CAT 3304-Timing the Injector Pump

[Bryant_955L]

I need some help understanding how to time the injector pump on a CAT 3304 PC engine. I tried starting my rebuilt motor this morning and it doesn't fire. My suspicion is the timing of the injector pump. When I tore down the old motor I simply put the motor at TDC and then remove the fuel pump. When I put the motor back together I simply aligned all the gears to the marks I made and installed the pump while the motor was at TDC. At this point I really haven't done anything to investigate. I may have other issues that is causing this condition as well. I decided to visit my favorite place and ask for help and any suggestions that I should try.

 

[Shimmy1]

Is it mechanical shutoff or electric? If electric do you have power at the solenoid? Do you have fuel at the pump? How about at the injector lines? At the injectors? Lots of things to check before we assume it's not timed properly.

 

[kshansen]

Is it mechanical shutoff or electric? If electric do you have power at the solenoid? Do you have fuel at the pump? How about at the injector lines? At the injectors? Lots of things to check before we assume it's not timed properly.

Agree need to fill in a few blanks by answering the questions Shimmy asked. You did put fuel in the tank and open the shut off valve right? Sounds simple but I was trying to start my snowblower the other morning and after four pulls on the cord remembered I had shut the fuel off.:Banghead One pull later it was running!

PS Even if you have it 180º off on timing it should start, run like crap, but fire up and start. BTDT!

 

[Mobiltech]

What is the serial number?

 

[Bryant_955L]

The machine is a 71J4718. I do have fuel on the low pressure side. I used the primer pump to make sure there was fuel in the system.

 

[Bob/Ont]

If the pump shaft had a drive tang on the end it is offset and can only go on one way. The timing is set correctly by putting the engine on TDC and adjusting the drive shaft with a timing fixture. If the pump had a tapered end it will time up with a pin.
Later Bob

 

[Bryant_955L]

The pump shaft is tapered. Also I was able to start the motor after repeated attempts bleeding the fuel lines. However, the engine doesn't run really well and there is a tone of black smoke at lower rpm's. In fact it seems as though there is one cylinder not firing. I did spray a very small amount of ether while the engine was running and the engine smoothed up considerably. Not sure what this means? But I am guessing that it is related to the fuel and timing. As I think about it now I am really not sure that I had the original motor at TDC on the compression stroke. I am hoping someone has experience and give me some direction.

 

[Bryant_955L]

Also can you help me with the pin etc? How it work etc?

 

[kshansen]

If the pump shaft had a drive tang on the end it is offset and can only go on one way. The timing is set correctly by putting the engine on TDC and adjusting the drive shaft with a timing fixture. If the pump had a tapered end it will time up with a pin.
Later Bob

I would start by using a puller to loosen the gear on the accessory drive shaft on its taper. Then use the timing tool to locate the tangs of the pump drive end in the proper position. Next you need to locate the engine at top dead center (TDC) on #1 compression stroke.

There should be a 1/4 pipe plug in the flywheel housing under the starter. Remove this plug and while slowly turning engine over by hand using a 3/8 bolt long enough to hit the flywheel through the pipe plug hole you should be able to find the threaded hole in the flywheel. This locates TDC, you then need to insure that you are on the compression stroke on #1 cylinder, both valve should be loose. If not turn engine another complete turn to get #1 on TDC. Then tighten the nut holding the gear on the accessory shaft. Remove timing tool and bolt in flywheel housing and install fuel pump.

I hope this makes sense and if anyone can clarify it better go for it! It's been a few years since I've had the pleasure of working on a 3300 series engine. I always thought they were about the most basic engine ever built.

 

[Bob/Ont]

Your pump must have a large plate covering the side of it. That would be a sleeve metering pump. There is a raised cover near the throttle lever with 3 bolts in it, 2 5/16 and 1 3/8 (9/16 hex). Take out the 3/8 bolt/plug and get a new 1/4" drill bit. push the drill bit into the hold with tip outward, turn the engine until the drill slips into a slot in the shaft and locks the pump. The pump is now timed to TDC#1. Pull the drive gear off of the shaft. Now turn the engine until the bolt will go into the flywheel as Kshanson described. Make sure both valves at #1 are loose, you now have the crank timed and can install the bolt in the pump shaft and torque to 100 Lb Ft. Note tighten bolt slightly then remove the drill bit to complete the torque of bolt. Back up the engine 180 deg then turn up and check the bolt and drill will go in their holes. I trust you timed the balancer shafts in the bottom of the engine.
Later Bob

Also can you help me with the pin etc? How it work etc?

 

[Bryant_955L]

Thanks for the info. I will try this and let you know. Again thanks for your help.

 

[Bryant_955L]

Yes, I did set the balancer shafts when I installed the oil pump.

 

[Bryant_955L]

My pump is a scroll type pump. View attachment 128332 My question is do you absolutely need the "timing fixture" plate (8S5417) to make the pump timed with the motor?

 

[Bob/Ont]

Yes it must be timed exactly, would be a good investment to hire someone with the correct fixture to time it for you rather than buy the fixture.
Later Bob

 

[kshansen]

My pump is a scroll type pump. View attachment 128332 My question is do you absolutely need the "timing fixture" plate (8S5417) to make the pump timed with the motor?

Not sure if a drip timing method will work on this system, anyone know this?

If it is of any help I have one of those 8S5417 sitting on the bench out in the garage that I could loan you. The only problem is it's located in Central NY.

If you can not borrow one from someone local if you pay shipping both ways I could send it your way. I believe the cost for a new one is around $125. Could check on Ebay.

 

[Bob/Ont]

There are no degree marks, just TDC. On the bench a degree wheel is put on the pump shaft and a spacer and depth mic are used to find the correct timing shim for each barrel to sit on. Once that is done the drive tang only needs to be correct on the engine.
Later Bob

 

[Bryant_955L]

Does anyone in the forum have a timing fixture they would rent or sale? Or does anyone know where I could get one? I looked on the internet and I can't find any. I am going to call my local Caterpillar dealer tomorrow and see if they have one for rent or sale.

 

[Bryant_955L]

Not sure if a drip timing method will work on this system, anyone know this?

If it is of any help I have one of those 8S5417 sitting on the bench out in the garage that I could loan you. The only problem is it's located in Central NY.

If you can not borrow one from someone local if you pay shipping both ways I could send it your way. I believe the cost for a new one is around $125. Could check on Ebay.

I looked on Ebay this morning and found one to rent from New Zealand. Thought that was a little far to be reaching out for a fixture. I will check with my local Cat dealer tomorrow. If not I am interested in renting yours. Thanks for the help.

 

[Bryant_955L]

I purchased the tool and I have been able to fix the timing. Thanks to you all of course for the information you provided. Couldn't of done it without talking to this forum. Thanks!

 

[Bob/Ont]

Well Done
Later Bob