M60 rough idle

[632 Regal]

reset cures most everything til winter where i know i should have fixed the gaskets the prior season

Do the Shogun Reset?

http://www.bimmernut.com/forum/showt...t=shogun+reset

[nearle]

OK, I've replaced the intake manifold gaskets including the PCV plate, PCV gasket, and throttle body gasket. I also cleaned the fuel injectors and replaced the spark plugs.

I still have the rough idle. Also, when I blip the throttle the revs hover around 2k and take 3-4 seconds to return to idle speed.

The next things I am thinking about checking are: catalytic converters, ignition coils, and O2 sensors...

[nearle]

Diagnosing Catalytic Converter functioning (Please Help):

I crawled under the car to poke around. Tapped the cats with my finger. One has a dampened sound while the other has a resonating ping. Hmmm.

Idled the car for a few minutes then went underneith to check the temps at the cats. Nothing too hot (225 F at inlets), but then the car had not been running for that long. Both cats seemed to have roughly the same temperatures at the inlets and outlets. The temperature difference from inlet to outlet was on the order of 100 degrees F. Seems normal right?

I just hooked up a vacuum gage to the intake. It was reading steady around 14-15 in HG (seems low). When I reved the engine the vacuum increased to around 20 in and held. I read somewhere that it was supposed to return to idle levels. Can someone knowledgeable in this area help me?

[jofusfarr]

Use carb cleaner to spray around the various connections at throttle body - one will go to the brake booster, the other to the charcoal canister. Spray there too. Listen for idle changes.

Once vacuum leaks are ruled out, check fuel pressure.

Does the car suffer from any hesitation on acceleration or perceived lack of power?

[MBXB]

Do the Shogun Reset?

http://www.bimmernut.com/forum/showt...t=shogun+reset

[Rusty Bavaria]

If it's a late production 540 it will have the air pump, smog control stuff on it. Make sure that your air pump valve isn't leaking exhaust into your intake...a nice simple two minute fix that took 3 months and $$ to figure out on my late production 530.

I didn't replace the failed valve just plugged the hose to the intake, well Ok I didn't the mechanic who figured it out did after I almost drove the car off a cliff in frustration.

Jim

[nearle]

It turns out that there is still a leak at the intake, with all new gaskets. One is on the driver's side (left) and one at the PCV plate. I sealed the **** out of the new PCV. Any suggestions?

Is it possible that there is a leak at the oil pipe connections under the manifold? That is the only part that I had trouble with at installation. I have heard people say to push the pipe aft with a flathead. I did not do this.