Hello from New Zealand, Im having trouble with my CAT 303CR (Well under the yellow paint it appears to be a Japanese made Mitsubishi ) It cranks, cranks and crank for maybe 3-5 mins and eventually will start but this is very hard on the starter motor I have checked and cleaned the following Fuel Filter Fuel Water Seperator Air Filter Water Drain on Fuel Tank I thought it might be some air in the fuel line so I consulted the instruction manual which shows an air bled valve on the top left hand side of the injection pump. This was covered by a brass non tamer cap which I removed and exposed the bolt/lock nut combo shown in the picture below Completley removing this as per the instructions it actually appears that it is not a bleed valve.....as it is quite long with a smooth 1" long shaft. Also on cranking the engine no fuel comes out as it should My questions are :- 1. What infact was this bolt 2. What does it do 3. Any ideas as to what else to check for the hard starting The hard starting is only from cold, once the engine has been run it is no problem to fire The glo plug lights up and goes out as it should when the IGN is turned on Any help is very much apprecaited ! Regards Byron
That bolt might be a were you would put a injection timing pin tool to time the injection pump.The engine might have cold start solenoid for cold starting .Which gives more fuel for start up.Have you checked the glow plug for power .Evenknow the light comes on check them .I have see in the past were the glow plug hadso much carbon on them .That the carbon insulated them from full glow . Is this machine 12 or 24 volt?You can test the glow plugs with a battery for 12 volt system or two batteries in series for 24 volt .Put a heavy guage jumper wire from the center terminal on the glow plug to the positive terminal on the battery .Than take a jumper put it on the negative terminal of the battery and touch the nut part of the glow plug it shoud start to glow .Don't leave it their to long because the wire will get hot in you hand.Test all the glow plugs .
Check the Check Valve Remove Check Valve from the Fuel Filter Base. Inspect the Seal and the Back-up Ring for damage. Replace the seal and the back-up ring if they are damaged. Inspect the ball for damage. Check to see if the ball is seating correctly. Check the cavity in the fuel filter base. Ensure that there is no sharp edge that could cut the seal during assembly. Replace the Check Valve if the ball is damaged or if the ball is not seating correctly.
+1 on the glow plugs. They are almost certainly your problem going off your description.
Just A Thought I had a similar problem with a Massey 3090 Tractor with starting. Of course hard to identify the cause. Turned out the problem was the lift pump before the injector pump. It had a small internal leak, the filter was clogged to the high heavens with growth and a wonder it started or ran at all. I had just fixed the injector pump after some bad fuel and the motor ran well particularly when warm as it required less fuel and did not use much for its size. Turned out really difficult/near impossible to start even with the injectors bleeding fuel. Just not enough coming through and not enough lift pressure. Lift pump re-seal kit and problem solved!!!! Hope this helps if it is the problem you face. Dont know anything about glow plugs. Now I filter my fuel when putting in the tank no matter where it comes from (was reputable international supplier) and also add copious amounts of biocide. Have not had the problem since. Company paid for the fuel but the injector pump cost me more!!!! I know it was the fuel supplier as the jerry cans were new!!! Regards, MX45
Is there any fuel at the injectors? And how much fuel are you getting to the fuel pump? There is a pressure regulating valve in the filter housing. Check tha pic attatched. #'s 9, 13 and 15 in the pic is what you want to check. If you are getting good fuel to pump but not out...check the other pic. There is a solenod that has to be energized to allow the governor rack to spring back. If this solenoid is bad, not proper voltage to solenoid or the governor linkage hanging the fuel pump is not being turned on all the way at a slow idle. Of course if you are getting good fuel at injectors (meaning the fuel is shooting out 6" or more) then you could have low compression in cylinders. If after it starts it has alot of blow by, even with a perfectly functioning fuel system it will be hard to start. Hope this helps! Good luck!