Rpm needle wiggles very fast before starting
- Thread starter Cwildred
- Start date
Cwildred
Member
Anybody have an idea?
oilhammer
Certified Volkswagen Nut & Vendor
How long is it cranking before it starts? My '99.5 doesn't do that, but it is in such good health it starts very quickly.
Cwildred
Member
It takes a while to crank But I think I need a new starter. I just bought it 3 months ago. It's at 307k miles. Runs really strong after it starts.
gmenounos
Vendor
- Joined
- Jun 26, 2003
- Location
- Watertown, MA, USA
- TDI
- '99.5 Golf GLS, '01 Jetta GLX Wagon (TDI conversion)
99.5's also have a hot start issue in the ECU that can be fixed via a tune: https://forums.tdiclub.com/index.php?threads/99-5-starting-hard.365127/
Cwildred
Member
I know about that one. I use it only for commuting so I drive 50 miles to work then it sits for 8hrs then 50 miles home. I have another car for errands on the weekend.
wonneber
Top Post Dawg
- Joined
- Oct 12, 2011
- Location
- Monroe, NY, USA
- TDI
- 2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Measure the battery voltage while starting the engine.
If it drops below 9.6 it could be below the voltage needed for the ECU.
How old is the battery and is it the correct one for the TDI? (not a gas engine battery)
If it drops below 9.6 it could be below the voltage needed for the ECU.
How old is the battery and is it the correct one for the TDI? (not a gas engine battery)
Randomhomelesstdibeetlegu
Veteran Member
You have AC noise on your crank signal wire. If I remember right from my issues the ECU passes crank signal to the cluster iirc.
My tach would do a little bump key on then register crank signal and start at times then not.
My issue was swollen ECU connector seals pushing back enough to make the pin connection garbage.
Removed them had full signal on tach. Signal showed up at connector but not tach. New junkyard seals and it hasn't done it since.
My tach would do a little bump key on then register crank signal and start at times then not.
My issue was swollen ECU connector seals pushing back enough to make the pin connection garbage.
Removed them had full signal on tach. Signal showed up at connector but not tach. New junkyard seals and it hasn't done it since.
Cwildred
Member
Battery is new only 3 months old. Yes it is a tdi.
Sorry im new to wrenching, how can I diagnose this issue? Do I need to get at the ecu under the windshield and look at the connections? I also have a long crank issue I replaced fuel filter, and sending unit and thermo T. So I'm confident it's not fuel related. I'm starting to think it's the starter or something to do with this electrical gremlin in my tach? Please advise.
Randomhomelesstdibeetlegu
Veteran Member
Tach show starting RPM or not?
Cwildred
Member
Like when I'm turning it over? Before it actually starts? Did notice that if I leave the key in the on position for a few seconds it will stop wiggling.
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Randomhomelesstdibeetlegu
Veteran Member
Yes.
Cwildred
Member
When starting the tach goes up to the first line so about 200 rpm I think
compu_85
Gadget Guy
This could just be the gears in the tach getting worn out, and the cluster is struggling to home the servo.
-J
-J
Cwildred
Member
Does that explain the wiggle though? I do have vcds what should the cranking rpm be at? Around 300 I think right?
Randomhomelesstdibeetlegu
Veteran Member
I believe so.
When I had more wiring issues than I had the tach would do that. Later on now it does not.