6.9 is down revised

[5.0ohsoslow]

I have a stock 6.9 except for little pump turn up and a stack. The truck started sounding like and old farm tractor about a month ago. Put-Put-Put... I noticed throughout the month (only drove it 4 times) the rpms droped from 700 to 525, along with the tractor sound. The other day I drove it and on the way home it started running even sicker, it started to pour on the gray smoke under very light throddle(egt-500), blacker under any more(egt 700-900) and hessitated seriously in 3rd and 4rth gears. The egt's stayed higher than normal even after I returned it to idle. I pulled off the air filter and a very very loud almost knocking noise acompinged the put-put! With the air filter on the "knock" is much much quieter. The motor also is shaking around in the truck much more than normal. Any more than the 525 idle it feels like it will take flight!!! The rpm increase is sluggish and higher in the rpm range 2000 can be accompnied with a backfire and popping noises.

I do not know about the life of the ip or injectors.
1983 f250 6.9 Granny Low

All help is appreciated!!!

 

[FordGuy100]

Sounds like the sound could be some seriously off timing. But I suppose it could also be that you dropped an intake valve. Others should have a better idea of whats up.

 

[5.0ohsoslow]

I pulled the valve covers and inspected the heads. Then ran the motor with the covers off. All the springs brought the valves closed. Notices that the rear pass cylinder smoked white-gray from the pushrods.

I think it is the ip but i thought that someone might have had the same simptoms on their truck and give me a comformation.

 

[5.0ohsoslow]

Does anybody know what is wrong with this piece of junk?

 

[icanfixall]

How many miles on the injectors? You may have an injector knock and need a set of injectors. If an injector hangs open or the spring weakens it will inject fuel early and cause a fuel knock. Kinda like a gasser preignition knock.

 

[waynebo]

you sucking air somewhere,find it,fix it and go truck'in

 

[69oiler]

how old is the fuel filter? if that checks out my money's on the IP

 

[5.0ohsoslow]

The fuel filter is new!
The injectors are old not for sure how old.

I have an extra set of injectors i am going to throw on and see if that is the problem.

Would a stuck open injector really make that much noise and cause that much hesition i mean it is really bad it feels as if it will fly apart at 1500 in neutral. After that it starts getting really ugly-very loud popping!!!

 

[5.0ohsoslow]

It is not the injectors i replaced them!

It must be the pump. Just hard to believe because of how it is acting.