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View Full Version : The 03 is up and running!



azgolfrat
03-04-2022, 02:33 PM
Hey Guys,
Well, after ~ 2yrs of learning & effort, the 03 MM is up and running. Rebuilt engine, rebuilt tranny, suspension, headers, cat back exhaust, brakes, etc, etc.
It is running good mostly. Almost done tuning with Marty and Jeff...we had to schedule one last session next week due to some minor problems with the SC air pipes (uh... one fell off under boost). I'd like to thank everyone who has helped me along the way, in particular JustBob and Blazen. JB and Blazen were about as patient and helpful as they possible could have been. Also, Chris at ADTR was all in from the start till the finish, helping me through the install and other issues. If anyone is considering doing business with Chris, please accept my 100% and unconditional recommendation. Marty and Jeff at the speed shop have also been very very very patient and helpful. They seem to me to be THE experts.

But, what would a post be without a problem to ask about? :-)
The speedometer is acting funny. It moves up and down in increments rather than smoothly. It is not jumpy back and forth, but seemingly gets stuck on its way up and down, frequently not reading the correct speed until it gets "unstuck". This concerns me as I understand the PCM controls transmission shifting with the signal that eventually gets to the speedometer, and it does seem that the car shifts at strange times, especially off the line. So maybe the OSS sensor is bad?

I found what I think is the OSS pid (LiveLink and the X4) and monitored it during a drive around the block. The plot of the output sensor vs time rises and falls smoothly - not like the speedometer.

I could yank out the sensor and make sure it is the right one (the 03 and 04 are different per 2003 Mercury Marauder 4R70W Output Speed Sensor - Erratic Speedometer - YouTube (https://www.youtube.com/watch?v=HeCAG8o9lQ4) ,
but before I make a mess doing that I was wondering if anyone has thoughts on what might be causing the speedometer bad behavior.

There is a post from 2020 (Rebuilt 4R70W ... Output Shaft Speed Sensor Issue? (mercurymarauder.net) (https://www.mercurymarauder.net/forums/showthread.php?108820-Rebuilt-4R70W-Output-Shaft-Speed-Sensor-Issue)) that sorta looks like the same problem, but sorta not.

Thanks
-KK

justbob
03-04-2022, 04:45 PM
Well congrats bud! I knew you’d get it going soon enough. If you have other means of vehicles like most of us then no sense in rushing things. I didn’t ever want to see a blow off on mine (26#s boost) so I welded on V band clamps to everything including a removable brace from the throttle body to the pipe and welded the engine mounts solid. I also super glued and zip tie all vacuum lines until the day I would finally convert all over to AN fittings although that day never came before I sold her…

No answer on the speedo except if the values are reading smooth like you say then my guess would be the speedo itself but once again that is a guess. When I did the manual swap mine read exactly double the speed on the way to get my tune and it was smooth albeit being pegged at 140 all the way to the tuners LOL. But that was just a simple calibration tweak.


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Prospect62
03-05-2022, 12:31 PM
Interesting, the way you describe the speedo issue sounds just like how the tachometer's frequently act up (sticky needle).

There's people who fix those tachs, they must know the answer as to why the needle "sticks". I'll bet the speedo is having the same issue?