I am new with the diesels, grew up in fuel injected Jeeps, I was wonder if anyone knows where I can find, or can tell me how to time my 1990 7.3 standard truck, thanks

 

Timing is critical to a good operating diesel engine. These ones are not complicated, but "proper" timing can only be checked with expensive and apparantly rare tools, where I live even the dealerships don't have them! (I bought a Kent-Moore tach and time on e-bay- offered to load it to the dealer, wasn't interested). Given that info, if you have a problem that you suspect is your timing, general rule of thumb is that inless your IP is very worn, or someone has messed up the gear timing by pulling the timing cover when changing the IP, the scribe mark on the 12 o'clock position of the IP and gear cover should be almost perfectly lined up. Scibe on IP rotated toward the passenger side is advance. With my timing meter, I have verified that when the cold advance is on, the engine will rattle when accelerating, but the rattle will be gone once the cold advance cuts off, and you step on the go pedal, this is 8.5* BTC usuing the pulse type timing set up. At this point my scribe line is only 1/2 a line width advanced.
Lots of information is available here if you are having problems you think may be timing related, but give us some more info on your truck, turbo or not, etc. You should be able to list all that in your signature.

 

I belive the timing was OK but all of a sudden it quit taking fuel from the pump to the injectors, It is getting good pressure to the pump but that is where it ends, I checked the cervos in the pump by removing the top cover and they are working fine, my only other option at that point was to remove the pump. I find there is some slack(back and forth movement of the gear) in the pump. When turning over the engine the only fuel to come out was coming from the return line of the injectors. This is on a1990 7.3 natrual. I am getting the pump rebuilt but I am not sure if you time these like a car or is there another method or things I should look for.

Thanks Scott

 

The timing mark is found on a little plate that is on the front of the engine on the passenger side. The plate is mounted so it is very close to the main pulley on the lower front of the engine which is mounted on the vibration damper. On the side of the vibration damper, is a line, which when lined up with the line marked (O) on the plate, tells you that the #1 piston is at TDC(top dead center) You can see the line on the damper, and it points to the line on the plate with the (barely visible)O mark on it.You'll have to find a way to turn your engine over by hand. Make sure you remove the power wire to the injection pump(so the engine won't start)and then rotate the engine until you can line up the marks.

The engine rotates in a clockwise direction as seen from the front of the truck, and for every 1/4 turn of the engine(crank) each next piston will arrive at TDC. So, When the line on the vibration damper is at the 2 oclock position, cylinders 2 and 5 will be at TDC. When the mark is at the 5 oclock position, cylinders 7 and 6 will be at TDC, 8 oclock has cylinders 3 and 8 at TDC, and back to 11oclock, 1 and 4 will be at TDC.

Cylinder numbers are assigned 1,3,5,7 on the left (passenger USA) bank from front of truck to back, and 2,4,6,8 on the driver's side (USA), front to back. Firing order is 1,2,7,3,4,5,6,8.

DieselDon info


If you have the original emission label on your valve covers, they gave the max pump fuel flow rate in mm3 at rated HP.

As I recall 6.9 was about 48mm3 sea level and 44mm3 for high altitude pump
7.3NA was about 54mm3 and 49mm3 for high altitude
7.3 IDI Turbo - 58 mm3 ( this is out of the Ford book )

Optimum timing: 6.9IDI ( Ford method ): .5-1.5 degrees ATDC
6.9IDI ( Navistar method ): 6-7 degrees BTDC
7.3 NA: 8-9 degree BTDC*
7.3 IDI Turbo: 8-9 degrees BTDC*

Anything above these, the engine get's pretty noisey.

* helps engine starting. Original timing was 5-6 BTDC and engine cranked a long time ( at least in comparison to 6.9 ) before starting.

 

how do you aling the timing gear as it was pulled off with the pump, do you have to pull the water pump and get down inside to the a mark on the other gears?

 

You don't have to pull the pump. turn the motor over slowly and take a pick tool and let it rub on the gear. You will "feel" the marks. Just get it on the right one. It is pretty easy.

 

I have the truck running, but I find it lacking power and blowing white smoke, I am going to try to advance the timing any suggestions?