Finished changing both valve cover gaskets,

[Bo525i]

used http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/auto_Permatex_Ultra_Copper_Maximum_Temperature_RTV _Silicone_Gasket_Maker.htm to seal it up well and for ease of reinstallment of the covers, got rid of 98% of the hesitation/stutters I had @ cruising speeds due to soiled plugs and sockets!

Now my question is: I´ve changed plugs, checked the sockets, changed fuel filter and pump/sender unit, no apparent holes in any hoses and I´ve cleaned the ICV for good measure.. Only thing I haven´t done yet is a reset of the computer!
I still have a very slight stutter/hesitation occasionally (much much better compared to before but still) when cruising, so where do I look now?

[bubba966]

Which car has the stutter? If I had to guess I'd guess the 530 as you mention "both valve cover gaskets".

But would help to know if we're talking about an M50 or an M60...

[Bo525i]

True, the M60 with 2 valve covers! ;)

[bubba966]

How are your coil boots?

I had a slight misfire/stutter at 2.5K+ RPM. While the coil boots measured to still be in spec, the rubber was slightly deteriorated due to heat. Changed the coil boots as I'm fairly sure they were the originals and that misfire/stutter is now completely gone. It runs really smooth now from 2k-7k RPM.

[Bo525i]

Hmmm, they seemed to be in perfect working order, no apparent deterioration.. But I might try changing them anyways!

[632 Regal]

Hmmm, they seemed to be in perfect working order, no apparent deterioration.. But I might try changing them anyways!
Make sure you get matching boots :) If you have bremi coils go with bremi boots, resistances are different.

[Bo525i]

Bremi it is! ;)

[Bo525i]

Finally got around to changing all the coil boots, the difference is like night and day!

Better mileage, all the little annoying stutters are gone, throttle response has improved and the acceleration is smoooooth now!

The old ones seemed ok, no cracks but actually didn´t sit tight. When pulling them there was no resistance at all like with the new ones which go in and out with a satisfying tight feeling!

[bubba966]

Good to hear the new boots fixed it.

My old ones looked ok for the most part. Even measured fine resistance-wise. But putting new ones in was definitely an improvement.

Kinda makes it hard to figure out if your boots are bad or not. Haven't found any info on checking them out other than swapping them with new ones.

[Tiger]

Don't bother trying to measure old boots... One thing I know for sure between old and new is that when you measure the resistance... old boot will measure out fine and sonstantly as long you keep the probes on it.

The new boots does not allow constant measuring... it will display measurement for 1 second or so and then stop back to disconnected as long you keep the probes on it. To get the reading again, you have to release one probe and touch it again. Sort of like pulse technology... allowing one pulse at a time.

[CharlesAFerg]

used http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/auto_Permatex_Ultra_Copper_Maximum_Temperature_RTV _Silicone_Gasket_Maker.htm to seal it up well and for ease of reinstallment of the covers, got rid of 98% of the hesitation/stutters I had @ cruising speeds due to soiled plugs and sockets!

Now my question is: I´ve changed plugs, checked the sockets, changed fuel filter and pump/sender unit, no apparent holes in any hoses and I´ve cleaned the ICV for good measure.. Only thing I haven´t done yet is a reset of the computer!
I still have a very slight stutter/hesitation occasionally (much much better compared to before but still) when cruising, so where do I look now?

Reminds me, I've got to rebuild my M20 here pretty soon. I can't imagine how nice it will run. I'm almost at 200k, and there are a few issues I'd like to contend with. I wonder what kind of upgrades I should perform while I've got it in surgery...