Hey so I've already had my IP go a few years ago so when it started to act up on start up, excessive cranking when warm I wasn't surprised. Went on for a while then wouldn't start, I was hoping the fuel was low in the filter alas it took pouring water on the thermostat to get it to fire right up and I knew it was time for a rebuild.

I already got a working core off craigslist for $80, god I love that site, and a rebuild kit for like $50, and god do I love my part stores account with BD Diesel. She's stripped down, cleaned and I'm in the process of rebuilding it.

My questions this time are what causes them to fail? This one lasted 2 years and was rebuild by a reputable shop, last time it lasted like 4 years in my ownership and some time before but I was WAY down on power before it finally gave up the goat. But this time she still runs like a bat out of hell. Okay a brick shaped bat on 35's with, to quote my uncle, "highway gears".

She isn't down on power at all, it's the fuel economy that is murdering me. I've been using fuelly to keep track of my fill-ups and economy and I've been averaging between 17-19 unloaded with a mix of city highway. Now I'm lucky to get double digits. Weirder still I got close to 14 when towing my wife's escape around town and on the freeway to my shop and the rental trailer back, than I do driving around empty. Costing me about $10-15 in fuel a day commuting. So it got depressing to monitor economy and I stopped.

Is there any insight that people have on these pumps?

 

Timing.
Also, check, are you smoking more than usual? Maby a fail(ed|ing) injector or two.

 

Injectors are likely fine, replaced them recently. Only get a like 2 second puff on startup and only when I lay on it hard do I get another puff.

 

I agree with Macrobb, could simply be that your timing needs to be adjusted. New injectors with a used IP will tend to cause whatever wear happens in the IP to accelerate a bit, tolerances loosen and throws off the timing.
It's cheap to fix! Way easier than an IP rebuild. : )

-Joshua

 

Injectors were done like three months before the IP was done.
If what you suggest is the case I have some questions as I've run this IDI timed properly and not timed properly and it still performs great with the exceptions of starting and economy.
First of all without some outside stimulation how would the timing change? (sure with time you'll see it to go slightly off but I can't see it being substantial in just two years), and secondly how would it affect the thermostat causing failed starts? While the thermostat is in the upper chamber and it does receive a good amount of heat I can't see how any adjustments made to the timing below would have an inherent effect on it, unless it is going to suddenly make a drastically reduced amount of heat. It isn't like it is dumping fuel early and causing a large amount of unburnt fuel to escape, if that was the case I'd just retard it. There isn't any real stumble of it getting fuel late either, nor is there any (not a misfire, but I can't remember the right word for it) which would signify air in the lines.


And $80 for a working core and $50 for a rebuild kit is pretty good, as the best deal I could find last time was $675 for a rebuilt IP.

 

post pics of the rebuild! i hear it's next to impossible to do in the avg garage due to the extreme tolerances

 

Well I'll admit it isn't something I would have attempted a year ago as I would describe myself as more shade tree than anything else. But I got a job working for a shop under a guy who restores and builds custom Porsche's, Bentley's, Lotus's, etc. He basically told me to get the rebuild kit and he would assist if needed. So once I figure it out and perfect it (may take a rebuild kit or two to get it down, till then I'll just pick up cheap rebuild IP's from wreckers or CL to practice on) he will have me start offering them out of the shop as something that can be done there, likely pick up a timing meter as well.

I'll take a photo or two for this one, but until I'm certain of how to do it and wont cause engines to grenade, I won't be posting any instructional info.
But here is a link to the service manual that I'm keeping open on my phone. It is hosted on my OneDrive, it isn't 'exact' but it is close enough that any questions I have can be figured out based on the likeish pictures.
http://1drv.ms/18ez6gH

Here is a very short lived thread with info on rebuilding them.
DB2 Injection Pump Manual/Parts Illustration? - Diesel Forum - TheDieselStop.com

Most of the links from it work, but I think one doesn't.

 

I like your enthusiasm for rebuilding pumps but I'm sorry to say your way beond what you can do.

Yes you can take a perfectly running pump that leaks like a sieve and re seal it, thats not hard, I've done it, but to actually make a worn out pump work again will require hard parts like metering valves, rotor and head assembly (roughly $6-800 a pop!!!) transfer pump vanes/assemblies, over size servo advance pistions and something to ream the housing over size and to smooth shape, new over size plungers, a flow bend, ect... and if you think a drill bit is your friend in these pumps, walk away now before you sell one to someone and the metering valve gets stuck wide open and causes an acident.

Have fun with your own personal truck and parts, nothing wrong with you wanting to fix your stuff, these pumps are really easy to understand and take apart, but please don't be tring to offer a rebuild pump service, it won't work.

Thats what make a rebuild a rebuild instead of them ebay people that end up into the hall of shame/ ripe off sellers.

Have fun with your stuff and post how your reseal kit goes.

 

Sorry for any confusion that I may have caused I know entirely that it is resealing and does not include boring out to remove worn or damaged parts. I may have said rebuilt in error, as it is a commonly misused term in smaller equipment.
I'm on my phone so I can't really hit on all your points, but ill look at it more in depth when I get home.
Also if you spent an hour talking to the guy that I work with you'd laugh, feel silly and take back what you said, just saying.