I have a 06 303.5c excavator with 1600 hours. When starting the machine, it seems to take a long time"8 seconds or so" to crank. I have recently had work done on it. Had a fuel leak on the primer that was replaced and fuel lines were drained and cleaned. I was told that it had water and lots of trash in the lines. Everything works perfect now except for the crank time. Has a new battery, glow plugs are good. It does fire quicker after the first initial crank of the day, but still a little drug out. Mabey 3 to 4 seconds. Any ideas. I definately am not a diesel mechanic, but I am learning the hard way. Also this machine is new to me as I have had 2 bobcats and decided to go wt a low hor Cat this time
The fuel system would be something to revisit. You could be loosing prime while sitting over long periods. Before you crank the machine after it has been sitting a while, use the hand primer and give it a few dozen pumps before you start it. If it affects the starting, you have an air leak and loosing prime. If it does not do any check your starting circut. A few simple things to check would be battery, starter, alternator connections. You would be looking for loose connections and corrosion. If they check out move to battery voltage. A good battery should read 12.6 volts without a surface charge and some where between the high 13 and mid 14 while running.
I will check all of those. I am leaning toward fuel system. Ill be honest, im not sure where the primer is. I looked and found the fuel filter but no primer. I just got this machine so it has been more of a challenge than on my old machines. Thanks for your thoughts.
This machine might have an electric priming or transfer pump. I think it is located on top of the water separator housing. You should hear a consistent ticking noise with the key in the acc position. It should look something like a cylindrical black housing with housing with some wires running out of it
I did find that it has a electric priming pump. That being said, wouldnt that prime it every time and take the question out of the fuel system?
That is not always the case. If you jump in the machine and crank it a soon as you turn your key, it won't have time to bleed the system and it therefore has to bleed your system while you are cranking. Try leaving the key on in the acc position for 30 seconds or so and see if effects the cranking time. Low transfer pressure could also be culprit. Please check to see if your electrical side is preforming as it should before we dive any deeper.
One very common spot to get an air leak. Does your fuel filter still have the glass bowl screwed on the bottom? If it does, remove it and make sure there is an oring in between the filter and the bowl. A lot of guys lose that oring if it sticks to the old filter when swapping it out. They will suck air but seldom leak fuel. I have probably gone on 30+ field calls for just that.
Yep, what he said. ^ Also see if you what position you have to have to engage your glow plugs. That can help these small engines a lot when starting.
I tried starting the machine from cold and letting it sit for close to a minute to try and prime the fuel system, i didnt help any. So I am going to check out electrical before we go further, like you said.
Ok I have checked the battery. It is brand new and reading 12.4. I am getting 12.4 to the starter and alternator. Seems to be a good positive. All connections looked very clean, no corrosion. Also the fuel primer is definately pumping, I can hear it pumping and feels the vibration. So where would you go from here?. Thanks for all of the input thusfar!
I read a thread on this same exact problem on a identical machine. They mentioned a parisitic load, if i spelled that correct, on the hydraulics. I am unaware of any with mine. They also said that the viscocity of the fluid could make it hard to start. I have to say that the way the starter turns over is slower than i would think it should be, like it has a load against it? Any thoughts
12.4 volts does not qualify it as a good battery. Load test the battery with a carbon pile or a no fuel crank and the battery should not drop below 9.5 volts. A carbon pile will let you drag it down to half its cca which is the recommended procedure. A shortcut can be taken and you could use.a good known battery connected to you machine and see if it does make a difference. To get as far as a parasitic load we need to eliminate everything else. A cold engine will put more drag on a starter. Oil viscosity will not put an noticeable effect on starting unless you are running something completely ridiculous in a super cold climate. Pump is unloaded until you stroke a function. What is you machine s/n by the way ?
707's right. A "good" nominal 12V battery should make 12.7-12.75V when fully charged. The 12.4V you mention only equates to about 65-70% charged. It could be that your battery isn't strong enough in its present state of charge to spin the engine fast enough when cold to fire it up almost instantly. You are measuring the voltage without any electrical load, it could be it drops like a stone once you engage the starter.
So i charged the battery overnight and it gave the machine very little morr zip in starting. Still turns over slow and long time. I notice a strong smell of burned fuel when it does start. How do i begin to look for a air leak in fuel system? Also to check the primer pump, how should i go about that? I have also read that the auto idol switch can give probs on this machine. Think that could cause starting probs, it seems to work fine.
One of our 303.5c's was having issues with notable slower cranking than the others. I found a voltage drop at the starter. I diagnosed it as a bad ground but never tracked down why. I ended up adding a extra ground strap between the engine block and frame which seemed to solve the problem.
G'day, similar problem different machine. Everything looked good and tested OK but when I went to crank all sorts of issues. Problem turned out to be a battery clamp that was finely split and you just could not see it - no corrosion - just a fine line but enough for the tightness in the nut holding the clamp not to be reflected in the clamping of the battery clamp on to the battery terminal. Hence when under the stress of the starting cycle broke down in current transfer ability. Hope this makes sense. I would double and triple check the clamps by taking them off and prying them with a screwdriver or the like to see if anything opens up a little. Can cause the big problems. All the best - MX45.
So today i took some jumper cables and grounded the engine to the frame and bingo, the starter zipped like it should. I am going to add a ground and i will be in business.Thank you so much for the help!
Glad that was it. :thumbsup