Turn down the fuel

[nlines]

The only thing stopping me from driving my 1990 1/2 ton Suburban is the black smoke that it produces when I step on the pedal, it is way to much.
First thing was a new air filter... no difference
Second thing was get rid of the EGR manifold same result.
Advancing the Injector pump helped with the smoke at idle.
I am left with turning down the fuel delivery. Has anyone ever tried to reach the screw inside the pump. I have taken the top off the pump and still I can not get the governor out. Forget reaching the cover on the side of the pump. It looks like I am going to have to remove the intake manifold again to gain some more room. Any suggestions?

[john8662]

You gotta remove the top cover, then the governor.

Removing the gov isn't bad, just unscrew the bolt that goes in the back of the housing (requries an allen wrench), once that "guide stud" is removed, simply rotate the throttle manually and remove the governor/spring when you get the throttle positioned correctly.

Underneath the govenor you'll find the hole going down into the pump to adjust the metering.

Now the trick...

You have to rotate the engine (bar it over) until the fuel metering screw is visable (to be turned).

Carefully re-install in reverse order, insuring nothing binds, and that the top cover shut off solenoid tang doesn't bind.


In Conclusion, it does sound as though you have too much fuel, possibly an incorrect injection pump on the engine (turbo pump on n/a engine).

[nlines]

Thanks for the help,
I have tried getting an Allen key in the guide screw socket head. It did not seem to go in all the way. The intake manifold is just a little to close, anyway I put a extension on the Allen key but the screw was to tight. I am going to get a Allen 3/8" drive bit and try again if I can get it in the screw. I did not know that there is two different pumps for turbo and non turbo.
Cheers,Nick

[opto]

A more fun way to do it is to get a turbo that can supply air for the fuel

[john8662]

Thanks for the help,
I have tried getting an Allen key in the guide screw socket head. It did not seem to go in all the way. The intake manifold is just a little to close, anyway I put a extension on the Allen key but the screw was to tight. I am going to get a Allen 3/8" drive bit and try again if I can get it in the screw. I did not know that there is two different pumps for turbo and non turbo.
Cheers,Nick


There are two types of guides screws, one that just has a head on it, and another that has both the head and a lock-nut. If it has a lock-nut, you'll need the 13mm wrench to loosen it first, then the guide stud comes out.

The guide stud with the lock-nut on it would normally be seen on 6.5L pumps, and all the 6.5 Turbo MFI pumps.

If you have this... There is the smoke.

[nlines]

Saturday morning just before the rain started I managed to loosen the guide screw, It took a pair of Vicegrips on the screw head to break it loose. Now I have turned down the fuel and am worried about any small particles of dirt or other stuff that might of fallen into the pump.
Is there a way to clean out the pump before I close it up?

[john8662]

Just suction all the fuel out that you can, taking with it some of the debris.

No, not really a good way to clean the pump insides, this is one of those things that requires keeping things really clean during your work within. Typically, these pumps are built at a diesel injection shop in an assembly clean room.

Good to hear you got it turned down, that guide stud is usually pretty tight, not because it's torqued in there real tight, just because it get's stuck because of the difference in alloy (steel into alum.). About half of the time that stud's head breaks in the allen key area...

J