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.
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!
What is the serial number?
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.
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
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.
Also can you help me with the pin etc? How it work etc?
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.
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
Thanks for the info. I will try this and let you know. Again thanks for your help.
Yes, I did set the balancer shafts when I installed the oil pump.
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?
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
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.
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
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.
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.
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!
Well Done Later Bob
Bryant, it is possible to spill time this engine with the fuel pump that you have fitted, I have done this task a few times when I have not had my lock plate, this is via a timing disc (bit of plastic) that is of no weight that I always keep in my chariot, I know its not an issue now that you have the correct tooling but it not a hard task to cope with if you have a bit of plastic, anyhow the learning curve is on full flow for you, so please dont be slow to ask about anything that you are not sure about in future before you pull things to bits, as 2 grind marks on the drive gears would possibly have saved you a few coins, oh and on the spill time thing the 3304/6 does have the TDC pin point, so with that set and the disc poked on the front of the crank and fuel in the tank its not hard as even a dummy like myself can cope, it helps to have the throttle control off the stop position though!!! very pleased that things worked out well tctractors p.s. my lock plate also fits the D8H/K compact pumps as I drilled it to fit and sold my D8 lock plate, so 1 tool fits all (sort-of)
A little more info? Is there a spec listed for how many degrees BTDC the injection starts? Guess I should just look in SIS, but hey I'm feeling lazy
kshansen, if you think I keep that data in my hollow head you are giving me a bit to much Cred' but I would have this detail in my heap of CAT tech/service books, the heap would be heading towards the 1 ton mark, so its a bit of a rummage to sort through them all, they start at the 20/22 and the 60 gas all the way through to the High drives, but anyhow you sound more interested with how you find the Degree off the front crank, well a fool can do this easily with a bit of welding wire or rod a clamp and a timing disc, my disc by the way is Motor Bike spec from my BSA and Norton days and is about 180 -200 mm Dia' after you poke the TDC pin in its holeyou stick the disc to the front pulley with a bit of tape in any position that gives you the easiest view as you only need a few of the numbers and it makes no odds what number is visible, then you clamp on the wire to the bit that does not turn like the Chassis for instance, then bend the wire to point to any number/position on the timing disc, then you need to do that thing with your fingers to work out how many marks/deg' you need to turn things back, it sort of gets things done and I will say its a lot easier to spill time a D342 (D8 motor) but by now I think you are on track with this endeavour. tctractors
That task is way above my pay grade.
Actually a pretty easy method, if, one has a spec. on the degrees BTDC injection is to start. I fully understand the methods to measure crank angle and TDC, anyone else familiar with setting the timing on a Cummins small cam? Real fun doing the VT1710 or KT1150 with the offset keys and pressed on cam gears! Done many Macks and IH 817's with Robert Bosh or American Bosh pumps. Most of them were done with air pressure watching bubbles in a jar of fuel oil. I did spend a little time on SIS looking for a timing spec for 3304 or 3306 engines with no luck. One problem with using the timing tool from Cat is it always depends on the condition of the parts in the injection pump and the skill of the person who adjusted those parts on assembly. Where "spill timing" would by-pass all that, assuming all cylinders were the same. With a little effort one could take it one step further and check each cylinder to see if there was one or more out of whack. Then this is not really helping Bryant, sorry for rambling on Bryant! Hope that 3304 is purrrrring like a Cat should!
kshansen, on the Cummins motors I get plenty of them to fiddle with, the 1710 and the later 28 with the revision on the firing order etc, the stepped woodruff key and all those shim things (gaskets) on the cam roller box's make any 855-14 L tough going to the simple 3306 with its basic engineering, we used to have a few Mack trucks here in the U.K. running usualy Low loader or Cattle Float, they took some hiding on our hills with rear axle U bolts needing a re-think but the rest held up reasonably well, anyhow I do have the Super spec book some place with all the targets you need to meet on the early CAT engines, I have posted pictures before in shop talk of big /small cam 14 L and 1710 vta 28's that I have pulled to bits, then as you said its not realy helping Bryant the owner of a new 4"3/4 bore lock plate much with our ramblings. always happy tctractors
All the ones I spill timed like this I did with a dial indicator and rod through the pre chamber. Cat lists the piston travel for the correct engine crankshaft location. And turn the pump drive gear till fuel just starts to drip from line; bolt up and recheck. Just make sure no1 is on its compression stroke, not exhaust ! plate makes it a lot easier tho !
Hi Merv, my plasic degree disc is always in my truck and easy to use on anything that rotates? rather than use use the Cummins Style dip measurment on piston height I would find my lock plate and use that, the times that I have spill set 300 series engines usualy involves someone that has done something to the pump, then I get called in because things fail to start, on the D342 motors they can get into a pickle in the gear chest after big hours, this is the best way to convince the owners that its due a Birthday. tctractors
You guys are great. The Cat is purring like it should. It is amazing to me just how crappy the engine runs with the timing off. I had all kinds of black smoke and the motor would only run at higher RPM's. I literally was thinking I would have to tear the motor down completely and start over. But with the help of this forum I was able to put my worries behind me. When I used the tool and timed the pump correctly this time I couldn't believe the difference on how the motor ran. There is no black smoke and the motor runs very smooth. I noticed in the manual that I need to run the motor at 1600 RPM for the first 4 hours to break it in. What does this Forum suggest for a break-in on the motor?
Just for the record static timing is 12.5 degrees BTC (0.099" of piston travel)
I’m also having issues with a 3304 75kW genset. I’ve rebuilt the engine three times now...has over 94k hours. The last overhaul included a new crankshaft in addition to cylinder kits. Punched in new guides, ground the valves and seats...32k hours on the cylinder head before rebuild. Changed out the seals and felts on the injection pump and replaced a few parts in the Woodward governor. First start couldn’t get the engine rpm to run above a few hundred RPM....and it needed starting fluid to start? Thought I may have made a mistake on the gear timing, pulled the front cover. Was correct, reinstalled the cover with another new crank shaft seal. No joy...still didn’t run correctly. I sent the assembly to NC Machinery in Anchorage and asked...tell me what I did wrong. Turned out the gasket between the governor and center section on the pump was the wrong one...didn’t have the oil supply hole for the governor. Reinstalled the pump..ran like poo wouldn’t carry a load and made oil. Turns out the pump guy at NC hadn’t pulled the barrels and plungers, and I may have got one of the plungers out of time on the rack?..sent the assembly back to Anchorage to Advanced diesel.. reinstalled... nice warm building still needed starting fluid to start. Rattles like hell, I believe the timing is to fast. The pipe plug for the 3/8” bolt into the flywheel is just inboard and below the turbo drain line. Insured I was on the compression stroke. Pulled the plug on the side of the injection pump and inserted a number 30 drill bit. Tightened the bolt on the pump gear...so...what am I doing wrong...is it sometimers on my part and I’m timing the pump wrong?
Are you certain you are timed to #1 TDC/compression. How did you verify?
A person holding his thumb on number one injector hole while I rotated the crank. Installed the 3/8” bolt in the flywheel. I haven’t used an dial indicator yet to find TDC on number one piston. If I remember correctly the flywheel bolts on one way.
Check the bushing on the injection pump idler gear in your front gear train. They are famous for wearing out, and yours has had plenty of hours to wear out. Also, are you rotating the engine at least 60 degrees in the direction of rotation when you are pin timing the injection pump? You have to do that in order to take the gear train slack out of the timing. Don't back up if you miss it, go on around again to pin time it correctly.