Our cat c4.4 won’t start until we give it some sniff and then it starts no problem and runs no problem, any help would be appreciated
Serial Number.? How many hours on it and what's it installed in.? Got any photos of the installation.? (You'll need to make at least 3 posts before you can upload photos) First & most important question - Is the air filter maintenance up to scratch.? If it's anything like the C4.4s we had in compactors it probably needs (in order of price) a rail pressure relief valve, injectors, or a high-pressure fuel pump. If the cheapest doesn't solve the problem then you move to the next expensive, etc, etc. TBH the best way of diagnosing, if you don't want to simply shotgun a load of expensive parts at it, is to get Cat ET hooked up to it and start looking at the pressure in the fuel rail.
Serial number 44423353 and it’s installed in a mcluskey s190 screen with 7596 hours and has recently been serviced but it has always been hard to start for over a year now
Does it smoke at all, either during starting or when it’s pulling a heavy load.? The problem with engines in screens is that they tend to operate most of the time buried in spillage, and if the air filters are not serviced regularly the engine will get dusted PDQ. TBH with 8k hours on it in that type of application it’s probably close to being worn out, but hooking ET up to it would at least enable the fuel system troubleshooting to be done. Post some photos showing the installation and the general condition of the engine.
I don't know about this engine but lots of small Cat motors are rebranded units from other manufacturers. The hard starting issues I saw a lot of involved the automatic sensing for the pre-heaters. Many of those small engines won't start without the pre-heat and the control modules won't turn on unless ambient temperature is below a certain point. Lots of clients started using ether to get them started on 50 degree F. days and they then started the climb into needing more of the cocaine as time went on. I've had a couple of clients put in a manual button to work the pre-heaters which solved the issue.
No grid intake heater on this engine John, but it does have glow plugs........... The weird thing is that apparently the glow plugs are controlled by a relay but the full electrical schematic doesn't show it, only the abridged schematic in the Troubleshooting Manual.
Have had a few issues with the 6.6 that i believe is very the same. Check injector leak off. Had one that ran great once started. It fairly simple to do, if you need procedure i can get it for you when i get a chance.
Try looking at this also from this angle; at the crank speed (200 - 250 RPM) the engine is not self-sufficient. On idle it is. So it could be as simple as not being able to draw fuel from the tank...
Plenty fuel getting there, it seems to be starting a lot better at the moment who knows what has changed, will monitor and see what happens thanks again for all your help
Don't mean to revive an old thread but could you possibly explain the procedure?
You remove the return line and crank the machine for a given amount of time, measure the leaked fuel volume and if it is over a certain amount, you have one or more injectors that have high pressure leak off causing your no-start problem. Essentially the rail pressure can’t get high enough. Ether allows the engine to spin faster which causes the pump to put out the volume of fuel required to overcome the leak.
Thank you very much, it would be hard pressed for cat to give me the information and specs on fuel volume and crank time, or would they be the ones to ask?
Post a machine Serial Number. Let's see what pops up.
Www00612 is serial for d5k dozer can provide engine serial if needed but will have to do some digging since I'm not at the machine right now. I appreciate all yalls help.
Here you go. Maybe @ahart can give you some practical "tricks & traps" guidance regarding performing the procedure.
I sure do appreciate all the help sir, on the road now will go through the files when I get home.
Honestly I don’t think I’ve ever been lucky enough to get to do the leak off test on a dozer, I’ve always had to do it on an excavator where you’re standing on your head. If you do find that the leakage is beyond spec, I personally wouldn’t worry about which one is causing it, being a 4cyl, I’d just change them all.
Yes sir I will, do I need the cat test kit or can I just use my fuel pressure test kit and use the fitting in it to plumb a line to a container? I don't see why the cat part would be necessary but I am curious.
How many hours on the engine.? Maybe it's ready for a set of new squirters. Only thing I would say is don't go installing a set without installing a replacement rail pressure relief valve as well. In fact from experience I'd throw a valve at it first and see what effect that has.
Right around 5200 I already have the relief valve ordered and planned to change the valve before I do the pressure test. I'm betting on the Injectors but wanting to verify before I change, not thinking I jection pump because once the machine starts off of ether it runs like a top.
Really the only thing you need is the modified banjo fitting that has a nipple to attach a hose to so you can collect the returned fuel for measuring.
Awesome I will let yall know results when I get it going I can't thank yall enough.
Did the test today. Results were as figured. Setup the banjo on the return bolt and started cranking, within 15 second the machine had succeeded the 28ml and was well on the way to 40. Any input is appreciated, I have injectors in the way. Decided to replace all four.
You’re on the right path, change the injectors out and it should be happy again. You might check the fuel transfer pump while you’re right there with it and make sure it’s putting out a heavy volume of fuel, they have a tendency of getting lazy on those Perkins engines.
Appreciate it sir thank ypu for the abundance of knowledge I guess last mechanic changed it so it's brand new, outting out plenty of psi. Hooked scanner to it and it wouldn't build over 1400 rail at 350 rpms, only been wrenching since I was 15, 17 now really the first I've dealt with any common rail engines excepting cummins, I appreciate all yalls knowledge and want to thank yall for all the help.
There’s an incredible amount of experience here across a broad range of products. Most folks here are very happy to help and like seeing people succeed.
Got injectors in just waiting on feed tubes/injection lines. Another question does anyone have torque specs on injector hold down bolts, Rocker assembly, and possibly feed tube lines?
239 in lb on the hold down bolt 22 lb ft on the fuel lines 26 lb ft on the rocker shaft
Thanks sir your a lifesaver.
Did you replace tha injector hold-down bolts with new.? They are supposed to be single use only.