's and at high boost?

I just replaced my plugs, did I not put them in all the way? Are they supposed to lock tight? I screwed them in until it became difficult to turn, but I wasn't sure if they would lock once they're all the way in?

Any other possibilities?

 

Check your spark plug wires

 

You should use Anti-sieze compound on the threads and torque them to spec (9.5-13ft.lbs). This will prevent any possibility of breakage when removed - known problem. Also make sure you burp your boots! I use high voltage silicone paste in the boot to prevent water from entering and burping is really important. Also make sure you have the trailing and leading plugs in the correct place - that could cause stumbles. Trailing is top BUR9EQP (blue stripes) and Leading is bottom BUR7EQP. Good luck.

 

You also might be hitting a fuel cut.

 

Ditto reckless, do you have a lot of mods? U might need bigger injectors for more fuel

 

When is the last time you changed your fuel filter argh!

 

this has started to happen to me too...only for me it has happened in the low and high rpm range also. Usually happens under higher boost and when its cold...The car has 48k miles and prolly needs fuel filter and plugs replacement...

any other suggestions? Boost cut / fuel cut?

is this harmful

Thanks

 

Well, it just started happening...and Ironically it was just after I chanegd my plus, I went to 9's all around because I have a lot of mods.....

But are the plugs supposed to screw in tight, like until you can't turn them anymore? I kinda noticed that one or two looked like they weren't in as far, but they were becoming tight to turn so I didn't want to strip them......

 

You bet its harmful! A clogged fuel filter provides one of the classic Rotary destruction techniques! No fuel + high boost + high RPM = BIG Ping
Be careful!

 

The Trailing or top plug has a raised edge around part of the plug so it looks like it goes in further. If you are in doubt pull them again check the threads put on a little anti-sieze and thread them in by hand. Make sure they go in straight then use a socket and torque very lightly. The compression washer makes the seal.

 

try going back to 9's and 7's and see what happens.


see ya,

car 53

 

Let us know the results. I have a similar problem, but it is just at a certain RPM, not higher or lower. This makes me think it's not the filter, but i'm gonna change it out anyway. Easy insurance.
~Tom

 

There is nothing easy about changing your fuel filter if its in the stock position! Be prepaired to wear, sniff and possible drink gas when you pull off the hoses, which can only be got while giving a bear hug to the Diff. and looking directly up! First time 2-3hrs. If you relocate to the engine compartment (KN Billet type) you only have to remove the filter, insert a short straight inline coupling and mount the new filter oh and you need about a foot of high pressure fuel line.