getting a high pressure pump rebuilt, what exactly is done?

So far I have read many who were advised to send the high pressure pump to be rebuilt when it was found defective. However, I have also read that many just replaced the 4 screens in the pump first and found that resolved their problem and fixed their performance issues. So this has me asking the question of what does a pump rebuild involve if just replacing the 4 screens is fixing the problem and saving lots of $$$$. Is there more to the rebuild than just replacing or cleaning the 4 screens?

Just wondering as I am starting to believe I am finding myself having to possibly send mine in for rebuild if the results from the water test indicate tomorrow. I have even compression, and good spark. But, the engine is idling extremely rough, does not seem to be running on all 6 cylinders in gear, when shifting from neutral to forward there is no clunk like usual, now it is very smooth like not engaging the other 2 cylinders, and it is smoking bad and fouled my plugs. All filters just replaced, O2 sensor is reading 0.12 at idle in gear at operating temps. I will not get up on plane, like lack of power. It has been idling rough for a little while now and I have noticed the smoking increased somewhat in the past couple weeks. Does this sound like a high pressure pump issue or something else possibly?

I'm getting frustrated because I stuck about $1200 into this motor on filters etc and the trim/tilt just recently in the past month and a half, and now this. Worst of all, my classic is Oct 6-8....bad timing. http://www.bassboatcentral.com/smileys/crying.gif

First, you need to eliminate all the possible problems before doing any maintenance to high pressure pump. I believe yours is a 2.6L since you mentioned the O2 sensor. If the O2 sensor was never pulled out for cleaning you need to do that first. Then check the low pressure pumps (lift pumps that supply fuel to VST). Only after those two things and all the other fuel filters are replaced I would start looking into the high pressure pump. I know for sure that the 3.3L hpdi has 4 screens but the 2.6L I believe only has two. They are not very difficult to replace. Only one plate to remove and change out the screens. At this time I would also have all the injectors cleaned and flow tested. They also have these little screens. I highly recommend Brucato for this service. Brucato can also, if necessary, mechanically adjust flooding injectors. This adjustment is extra but well worth it if you have flooding injectors as this is a common problem on many injectors, not only on hpdis. Brucato will also supply the screens for the high pressure pump if you use their service for injectors. Hope this helps…good luck!

Thanks Rich. The )2 sensor was just recently checked out and cleaned about a month ago. The lift pumps were rebuilt last year. I will have to ask the mechanic if he checked those. I asked him about those and he doesn't believe those are the problem. But, I will ask him to check them anyways. I was planning on having the injectors cleaned and flow tested after my classic in a week, but now I have this going on so I have to do something before then. If the lift pumps check out and everything else, the only thing left is the high pressure pump which is being water tested today. If it fails, should I just replace those screens first before actually sending it to get rebuilt? How do I know or the mechanic if it needs rebuild rather than just screens? Thanks again!

It’s a process of elimination. When hooked up to YDS the pressure will be low or fluctuate, an indication of high pressure pump problem. Change screens first before having to remove the pump for service or unnecessary replacement which can be very expensive. I have yet to see, hear or read anywhere that these pumps fail but it is possible.



Modified by Rich Z at 9:49 PM 9/23/2011

Got the boat back today. Water test showed the high pressure pump being at 712 psi at highest in gear idling and at 5000 rpms (highest rpms reached due to mechanic driving boat having to shut it down due to chinewalking) 640 psi. With that being said, I spoke to Matt from HT about my situation prior to finding out about the water test results and he was a great help. After explaining to him all my symptoms, he did not feel it was the high pressure pump that was bad, and he was correct. The mechanics found that the problem was actually in the shift switch. When going into gear, the switch was not being tripped to engage the other 2 cylinders and after playing with the switch on the water, the mechanic was able to get the switch to operate properly. When I arrived the service place, the mechanic was taking the switch off the motor and I saw exactly why that was happening. The contact lever that pushed the rubber button in when shifting into gear was not making full contact. The mechanic cleaned it, regreased the track so it was smooth, and bent the contact lever slightly to make more contact with the button. He also replaced my spark plugs, cleaned all the grounds on my spark coils, tightened everything that was loose, and also raised the idle rpms to 750 rpms where it should be in gear. I took it out after and ran it and it was definitely a different animal. It idled much smoother and quieter, better and smoother throttle response, and it ran consistently at 70 gps at 5750 rpms. Been a long time since it ran this smooth and 70 consistently. I put it in gear and out several times and so far no issues. I will be ordering another switch just in case, and also will be getting some HPP screens too and replace.