Injector Pump Identification

[toddjo]

My '91 6.2 gave up on me a while back... The fuel injector pump locked up tighter than a drum and sheared off the woodruff key in the cam shaft, spun off the gears and dropped the whole works down into the engine... OUCH!
Now I'm trying to get a different fuel Injector pump in the truck, but there seems to be a problem with the model that is in there. My 6.2 has an after market Banks Turbo kit on it, and my local diesel mechanic is telling me that the pump is the wrong one. He says that there is a diffrence in those pumps from a turbo engine vs. a pump from a naturally aspirated engine. How can I tell what pump is SUPPOSED to be in there? With the Banks upgrade, should a different pump been installed? I saw the pump list on the Diesel Page, but the one that I currently have isn't even close to what the list shows that I should be using. I keep hearing that ANY pump of the "J" code type will work OK in my truck. HELP! :confused:

[britannic]

The Banks system used the stock injection pump since it's an aftermarket add on, so your mechanic could just go ahead and replace it with the same model. However, if you're going to spend the money on fixing the engine, why not slap in a DB2-4911 pump and maybe spring for some 6.5LTD injectors to complement it. The pump may need a tweak if the you're using the non-wastegated turbo to clean up any smoke below 2500rpm.

If the timing chain is worn, this may also be the moment to consider dual idler timing gears to replace the chain and cogs - just a thought :D .

[toddjo]

Well, this is the 2nd or 3rd time I've heard this. Is this something that I, as a novice with Inj. pumps, should be doing? Or would it be better for a pro to do the dirty work? I have little experience with pumps. The rest of the engine I can handle blind folded.... I just don't want to invest a $grand$ to end up messing it up.
Thanks for your input! smile.gif

[britannic]

YMMV, but installing an IP is not that difficult for anyone that can remove and install a waterpump for example, just little more long winded and time consuming. I've done it 4 times and have accumulated a variety of tools that make it easier, such as crowsfeet wrenches, magnetic pickups etc., etc.

[toddjo]

I've been in contact with a guy that has rebuilt injector pumps and claims that the bore and piston are changed from 49cc to 56cc. Due to the extra displacement, the HP rating can jump above 200 hp... Does this sound right? :confused: The one that he last had was a db2831 4911/j...

[britannic]

Check this thread out: DB2 Explained... (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=002168)


Originally posted by toddjo:
I've been in contact with a guy that has rebuilt injector pumps and claims that the bore and piston are changed from 49cc to 56cc. Due to the extra displacement, the HP rating can jump above 200 hp... Does this sound right? :confused: The one that he last had was a db2831 4911/j...

[toddjo]

Well, after reading through all that great information, I have a much better grasp on the DB2! Thanks for the info. That's exactly what I needed. I'll let you know how this project comes out. Thanks again for all your help. :D

[JeepSJ]

Sort of along the same lines of ID'ing a pump. Elsewhere on the site I read that early 4911s had a hot start problem and that "later" pumps had improvements. What build dates apply to the early and late pumps? Mine appears to have been mfd in April 1993.

[toddjo]

Hey Britannic,
I've been a little tied up with other projects and am just getting back to the issue with my 6.2. Earlier, you recommended replacing my worn chain and gears with dual idler timing gears. Do you have a good source for purchasing these? After putting the old chain and cogs on, I'm realizing how badly they need to be replaced.

I have not taken the heads off this engine and I'm now having concerns that when everything came apart, (see first posting) that I may have damaged the tops of the pistons and/or valves. I guess I'll have to do a compression check when I get the timing chain replaced.

[britannic]

Did the camshaft timing gear disconnect from the crankshaft chain? If it did and the engine continued spinning down after the catastrophe, you may have bent valves. May be worth R&Ring the heads whilst you're at for peace of mine.

Check out the DP sponsors for dual idler gear suppliers - I bought mine from Kennedy Diesel - www.kennedydiesel.com (http://www.kennedydiesel.com) .

[toddjo]

Ohhh yes.... I was doing about 40 MPH when the whole thing just shut down. The drive gear to the IP and the timing chain gear both came completely off the end of the cam shaft and dropped down into the housing. I'm sure the crank did a few revolutions after the cam stopped turning. :rolleyes: I'm getting a knot in the pit of my stomach just thinking about it. I did take the rocker cover off the drivers side and turned everything by hand and all the rockers/valves moved OK. But the other side has that darn Banks turbo and related hardware. I guess tomorrows project will be pulling the heads, like it or not. Hey thanks for the advise (again)!

[britannic]

Yeah, thoses heads have to come off, be prepared for bent rods & valves and maybe some piston damage :( .

[toddjo]

Well Britannic, it's been a while since I chatted with you on this subject, so I thought I'd bring you up to speed. I tore down the engine that died on me and found more that I had bargained for. I found bent push rods, bent valves, bent connecting rods, bent cam and a badly fractured lifter housing. So the whole thing was a bust. I bought a remanufactured engine and have been putting the components on it and getting it ready to drop in. In addition to the original engine being shelled out, my Banks turbo looks to be in bad shape, too. So, some more money and time and I should be back in business, soon. Thanks again for all your input. This has been a very valuable experience, to say the least.