Engine/Transmission (1994 - 1998) Rebuilt 5.9 Black Smoke Problem.

[Voodoo Trucker]

I have a 97 Dodge 2500 4x4 that was just rebuilt that has a black smoke issue. It black smokes off idle until you get about 3-5 psi boost and then cleans up. Or if you are @ cruise (low boost) and you go to pass some one. The only thing that has been done is that it is using the 1st. gen pistons in it which I was advised to run by another well known company. It is also running a new head (Cummins knock off) with stage 1 porting. The truck is lifted running mud terrain tires with ATS built transmission. 4" exhaust afe stage II intake, and ATS intake. Its running 215 injectors #10 plate and 17 degrees of timing the block was cut for fire rings using Scheids gasket and 12mm. ARP's. I have talked to other companys that have put P7100's on first gen's using the same CA 180hp pump with no black smoke issues. The only thing that I can think of is the 1st. and 2nd. gen cams are different. The profile of the 2nd gen cam may not work well with that type of combustion bowel shape. Any ideas? Because I am about to pull it and slap the OEM pistons back in. Sorry for the loooong post. HELP!

 

[raychem]

WHat has been done to the pump. Black smoke? is it heavy or hazzy. Were the injectors rebuilt or new????same for the pump and what was the cause for the engine being rebuilt? In my experience, black smoke is almost always a fuel problem and not an engine problem, pulling out and changing the pistons will not solve the problem. Please give me some details on the above questions so we know how to attack the problem.







Richard

 

[BPonci]

Sounds like a low drive pressure/cylinder pressure issue maybe due to the different pistons. I had the same type of issue and it was due to the lower comp pistons and the wrong cam centerline. Changed the cam and its liveable.

 

[Voodoo Trucker]

WHat has been done to the pump. Black smoke? is it heavy or hazzy. Were the injectors rebuilt or new????same for the pump and what was the cause for the engine being rebuilt? In my experience, black smoke is almost always a fuel problem and not an engine problem, pulling out and changing the pistons will not solve the problem. Please give me some details on the above questions so we know how to attack the problem.







Richard

The pump was rebuilt 2 years ago and I had my injection guy recal. it before putting it back on the rebuilt engine. A couple of the bp's where a little off and where adjusted. 4k springs and rack stop where added the afc was left in the stock location and the star wheel is set at stock spec. The AFC was checked on the test stand along with the timing(17). The smoke is like what you would see from the stacks of a semi taking off in low gear from a light and after grabbing the next gear(darkish haze) but, then cleans up as it builds boost.

 

[Voodoo Trucker]

Sounds like a low drive pressure/cylinder pressure issue maybe due to the different pistons. I had the same type of issue and it was due to the lower comp pistons and the wrong cam centerline. Changed the cam and its liveable.

The pistons are higher compression ratio of 17:1 vs. 16. 5:1 stock. Compression psi was checked at 400 psi. with the engine on stand prior to ever starting it. The reason for pulling the motor was because the block was warped . 004"in. It was the second head gasket in a year and half. Upon removing the block I found that cyl. # 1 was scord, most likely due to the last guy who replaced the gasket. So the deck surface had . 008"in removed at the highest point and all bores punched 20 over. Piston prtrusion was . 026"in. (spec. . 024-. 028"in) BPonci was it a stock cam or a faulty grind?

I don't know if its due to lack of air or due to fuel air mixing or the whole combo.

 

[DJWyckoff]

1st and 2nd gen cams are diffrent I was told that a first gen cam would make more power (I was discussing P-pumping a 1st gen and parts needed)

 

[BPonci]

It was a aftermarket cam. Nothing wrong with it just the wrong one installed.

 

[Devan Manis]

You never mentioned if the injectors were new or what, maybe the pop off is screwy?

 

[Voodoo Trucker]

You never mentioned if the injectors were new or what, maybe the pop off is screwy?

The injectors are new and I also tried some other injectors with the 155 degree spray angle which is the same angle as the 1st gen injectors. 2nd gen injectors like the 215 hp have a 145 degree angle. I also played with the washer thickness and it did not help.

 

[JoshPeters]

What turbo do you have on it?



It sounds like your starting to get into the throttle and boost isnt' coming up fast enough.



Josh