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Engine Specific Info and Questions => IDI Engine => Topic started by: bluemotion on April 08, 2009, 02:16:37 pm

Title: Newly Rebuilt Injector Pump is Unusually Loud
Post by: bluemotion on April 08, 2009, 02:16:37 pm

I just installed a newly rebuilt 85 Golf NA injector pump from a local shop and the engine is unusually loud.  At 1mm of timing, the diesel knock is very loud.  I can retard the timing to quiet the engine down, but I'm not sure if that is the best idea.  What do you guys think?  I don't understand how a 1mm timed pump can cause an engine to be louder or more quiet after the timing of the pump was checked.

Title: Newly Rebuilt Injector Pump is Unusually Loud
Post by: rallydiesel on April 08, 2009, 02:40:10 pm

Was this from a Bosch shop? If they aren't very good, they may have replaced stuff that will affect timing adjustment (plunger spacer too thick, timing plug too long, different exit banjo with too small a hole, etc....).

Title: Newly Rebuilt Injector Pump is Unusually Loud
Post by: bluemotion on April 08, 2009, 02:46:49 pm

The strange thing is that the pump is loud at idle and low RPM's.  At idle, there shouldn't be a timing curve.

Title: Newly Rebuilt Injector Pump is Unusually Loud
Post by: burn_your_money on April 08, 2009, 05:10:37 pm

A fresh pump should be ok timed at 0.90-0.95mm How far down do you have to retard it to get it quiet?