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catmech69
catmech69, Lead Technician
Category: Heavy Equipment
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Experience:  25+ years Diesel engine tech
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1991 GMC: cat engine..the proceedure to set the fuel injector rack

Customer Question

I have a 1991 GMC with a 3116 cat engine I need to know the valve settings, the injector height settings and the proceedure to set the fuel injector rack. Engine serial no. 2BK05945 Any help is greatly appreciated. Thanks
Submitted: 7 years ago.
Category: Heavy Equipment
Expert:  Matthias replied 7 years ago.

Hello there

 

Do you have the tools needed for this procedure?

 

Matt

Customer: replied 7 years ago.
yes i believe we do. Dial indictors, micrometers, feller gauges.
Expert:  Matthias replied 7 years ago.
ok, hang on i will get you the whole procedure

Matt
Expert:  Matthias replied 7 years ago.

Valve lash check

 

Inlet
0.30 to 0.46 mm (0.012 to 0.018 inch)

Exhaust
0.56 to 0.72 mm (0.022 to 0.028 inch)

 

If outside these ranges set to the following spec

 

Inlet
0.38 mm (0.015 inch)

Exhaust
0.64 mm (0.025 inch)

 

 

 

 

 

A - exhaust, B intake

 

The injector procedure is comming next

 

Matt

Expert:  Matthias replied 7 years ago.

graphic

 

 

Customer: replied 7 years ago.
this directs me to a cat secured web site. A user id and password XXXXX XXXXX for this. Which we dont have.
Expert:  Matthias replied 7 years ago.
can you see it now?
Customer: replied 7 years ago.
yes i can see the picture, but I still dont have the procedures. Also the picture you sent with the valve lash does not show up.
Expert:  Matthias replied 7 years ago.
I will send you the procedure, the picture only shows wich ones valves are intake and exhaust. So you do have two dial indicators for the injector adjustment procedure?

Matt
Customer: replied 7 years ago.
YES
Expert:  Matthias replied 7 years ago.
Sorry,

I will get all the info together with pictures

Matt
Expert:  catmastertech replied 7 years ago.
Timing hight is 64.22mm.
Static fuel setting is 8.02mm.
Int. .015 " Ext. .025 "
Tooling should have a copy of NEHS0610 instructions to detail adjustment procedure.
128-8822 Fuel System and Governor Tool Group . This is the latest and the easiest tooling available.
I can't find the info anywhere else. I can recall from memory the basic setup though.
On TDC #1 adjust valves 1,3,5 & 1,2,4 injectors 3,5,6.
On #1 exhaust adjust 3,5,6 and 2,4,6 injectors 1,2,4.
You will notice which valves are down on you can tell if you are following the correct pattern. I can't remember if it is intake or exhaust so, double check the valves that are down.
Expert:  catmech69 replied 7 years ago.

Put the No. 1 piston at the top center position on the compression stroke. Refer to Testing and Adjusting, "Finding Top Center Position for No. 1 Piston".

With the No. 1 piston at the top center position of the compression stroke, an adjustment can be made to the valves. Refer to Testing and Adjusting, "Gear Group (Front) - Time" for the information that is required in order to adjust the valves.
Note: Before any actual adjustment is made, lightly tap the rocker arm at the top of the adjustment screw with a soft mallet. This will ensure that the lifter roller seats against the camshaft's base circle.


Loosen adjustment locknut (3) .

If there is not enough clearance in order to insert the feeler gauge between rocker arm (2) and valve (1), turn adjustment screw (4) counterclockwise in order to increase the clearance.

Place the appropriate feeler gauge between rocker arm (2) and the valve (1). Then, turn the adjustment screw in a clockwise direction. Slide the feeler gauge between the rocker arm and the valve. Continue turning the adjustment screw until a slight drag is felt on the feeler gauge. Remove the feeler gauge.

Tighten adjustment locknut (3) to a torque of 30 ± 7 N·m (22 ± 5 lb ft). Do not allow the adjustment screw to turn while you are tightening the adjustment locknut. Recheck the valve lash after tightening the adjustment locknut.

Remove the timing bolt and turn the flywheel by 360 degrees in the direction of engine rotation. This will put the No. 6 piston at the top center position on the compression stroke. Install the timing bolt in the flywheel.

Adjust the valve lash on the remaining valves. Refer to Testing and Adjusting, "Gear Group (Front) - Time" for the information that is required in order to adjust the valves.

