Engine/Transmission (1994 - 1998) too much smoke AND boost

[tmassey]

last week as i was getting onto the freeway I happened to glance at my boost guage and expected to see it at its normal 32-35psi and insead saw it was in the 40-45 range and there was alot more smoke and egt than normal. This truck is my daily driver so i havent messed with anything in 3 or 4 months, just filters and oil. what would cause the sudden over boosting and smoke all the sudden, does this have to do with ulsd? or are my injectors finally going out at 257000mi? any ideas would be appreciated, thanks

 

[RDyson]

Sounds like for some reason you are getting more fuel than normal. Is it running rough?



Randy

 

[tmassey]

no, it still runns just as smooth as it normally does. nothing has seemed to change other than the extra smoke and boost

 

[hdm48]

This happened to m a while back and it was kinda freaky. It turned out that the star wheel had backed itself off. Why? I'll never know because I went to Dynomite Diesel and got a Aneroid spring kit and replaced everything.

It's much more better now.



Dave

 

[Forrest Nearing]

sounds like fun



could the fuel plate have slid?

 

[champspa]

could the overflow valve have stuck , I know a guy that pulls tractors and all they do is put a clamp on that overflow and it shoots twice the fuel it seems. if the fuel goes up the boost will follow.

 

[PKemp]

champspa: clamping the line will only raise input pressure to the injector pump. The volume delivered to the compression chamber is still dependent on the delivery valves, injectors and injector timing. Clamping the line insures a higher delivery pressure to make sure that everything after the fuel pump doesn't "starve" on a big pull. Not something you would want to do on a daily driver or for very long.

 

[tmassey]

thanks for the replies,! the overflow valve was changed about 4 or 5 months age and the fuel plate already full forward so it cant slide. today i readjusted the star wheel and it took care of some of the smoke but the boost is stilll above what it has been for the last year and a half. could timing have anything do do with this or am i just worring for no reason?

 

[Missouri Mule]

I don't think timing would slip forward (advance).

Could the vacuum hose going to the AFC be plugged?

 

[Forrest Nearing]

timing wouldn't cause that much increase in fueling and boost... a plugged AFC line would have the opposite effect.



is it possible that you've lost your wastegate control either a torn diaphragm or bad/broken/clogged signal line to the wastegate, thus increasing boost, thus increasing the amount of compression on the AFC spring?