Power loss at higher rpm

[RustyCaddy]

Thought i would start a new thread for this.  Had a pump stop from bad fuel, tried another pump but it needs resealing, cleaned and resealed the original pimp that quit. While resealing found that the spill collar was frozen on the plunger.  Cleaned the collar and plunger and it freed back up.

Put the pump back on.  The pump is doing well at low rpms but as rpms go up the power is dropping off. Once i down shift to a lower rpm the power is back up.  This might sound familiar to someone?  What internal part of the pump might cause this? May be the spill collar is no longer moving as it should?

Any advice is really appreciated. Thanks!

[carrizog60]

have you checked the basics?
timing,fuel filter...
could double check that the in and out bolts are in the right place,the throttle lever is in the right place.
 

[RabbitJockey]

yeah i'd be eye balling the throttle.

[RustyCaddy]

Thanks for the suggestions!

The filter was just changed when i ran seafoam through the pump but will change it out again just in case.  Throttle linkage looks good. It is timed to 1.00 mm because it is an old pump.

The truck is driveable as long a i shift a little early.  If the rpms go up, the power drops, and the engine hesitates till i let the pedal back up. Going downhill the power gets really poor, but the funny thing is if i downshift at that point the engine runs smooth at high rpm but again no power.

This reminds me or the reason for the governor mod, isn't there a fueling limit in the unmodified governor at high rpm? This pumps governor has not been modified. Weird

[vanbcguy]

Any Idea what RPM it starts cutting back fuel at?

Sent from my XT1097 using Tapatalk

[RustyCaddy]

Work has had me busy, sorry for the late reply.

Also, as it seems, sorry for my stupid question (in case anyone here doubted i was an idiot the following will correct that).

So i took the pump with the "high rpm" problem off. i had 3 non-working pumps, removed the working units from each and assembled a franken pump.  Surprisingly it worked!

https://www.youtube.com/watch?v=xos2MnVxe-c

But...it had the same high rpm issue. So what would cause fuel to cut-off at high rpm. D'oh!

i had removed a inline heating element for vegetable oil and inserted a low pressure fuel pump to prime the pump 1. There was a clear inline filter down stream which apparently caught a bunch of vegetable oil crust that got knocked loose when the heating element came off.

Replaced the inline filter screen and cleaned things up.  Rev problem gone.

So to recap, made a bad batch of biodiesel, did not test it for soap, added it to the car, froze the spill collar on the plunger shaft, removed pump 1-freed up and cleaned the spill collar-resealed, reinstalled pump 1, loss of power at high rpm, put on resealed franken pump 2, loss of power at high rpm, cleaned inline filter, runs great=>=> i am a big idiot!!!!

[ORCoaster]

In one way it is good to have spare parts and then again it adds variables to the equation when you do.  So trying to figure out a problem at the same time switching out parts is not always a good idea unless you know the part is good and you are trying to find another possible problem.  Like knowing your light bulb is good, it glows on the socket on the right so what is the problem on the left when it no glow?

Glad you got it.  Had you mentioned the fuel setup some of us might have suggested looking for a restriction prior to the pump for a fuel starvation problem. 

[RustyCaddy]

Your right about that.

i kinda of uncrossed two threads about the problem, this one and this one;

http://vwdiesel.net/forum/index.php/topic,36625.0.html

The whole turbo pump episode is best forgotten