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  View original topic: rebuilt engine, turns over very slowly
VWinTHEblood Sun Sep 20, 2009 5:16 pm

I recently finished my engine rebuild on my 1970 deluxe, 1600 single port. When I try to fire it up it turns over really slowly. I have a new battery and starter and I cleaned all the corrosion off the connections to the starter and battery. I can't seem to get the engine to turn over fast enough even when it's connected to a running vehicle for a jump start. I noticed that the main transmission ground strap is broken in half, could this be causing the problem? The only other thing I think could be the problem is with the wiring from the ignition switch to the starter solenoid. I can't inspect much of the wiring because it runs under the belly pan of the bus. Any thoughts appreciated. Thanks.

Daverham Sun Sep 20, 2009 5:20 pm

How does it feel when you turn it over by hand? Are we talking about awesome compression, misaligned bearings or an electrical/starter problem?

busdaddy Sun Sep 20, 2009 5:24 pm

Fix that ground strap, the clutch cable is not meant to be a ground path.
As stated, how does it feel?

Desertbusman Sun Sep 20, 2009 5:32 pm

VWinTHEblood wrote: I noticed that the main transmission ground strap is broken in half, could this be causing the problem? .

Think about it. The starter requires a lot of juice. So there is the big positive cable from the battery straight to the starter. Where is the big qround cable from the starter back to the battery? It has to be able to complete the circuit. That ground strap that is broken plus all the bolted connectiions between the starter and trans, trans to frame via the ground strap, and then the frame to the battery with the battery ground cable.
If the starter is turning at all now without the trans ground cable the power is going thru all the lessor metal to metal contacts such as clutch and throttle cables, maybe the axle shafts, and wherever else.
Get a new ground strap on the trans.

VWinTHEblood Mon Sep 21, 2009 4:21 pm

The engine turns over perfectly, all the main bearings are seated correctly. Someone told me that a worn starter bushing may be causing the problem?

Sawsalesman Mon Sep 21, 2009 4:30 pm

Try fixing the strap first.

TomWesty Mon Sep 21, 2009 4:44 pm

All that stuff probably worked okay when you had an engine with weak compression and loose bearings. Now it needs more current to the starter to turn it over because you have a much tighter engine. The strap completes the path for that current. Replace the strap first.

VWinTHEblood Mon Sep 21, 2009 8:52 pm

Okay thanks everyone, I ordered a new ground strap today. Ill post when I get it installed and see if it was the problem.

iratehippie Tue Sep 22, 2009 9:12 am

If you have some good jumper cables you could try and use them as grounding wire, trans. to frame, see if that makes a difference.

a-marshal Tue Sep 22, 2009 11:09 am

or use the jumper cable from the negative pole of the battery direct to the tranny case..

VWinTHEblood Tue Sep 29, 2009 1:57 pm

I fixed the ground strap which corrected the slow starter motor so I was then able to start the rebuilt engine for the first time. I am now trying to work out some kinks in the fuel system to get the engine to run properly at idle. Thanks for everyone's help.

aeromech Tue Sep 29, 2009 2:23 pm

another samba success story



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