[Vwdiesel] No start

[Roger Brown]

MWoodland at Dentsply.com wrote:
> Washed the engine yesterday ('91 1.6 NA) and detailed the engine /
> compartment, including repeated applications of aluminum mag cleaner.. a
> mild oxalic acid solution.
> It pulled all the rust, and I sealed it all with a clear spray that
> converted any remaining rust to a black primer.
> I fired it up after the acid washing / neutralizing to dry the engine
> before spraying, and it started fine.
> 
> This morning, I cycled the GPs and it popped once and didn't 'catch'.
> Cycled again and no start.
> 
> 1. The fuel stop valve is getting 12v, and I can hear it firing,
> 2. GPs are getting 9 VDC (?)
> Checked connections / pulled and cleaned connections to GP fuse, and still
> 9 vdc at GP buss (?)
> Battery shows 12vdc, and starter spins fine.
> 
> I had to bail on the diagnostics to get to work, so grabbed my wife's car.
> Where next?
> GP relay? I would think the GPs should be getting 12v.
> Any BTDTs?
> 
> Best regards,
> Mark

On my '82, I get about 11.2 volts at the GP bus, with about 12.0 volts on the battery 
(under load). Battery w/o the plugs on is 12.6 volts before hitting the plugs. Not sure 
how hot the plugs will get at 9 volts, but power output is exponentially related to the 
voltage across the plugs.

Check the voltage (and drop) across the fusible link (if present) and if all that is OK, 
then might have a look inside the GP relay at the contacts.

-- 

   Roger