Repeat Step 3 through Step 6 for these valve adjustments.

Remove the timing bolt from the flywheel after all adjustments to the valve lash have been made. Reinstall the timing cover.

The following procedure may be used to synchronize the unit injectors and the following procedure may be used to adjust the unit injectors.


Stop the engine and turn the electrical system to the OFF position.

Remove the fuel shutoff solenoid.
Note: If the fuel shutoff solenoid is inaccessible, the following steps may be followed.


Turn the engine start switch to the ON position. Briefly engage the starter. Do not start the engine. Return the engine start switch to the ON position. Do not turn the engine start switch to the OFF position.

Turn the battery disconnect switch to the OFF position or disconnect the negative terminal of the battery. This will leave the fuel shutoff solenoid in the OPEN position.

Remove the valve cover.

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Illustration 1 g00998517



Remove bolts (1) that attach the valve mechanism cover base.

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Illustration 2 g00998519



Attach Tooling (A) to the rail for the fuel (2) .

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Illustration 3 g00998587



Install Tooling (B) in hole (3) for the valve mechanism cover base that is near the No. 1 cylinder. Attach Tooling (D) to Tooling (E). Insert Tooling (E) into the hole in Tooling (B) .
Note: Orient face (4) on Tooling (B) parallel to the crankshaft.


Install the other Tooling (B) in hole (3) for the valve mechanism cover base that is near the No. 2 cylinder. Attach Tooling (D) to Tooling (E). Insert Tooling (E) into the hole in Tooling (B) .
Note: Orient face (5) on Tooling (B) parallel to the crankshaft.


When the engine is viewed from the flywheel end, rotate Tooling (A) in a counterclockwise direction. You should feel resistance to a spring. Turn Tooling (A) past the start of the resistance of the spring. Zero out Tooling (E) for both the injectors.
Note: Do not turn Tooling (A) all the way. This will lead to an inaccurate synchronization.


When the engine is viewed from the flywheel end, rotate Tooling (A) in a clockwise direction through the entire range of motion. The readings on Tooling (E) should change as the position of Tooling (A) is changed. Take a note of the values and of the difference in the values.

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Illustration 4 g00998590



If the values are within a tolerance of 0.05 mm (0.0020 inch), no adjustment is required. If an adjustment is required, install Tooling (F) on the locknut at the base of the unit injector.

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Illustration 5 g00998591



Loosen the locknut with the outer rod (6) and adjust the injector with the inner rod (7). Tighten the locknut when the adjustment is complete.

Repeat Step 8 through Step 11. Illustration 4 shows two unit injectors that have been properly synchronized.

Once the first two injectors have been synchronized, synchronize the remaining injectors by following the previous procedure. Remove Tooling (B) from the No. 2 cylinder and move to the No. 3 cylinder. Do not move Tooling (B) from the No. 1 cylinder. Always synchronize the injectors with the first injector. The first injector is the reference point for all the injectors.

Once all the injectors have been synchronized, remove all the tooling from the engine. Install bolts (1) that attach the air intake housing. Replace the valve cover and tighten the bolts that attach the valve cover. Refer to Specifications, "Valve Mechanism Cover" for instructions.

     
     
Customer: replied 7 years ago.

I stayed at work till 7:15pm Friday March 6 waiting for a response from you guys. I ended up getting the local Cat dealer in here to set the valves and injectors. It took you guys over 28 hours to get the info here. By then the truck was on the road for over 7 hours. I did not look at the info you sent to see if it is good or bad info.

Expert:  catmech69 replied 7 years ago.
Dear XXXXX,
We apoligize for the time consumption, as i'm sure you noticed the price of our invoice compared to the price of the CAT invoice. most technicians here do this as a hobby to help people with a low cost alterenative to HE repairs, including your truck, and it is mostly done in there spare time or there day off. if time was of the essence for you then you probably should have gone to the CAT dealer to begin with, but you chose to try and save a dime and do it the cheap way. the average hourly rate for a CAT technician is about 100 bucks, thats per hour, there is good reason for this, CAT equipment is the BEST there is, but it take ALOT of special tools to perform even the smallest projects. We here at JA tried to help you from are hearts, to help you to save a dime. in this particular instance we didnt meet your standards, and we understand your frustration. the information that is provided to you here is good material, I hope that you can save it for the next time you need to adjust your valves and set your timing. but please don't be upset with us for trying our best to help you !

thanks for coming to JA and we hope you return.
good luck with your Truck!

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