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Discussion Starter #1
My truck is stumping all to date, some say rebuild the IP, I don't want to drop the $$$!

Getting Code 78's in all kinds of conditions, checked out wastegate train.
I found 15" of Hg vaccume, fixed leaking vacuum lines. Also replaced manifold sensor and w.gate solenoid

Wastegate opens on kickdown to 3000rpm. I don't have a manifold pressure guage (yet)

I can't see why the black smoke would start after the turbo rebuild, intuition is that turbo boost should give leaner mixture. I am finding that I can avoid black smoke by holding narrow rev band, and easing into acceleration, tromping the pedal blows smoke,
(course I wouldn't drive like that if I didn't want to see what happens).

SES light on and off probably code 78 doesn't seem right but it's there, what else might it be pointing too?

The ancillary problem is the ragged rattley running of the engine.

Additional info: At turbo replacement (Monday) engine had no start condition. Only explanation ?? seemed no lifter pressure after oil change, (with reprimed filter cartridge), started after 10 minute wait, failed to run past 5-10 seconds, then restarted after 10second crank & ran normal.



Anyone believe that this injection pump is needing rebuild? What am I missing?







 

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Tie the WG shut with baling wire, give it a run up the street, see what happens.
 

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Black smoke after turbo replacement means one that the injection pump is not the problem.

Either you got a bad turbo, of it was installed incorrectly.

Pull the air intake boot off of it and check for play/wear on the compressor wheel inside the turbo. If it clanks around, take it back. If it doesn't, check that your WG actuator has good vacuum supply and does hold vacuum.
 

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Discussion Starter #4
Can overmileage (80kmile) injectors cause smoking and rattley operation, also experience slight surging on heavy trailerpulling.

Is there any othyer reason for Code 78 shy of faulty wastegate/turbo operations, i.e. can IP or I's affect the operation sufficiently for 78's to cycle.
 

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Map sensor is probably failing - rectangular black module in the intake plenum.

DTC78 means over-Boost

Bad fuel causes noisy engine operation

Plugged air filter causes black smoke
 

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You need to update/add your signature. Include all relavent info about the truck and possibly some things you think aren't substantial. This will help others diagnose what is possible/probable.
 

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Discussion Starter #7
Thanks for your interest, I've tried to summarize on sig line.

Just flashed a code 62, which is pointing toward the PCM. As the manifold sensor is new. Also not getting adequate boost, variable at best.
 

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Has it gotta EGR?
 

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Discussion Starter #9
No EGR, single solenoid for frequency valve
(believe ya'll call it a "Turbo wastegate solenoid")
BTW the crankcase vent filter ("Engine Depression Regulating Valve) is new also, crank case is pretty "fumey" with the tuna can pulled and 6.5 idling, the opening looks like a pot of hot black cowboy coffee.
 

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Check the wires and pins in the MAP sensor for firm connection, no frays, bent pins, etc.

Remove intake duct from turbo inlet, see how shaft rotates, wiggles.

Crank engine, observe blade rotation at idle - keep sleeves, ties, hair, shop rags, leaves\sticks, wires, etc, outta the turbo inlet while running.

Won't develop Boost at idle or revving unloaded, so no need to try that

Can get a 30"-0-20psi gage from jcwhitney for 20 bucks.

EGT'll cost ya about 150.

Better yet - get Swedeburb's free GMTDScanBasic software for your laptop to read the PCM's idea of what's happening.

Try it - you'll like it.
 

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Heavy black smoke is usually no boost/over fueling condition. Is it possible that the smoke could be blue? This can be oil. With a new turbo you'd have to say that it's going to be good? How about the oil return line on the bottom of the turbo. No kinks or restrictions?
The way your driving off of the line your not calling for any boost so no smoke. After your up to speed the engine is getting plenty of air unless you call for more with your right foot.
It sounds to me like the wastegate system is at fault here. The ECM supplies the ground side for this operation, take a look at the pins at the solenoid or maybe any rub spots going toward the ECM (it enters the cab under the A/C accumulator).
One more real easy test is to move the wastegate rod with the truck running at idle, you shouldn't be able to.
 

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Discussion Starter #12 (Edited)
Checking connections this morning, tightened up MAP and codes are resolved. (KISS)

Fairly sure it's not oil. You're right it is a function of right foot, though a good pull up 25% grade brings steady streaming black smoke too. (not as much now as before vaccume leaks were fixed). If throttle eases, smoke clears. Pulling 8k+ pounds, it's doing the work.

I can move the wg linkage at idle, then it pulls forward and holds.

Questioning ECM, but leaning toward blaming Injection system for rough running and blacksmoke.

I'm putting it in a friendly shop (with scanner), do diagnostics (verifying inputs checking outputs); strong potential of rebuilding injectors & IP.

As you can probably tell I need this truck, it's my daily drive and tow vehicle for business, and daughter's competitive horses. (Which is worse?)
 

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This is kind of :eek:fftopic: but thinking of black smoke, my truck doesnt ever make any. I've never been around a diesel that didn't. It doesn't seem to matter what I do.:eek: No smoke. Any ideas or suggestions?
 

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though a good pull up 25% grade brings steady streaming black smoke too.
Holy crap, I didn't think there was any such thing as a 25% grade!!!:eek:
 

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If you can move the waste gate then maybe you don't have enough vacuum. that waste gate should not move at idle. IIRC (check FAQ) you need 15hg at the wastegate actuator
 

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If you can move the waste gate then maybe you don't have enough vacuum. that waste gate should not move at idle. IIRC (check FAQ) you need 15hg at the wastegate actuator
Who are you talking to?
 

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Could it be possible that the timing chain get worn over time and throw the timing off and be putting fuel and air into the cylinder at the wrong time and causing it to smoke? My truck smokes sometimes also but not all the time....does it worse when its hot and i have done everything to a stock setup that i know to do to help get cool air in there.
 

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This is kind of :eek:fftopic: but thinking of black smoke, my truck doesnt ever make any. I've never been around a diesel that didn't. It doesn't seem to matter what I do.:eek: No smoke. Any ideas or suggestions?
Unplug the vacuum line from the wastegate actuator. Then she'll smoke:D
 

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Discussion Starter #19
Vaccume is reading 22" Hg, (recall: new WG solenoid, MAP)
Currently new Optical sensor (yes it was bad, 8 new injectors:
Runs more evenly pulling 8000#-that good, pulls pretty good, blows smoke pretty good too, Code 78 comes on at 2000-2600rpm light holds for up to a minute. If I let off the throttle smoke clears, no codes. If I can increase the revs light's out too.
Power comes at higher revs, with light smoke, granted I've got the "wrong" tires 265vs245 (I fell for that "looks wrong" syndrome) if I were to do it again I'd go stock with the tires, guess what, it runs best at 70 mph, which is slightly over our local limit... 10-15% interstate grades, (drop to third for those 22% local hills) Been getting 14-15mpg towing or not uncorrected for tire size.

I'm wondering if there's any chance the PCM could change this situation, our mechanic and I rather doubt it, but what else to do? Is there any point to advancing the timing, right now it's on the spec.
 

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Hey, MtnDSL, I am wondering about the exhaust? My truck was doing the same thing, threw a code 78 unloaded going down the freeway if I put my foot into it. I don't pull anything yet, but I am going to be towing a 6,000 pound Travel trailer this summer. My truck was lacking power big time. I put a new exhaust on, and my transmission hickups were gone and I was laying rubber. Smoke dissappeared completely. Before the exhaust I could black out an entire freeway, especially going up those hills.

This is just a thought. :)

My truck is running alright right now.
 
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