still running rough after lim gasket change

[trf_ssei]

i was getting p0300 because of my intake gasket leaking, now after all new seals and gaskets in the top end its better but the engine is still not right. you can feel a vibration from the engine at idel and wot but not when crusing. any suggestions?

[1fatcat]

Tune up? How old are the plugs, wires, fuel and air filters?

[trf_ssei]

all new. vac lines check to be good the only thing i have left that i can think of is the icm is there a way to test it.

[SSEi95]

Do you hear any whistling noise? When I did the gaskets on my sisters 3.4 a couple years ago I found that some of the bolts were still slightly loose, even after using torque specs. It had similar symptoms as you described. Probably not it, but worth checking at least.

[1fatcat]

Try some injector cleaner?

[trf_ssei]

no whistle just rough. another thing i noticed a while ago is: when i disconnect the FPR it seemed to smooth out the idle. haven't tested that driving it yet, thought i would ask if that would be a bad thing first.

could i safely disconect the fpr(plugging the vac line of course) to test it while driving?

[trf_ssei]

Try some injector cleaner?

put injector cleaner in last night and havent noticed a difference yet. also have run it through on separate occasions to no avail.

[1fatcat]

Try using a long screwdriver as a stethescope and listen to the clicking of all 6 injectors at idle, do they sound the same?

Also, check your fuel pressure and clean the MAF if you haven't already.

[rharper]

i would also second checking injectors and coils

[trf_ssei]

all coils are new and injectors were all ohmed and test to be the same. as for the sound they all sound the same smooth and steady.

more info: worse when engine warm.

[rharper]

try unhooking battery for 15-20 min to reset codes and see what codes come up again

[myfirstbonnie]

Check real good for vacuum leaks. Take a can of carb leaner and spray around all the hoses and the LIM and see if the idle changes.

[trf_ssei]

tried carb cleaner seems to run the same. im wondering if the egr is the culprit since it only does it when warm. a buddy has a known good egr and icm im going to try, and ill let you know how it works. another thing that leads me to think egr is i have no power unless at full throtle and even then its not what it used to be. any suggestions or comments?

[trf_ssei]

new info(this is just ongoing). today i gave it a bout half throttle and could smell roten eggs. cat bad? also had a huge lack of power. is it possible that coolant leaked through the engine into the exhaust and somewhat plugged the cat. test ing egr and icm today.

[trf_ssei]

egr and icm replaced and it is better but not perfect and it surges at wot.

[LeSabre in Buffalo]

Plugged cat? Don't they smell like rotten eggs when they're plugged up? Also would explain the lack of power through too much backpressure.

[trf_ssei]

thats what i was thinkin but what about the surging.

[tpulliam79]

I would think the cat is suspect, crawl under there when its not hot and bang on the cat to see if anything inside rattles.

[1fatcat]

Did your engine ever hydro-lock before the gasket change?

[trf_ssei]

no never hydro locked.