buckaru part throttle missfire

[frank_ster]

so it started missfiring at idle and part throttle. mi and full throttle it runs perfect.

so i did the usual things like swaping spark plugs and even injectors. no change.
i started noticing the boost gauge flickering when it would missfire so i suspected intake valve.

just pulled int intake and looked at the cam and those 2 lobes for that cyl are a bit rough .. then i pull the lifters and sure engough there is some dammage on them and the intake one looks like the ever so slight slat spot.

now question is should i change that cam? the lobe profile looks ok but its not new looking like the others.
i know i should change all the lifters .

any of you have any experence with that? its a comp cam 504 lift roller.

thanks.

 

[frank_ster]

meh thought about it .. i'll just throw in 2 used lifters and drive it like that.. its just a 200$ engine..

 

[frank_ster]

Week later and 1000 km it seems to be fine !

 

[earlbrown]

You need to pull the engine, tear it down to the bare block, hot tank it, clean the crap out of it, clean the crap out of it again, then build it.

oh yeah, toss any oil coolers before hooking them to the new engine.

 

[earlbrown]

ooooooor, you can keep on riding...

If you choose that route, go ahead and add a turbo to the rebuild.

 

[frank_ster]

^ why?

 

[earlbrown]

Because the grit from the cam lobes are going to make more grit out of your engine. Cycle repeats itself....

By the time you run it to the point of failure, the turbo will chewed up as well.

 

[turbo nasty]

Do it right...pull it and go through it

 

[Heisenberg]

Heck with it - Just pull the motor and swap it for a LS1.
I'll give you 50 bucks for it - if you ship it for free.
Of course, I'll need a guarantee

 

[frank_ster]

but the oil filter is gonna eat that stuff... i had plenty grit thrown through the engine when the timing chane ate its self last time.. and the bearings still look like brand new. ls1 wont fit.. gotta keep 4wd

 

[frank_ster]

Did another 500 km today pulling a 2600 lb trailer. Seems fine