http://www.harborfreight.com/digital-photo-sensor-tachometer-66632.html

I thought the HF photo tach was too much$. Got one on Ebay for $12 shipped! Looks a little different than the HF but has the same specs. It's a very useful tool to have.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

What do you use it for?!

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1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

That's kinda cool...

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[/SIGPIC]~cirrusman

1983 Mercedes Benz 300SD - Wife calls him "Chitty Chitty Bang Bang"
[SIGPIC]




1983 Toyota Tercel (Tommy, The little Toyota that could)
1965 Ford F100 (Grandma Ford)
2005 Toyota Sienna (Elsa, Wife's ride)


Gone:
1988 Toyota Pickup
2004 Subaru Outback

1987 Cadillac Fleetwood Brougham
1986 Volvo 740 GL Station Wagon - Piece of junk.
1981 Volvo 242 DL 2 Door - Hated to see it go. R.I.P.
1987 Pontiac Fiero GT

measure rpm

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

There are those of us with early cars that do not have tachometers. This would be great for setting idle speed.

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"Life is tough...it's even tougher if you're stupid." John Wayne


Dave
Pawleys Island, SC

'79 300CD

It would be great for a car with a tachometer too. I imagine it's much more accurate the the dasboard display.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Too bad there doesn't seem to be a way to use this as a primary sensor & hook it up to our existing tachs. That would eliminate a lot of frustration...

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1987 300DT
2002 Ford F-250 7.3 Crew Cab Short Bed

There are modern alternatives to existing tach amps - for example for a OM617:-

http://mbelectronicupgrades.com/Tachometer_Amp.html

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

That alone is not enough hardware to retrofit a OM617 without a tach.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

That is correct! It does not give a real time display. You have to go into memory after taking the reading to see what was measured.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Hmmmm this is cool. I don't have a tach. Would be great to know my idle...

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1984 300td euro turbo

You can use the alternator as a tach signal source...

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42