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'76 450 Suddenly wont start overnight

Started by bfam4t6, 21 November 2008, 12:43 AM

bfam4t6

So my '76 450 would not start this morning.  It has always been a little difficult to start this car, especially when the engine was already warm.  Also, the car would usually not rev past 3500 RPM...since it was intermittent I assume it was electrical.  I don't know if the previous information will help, but then I tried to start my car this morning it wouldn't do anything.  I know the battery wasn't dead because the lights and radio all worked and I know nothing was left on when I parked it last night.  The car only has 70,900 miles and runs extremely well...until this morning.  What could cause this?

TJ 450

1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

bfam4t6

Nope.  Turning the key doesn't initiate the starter at all....which leads me to believe that this could only be caused by a faulty starter (which I would imagine would die slowly rather than very suddenly) or a small handful of other components. 

koan

#3
Any clicks or clunks from the engine when you try starting?

Try starting in ""N" instead of "P" and try wriggling the gear selector lever when you attempt to start.

You say "difficult to start this car, especially when the engine was already warm", did the engine crank and not fire, or not crank at all like you have now?


koan
Boogity, Boogity, Boogity, Amen!

macatron

Quote from: koan on 21 November 2008, 01:14 PM
Any clicks or clunks from the engine when you try starting?

Try starting in ""N" instead of "P" and try wriggling the gear selector lever when you attempt to start.

You say "difficult to start this car, especially when the engine was already warm", did the engine crank and not fire, or not crank at all like you have now?


koan

Yes, I was going to say if all other electrics initiate but the starter, make sure the shifter is completely in park as koan said.  It happened to mine the other day.

kolin

maybe the engine has totally seized and its not the motor

TJ 450

That's always a possibility, although it's better to keep it simple. I would ensure that the solenoid is getting its current. The first thing to do would be to move the gear shifter back and forth a few times. The starter lockout/PNP switch could be playing up.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500

BAR

Typically this would indicated that the starter is dead, given that the Battery condition is good and that the gearbox is in P or N.  If you're in Australia, call the local Road Service [NRMA RACQ or whatever] if overseas, try the equivalent as they can quickly point out the problems.

As for not going over 3,500 RPM, try replacing the ignition module.  When the capacitor start to fail, they cannot hold sufficient charge to fire the coil and the engine behaves as if you have a rev limiter.

A second hand uinit should be around Aust $ 70 - 80.