Truck stumbles and generally runs like snot. Gray smoke. Funky throttle response and surging.

Unplugging OS clears up most problems. No gray smoke, runs smooth, does not miss. Throttle still slightly funky between 600 and 1200 rpm.

Installed reman'd long block 200 miles ago. Ran great for 200 miles.

Not sure if the os filter harness is still there or not. If it is there, I will take it out of the loop and retry.

If it is not there (pretty sure it's not), which direction should I go. Problem happened about 100 miles after filling the tank. I'm wondering if the sensor is seeing something it does not like? No codes present. Perhaps look for air in the line? OS went south or IP tanking? 5521 pump with about 60k on it. Bench tested at a Stanadyne shop while I had it off for the motor r & r. Bench tested good.

Lewis

OS filter harness is M.I.A.

what do you mean the OS filter harness is mia. You said in your first post that you disconnected it.

There is an electronic filter that plugs in between the OS and the wiring. It's not there as far as I can tell. Looks like this...
http://www.ssdieselsupply.com/images/products/fullsize/62--20041226175457.jpg
The left side plugs into OS, the right side plugs into the wiring harness. Someone has already removed this from my truck as far as I can tell (I am 3rd owner, at least).

I pulled the plug off the top of the pump, disconnecting the OS. Road tested pretty good.

Also hard starting and missing above 3100 rpm with OS unplugged.

Lewis

Also...Seems the cruise control is also kaput without the OS plugged in.

Your os may be toast. PM diesel pro he can tell you what they cost and what it entails to take it out. I do know it needs to be done w/ the pump mounted on the truck. You may try an optic bump and see if that helps. search optic bump for the instructions.

turbodiesel.no shows how to do an OS surgery...been there done that - easy to do just make sure everything around the IP is SPOTLESS!!!

So I dropped the truck at a good Stanadyne shop today and they were going to do some troubleshooting. These guys know these things backwards and forwards so I trust them to sort out the diagnosis. I'm pretty sure they are going to tell me it's an OS, and they have already told me that to do that they will have to remove the pump and put it on a calibration stand.

Anyway...Just waiting to hear what they are going to say. In the meantime, anyone have an extra OS laying around?

They want to put it on a stand to do the OS. What's the worst that can happen if I do it myself?

I've already thrown so many thousand dollar bills at this truck that I just can't do it anymore. I know a new pump would be a a good idea, but I just can't swing it right now. I'm looking to get this thing back to work and running fair for a year or so. At that point, perhaps I could throw a new pump on it.

Anyway...Maybe they will diagnose a small wiring problem and everything will be cool. I'll hope for the best and expect the worst.

They want like 350 for a new OS uninstalled.

Cheers,

Lewis

How much are they charging you? Just to take the pump out you are looking at at least $300 and then to put it back in another $300 and if they do replace the os you are looking at another $300. You are looking at $900. If it were me personally I would get a rebuilt pump from Diesel pro and have them put that in. At least you'll get a 6 month warranty w/ it. If those guys replace the os and something else on the pump goes out you just paid for the cost of a rebuilt pump. So basically my 2 cents is to have them put in a rebuilt pump. You should have put out an APB on diesel place to see if there is anyone in your area who could have helped you out.

ps. I know what it is like to throw money at something over and over. It sucks!

Replaced the optical encoder and re-timed w/tech II. Starts nice, drives nice. I'll feel better after I get a thousand miles under my belt, but things seem good after 200 miles.

Lewis

Replaced the optical encoder and re-timed w/tech II. Starts nice, drives nice. I'll feel better after I get a thousand miles under my belt, but things seem good after 200 miles.

Lewis

Is optical encoder same as optical sensor?

Also, what did you end up spending on this repair.....if you don't mind?

Thanks,
Louis

Replaced the optical encoder and re-timed w/tech II. Starts nice, drives nice. I'll feel better after I get a thousand miles under my belt, but things seem good after 200 miles.

Lewis

Optical encoder? That's a new one. Same as optical sensor? How much did that part cost? I'm certain I've got a bad sensor, but those cost so much you're better off (financially) to replace the whole pump.

Encoder/sensor...Tomatoe/tomatoe. Whatever. The Stanadyne shop that did the work referred to it as the optical encoder sensor. I think we all know WTF we're referring to here. BFD.

312.00 for the part.
112.00 to diagnose, r&r encoder, and set the timing.

What did they charge you?


Louis

Cedar Grove - where is this Stanadyne shop at? I'm over in Raleigh and it'd be nice to know a stanadyne joint is around here somewhere...

Optical encoder? That's a new one. Same as optical sensor? How much did that part cost? I'm certain I've got a bad sensor, but those cost so much you're better off (financially) to replace the whole pump. I,ve a brand new one,. stanadyne #33883 yours for 150.00
nick

I,ve a brand new one,. stanadyne #33883 yours for 150.00
nick

this is a new optic sensor? is it still for sale? Where did you get it? the local shop wants to charge me $250.00 for just the sensor?

this is a new optic sensor? is it still for sale? Where did you get it? the local shop wants to charge me $250.00 for just the sensor?

yes its a brand new one,. it was bought for a "just in case" scenario,.
never used,.
nick

yes its a brand new one,. it was bought for a "just in case" scenario,.
never used,.
nick

too late. Local pump shop sold me a new one for $228.00 this morning. Got it in and, seemingly, the problem is gone. I'll let you know in a few days.

All in all pretty easy. I think I could get it out, back in and running in an hour or hour and a half now. Definitely not as intimidating as I feared.

follow up...

been about 5k and the optic sensor replacement completely fixed the problem.

Jason

I bet that would have fixed my problem. Dang it. New pump for me.

I bet that would have fixed my problem. Dang it. New pump for me.

I was about 15 minutes away from buying a reman pump, but was lucky enough to have a good, honest pump shop nearby. The owner was honest enough to tell me that 90% of the time when the IP is "shot" it's just the OS. It was a bit scarry opening it up the first time, but no longer. It's a 30 min job start to finish now.

should have kept my mouth shut. The Fuel solenoid started acting up (either full throttle or idle, but nothing in between). I ordered a new IP from Pensacola Diesel last week, it arrived right before the weekend and I installed it last night.

Night and day. Truck is much quieter, and gone is the loping "shudder" at an idle that the truck has had since day one. Hopefully, this is the last post on this thread for a long time....

All said and done, it took six hours to R&R the IP. More intimidating than difficult.