MM Problems

[jabird56]

My MM is currently staying with the LM dealer, seems I have had some times recently where it's hard starting and runs rough at idle. Dropped it off this morning, and they couldn't get it to replicate and nothing showing on the computer so they're keeping it overnight and will try again tomorrow. It's 40 miles shy of 36,000 miles and I have been using 93 octane. I am not one who "stomps" on it. Any ideas/opinions?

:confused:

[Blackened300a]

I have noticed something similar, At times In the morning the car would start on the 2nd turn and the RPM's would jump up to 1000 when it fires. Once and a while, I would crank it and when it Fires, The RPMs would fall flat and the idle would stumble a bit. I havent noticed it to affect the drivability of the car. However, Certain Gas Stations I have filled up from have caused it to do it more often. I would assume bad Gas is the problem.

[CRUZTAKER]

'03 300A....ehh...

Have you recieved the software update 3U7A-12A650-AMA?

It's early 300A build specific for cold starts.

Just a note however, if CAI of any type has been installed it just fusses everything up.

[RF Overlord]

jabird...I notice in your sig you have a K&N air filter listed...is this one of the drop-in panel filters? If so, those have been implicated many times in fouling the MAF...the oil from the filter gets pulled onto the hot-wire sensor and causes incorrect air mass readings to be sent to the PCM...the wires can be cleaned VERY CAREFULLY AND GENTLY with a Q-Tip soaked in electrical contact cleaner (NOT carb cleaner!)...give that a try...

[SergntMac]

I am not one who "stomps" on it. Any ideas/opinions? Yeah...Stomp on it once in a while. Do more "on ramp" romps and clean the bit*h out.

Carbon build-up is as bad as detonation, in fact, they work hand in hand. When carbon builds up in the compression chamber, it increases your compression unevenly, and it gets hot all on it's own and creates "hot spots" which ignite the fuel charge spontaneously, much like a diesel engine. Carbon build-up doesn't burn evenly, and the result can be detonation, or, pre-ignition. You don't want either, trust me.

You own a heavy breathing high performance engine, exercise the lungs more. Like any "shallow breather" (most common among senior citizens), you need to cough it out once in a while, spit up a hair ball and breath deeper. Your MM will drive better.

It never ceases to amaze me how we seem to have two camps here. One camp routinely lets their "pony" stretch it's legs, the other does not. Which camp spends more time at the dealership with complaints like this?

Don't mean to be down on you, Dude, I could be wrong about it all. I stretch my MM legs as often as I can, and I don't have these problems, so, it's just my .02C on it, K? Hope this helps, if it doesn't fit your MM program, nevermind...

[Smokie]

My MM is currently staying with the LM dealer, seems I have had some times recently where it's hard starting and runs rough at idle. Dropped it off this morning, and they couldn't get it to replicate and nothing showing on the computer so they're keeping it overnight and will try again tomorrow. It's 40 miles shy of 36,000 miles and I have been using 93 octane. I am not one who "stomps" on it. Any ideas/opinions?

:confused:Change the plugs....and stomp on it....the car loves it.:D

[jabird56]

Everybody thanks for the comments, Sarg...your a trip :burnout:. I don't stomp on it as much as some others, I will stomp on it once in a while. I did stomp on it to clear the carbon; however, that didn't clear the problem. I will check into the software upgrade and the MAF sensor.


Yeah...Stomp on it once in a while. Do more "on ramp" romps and clean the bit*h out.

Carbon build-up is as bad as detonation, in fact, they work hand in hand. When carbon builds up in the compression chamber, it increases your compression unevenly, and it gets hot all on it's own and creates "hot spots" which ignite the fuel charge spontaneously, much like a diesel engine. Carbon build-up doesn't burn evenly, and the result can be detonation, or, pre-ignition. You don't want either, trust me.

You own a heavy breathing high performance engine, exercise the lungs more. Like any "shallow breather" (most common among senior citizens), you need to cough it out once in a while, spit up a hair ball and breath deeper. Your MM will drive better.

It never ceases to amaze me how we seem to have two camps here. One camp routinely lets their "pony" stretch it's legs, the other does not. Which camp spends more time at the dealership with complaints like this?

Don't mean to be down on you, Dude, I could be wrong about it all. I stretch my MM legs as often as I can, and I don't have these problems, so, it's just my .02C on it, K? Hope this helps, if it doesn't fit your MM program, nevermind...

[glassman99]

Marauder....not one who "stomps on it"...whaaaats up? They are made (fun) to run.

[BigCars4Ever]

My MM is currently staying with the LM dealer, seems I have had some times recently where it's hard starting and runs rough at idle. Dropped it off this morning, and they couldn't get it to replicate and nothing showing on the computer so they're keeping it overnight and will try again tomorrow. It's 40 miles shy of 36,000 miles and I have been using 93 octane. I am not one who "stomps" on it. Any ideas/opinions?

:confused:Not an expert but in a crown vic 4.6 that would indicate a bad cam shaft position sensor. Poor idle and hard starting but it also usually throws a light.

[MENINBLK]

jabird...I notice in your sig you have a K&N air filter listed...is this one of the drop-in panel filters? If so, those have been implicated many times in fouling the MAF...the oil from the filter gets pulled onto the hot-wire sensor and causes incorrect air mass readings to be sent to the PCM...the wires can be cleaned VERY CAREFULLY AND GENTLY with a Q-Tip soaked in electrical contact cleaner (NOT carb cleaner!)...give that a try...

NO Q-TIPS !!!

Just spray and let air dry.
Use Radio Shack 64-4345 Electronics Cleaner.
Spray it on generously and let it AIR DRY...

[ckadiddle]

Heck, I thought it was only therapeutic for ME to take it out for a little "flight" once in a while. Now I know it's good for the car too. :)

[Wires]

Yeah...Stomp on it once in a while. Do more "on ramp" romps and clean the bit*h out.

Carbon build-up is as bad as detonation, in fact, they work hand in hand. When carbon builds up in the compression chamber, it increases your compression unevenly, and it gets hot all on it's own and creates "hot spots" which ignite the fuel charge spontaneously, much like a diesel engine. Carbon build-up doesn't burn evenly, and the result can be detonation, or, pre-ignition. You don't want either, trust me.


I try to tell my wife that - our 1998 GMC truck with a 350 engine is carboned up because she won't "open her up" every now and then.

The cars I drive don't seem to have that problem.......

I asked a dealer what it would cost to remove the heads and scrape the carbon - it was as much as a new long block.

[UNKNOWN]

check out this thread, maybe it will help. sometimes the problem is more simple than expected.

http://www.mercurymarauder.net/forums/showthread.php?t=19767

good luck anyway and let us know what happens.

[jabird56]

Well, I got my MM back. The dealer checked everything out and it just won't replicate the hard start and rough idle for them. They checked the software update as mentioned above, they agreed the MAF sensor would have set the check engine light off (but they cleaned it anyway), they ran diagnostics in the garage and with a remote system they took it for some runs, they started it numerous times throughout the day, plugs were good, ...nothing popped up. My service writer told me the issue is logged in the system, if/when it happens again drive it directly into the service lane and he would get somebody on it right then. It's one of those bugs, I can't fault them they tried everything they could think of and I passed all the comments on from this thread. It's just this gremlin just decided to hide from them, and it didn't do it when I started it up to leave or the drive home. So,..."news at 11".