Advise needed have four codes/check engine light

[3500 dually]

Need some advise, the truck lost alittle power on the way home and check engine light came on then went back out. Ran codes when I got home and here is what it gave me, " 29, 35, 49, 78". I cleared the codes and have not come back yet. Did not loose alot of power just felt sluggish. Thanks David

 

[Brooklyn Tow]

Check grounds, of course.......Also, are you using any fuel supplement or oil (2 stroke or SAE30 Non Detergent?).....If not, give it a nice dose of BOTH.

 

[Acesneights1]

78 is wastegate IIRC. Blowing alot of balck smoke on heavy accel ? Probably the solenoid on the drivers side valve cover Has Vac lines to it and then to turbo wastegate. Check lines and wires, nif good probably bad sol.

 

[dangerousdave]

None of those codes are relatedto each other. I'd look at the grounds.
After that, if they reappear, look deeper; connectors to the ECM; ECM Pinouts - Diagrams found here
http://www.thetruckstop.us/forum/showthread.php?2624-Wiring

 

[JiFaire]

I agree with Louis... 35 is an IP timing fault, often caused by lack of fuel lubricity... clear the codes, pour about 8oz of 2-stroke oil and 8 oz of Powerservice into your next tank of fuel and it will probably not show up again..

When you get a code 35, often lots of other codes can cascade off it... I don't know why 29 and 49 would appear, but I bet without a 35 they stay away. Code 78 though, is because when you get a 35, your PCM will shut down the boost (it's in the engine protection logic). Fix the 35, no 78. Kenny's suggestion won't hurt anything, either.. always check/clean your contacts before replacing things.

And, as Dave mentioned, clean your grounds. That should be once-a-year regular maintenance for the 6.5.

 

[Acesneights1]

I recently worked on a 94 with 35,78. They were unrelated. The truck had a faulty boost sol. The 35 is the IP on it's way. He's been using the additive/stroke to prolong it. After replacing the sol the 78 never came back.

 

[3500 dually]

Thanks to all, I will try all this this week and let everyone know what I find. Have a busy week this week before surgery on friday.
Once again I want to thank for this great web site and to all the good people on this site.
David

 

[JiFaire]

I recently worked on a 94 with 35,78. They were unrelated. The truck had a faulty boost sol. The 35 is the IP on it's way. He's been using the additive/stroke to prolong it. After replacing the sol the 78 never came back.

Yep, they can be unrelated, too, but normally if you clear 'em and 78 goes away, they're tied.

 

[buddy]

Yeah, the DTC78 is the power loss primarily because it causes defuel. You can have it or the 35 separately. 35 could be IP, or PMD, or air in the fuel. A 35 sets a constant pulse width, so it cannot get as high in RPM with enough fueling, so I can see where if you tried running it past 3000rpm with a 35 the fueling may not support the boost it wants.