Hey, I put a used 4JB1 engine in my ihi 55j2 excavator a while back. It runs well and does the job. I'm struggling to solve the occasional starter woes. I've tried 2 new starters in it off amazon. Usually it will crank just fine cold. Occasionally when restarting it when warm the starter just clunks and doesn't crank. Get the trusty mallet out and tap the starter while turning the key and it fires right up. I'm at my wits end, don't know what could be causing this on multiple different starters. Any advice much appreciated. John
The japanese like to put lots of safety relays on the starter. I'd hook up some test leads and see if the starter solenoid is getting power to the small terminals when it's hot the same as when it's cold, or if some part of the starter circuit has a relay that is not working when hot.
Had a Deere 50D that would barely roll over during starting. Cleaned all the battery terminals, checked relays, voltage… the basics. After a few hours I discovered the negative battery terminals had very high resistance and was choking the starter ability to draw enough power from the battery. The negative cable felt almost hot after 10 seconds of cranking. When trying to figure out any engine starter issues, I always add cable condition to my checklist. *the bendix could be dirty, the solenoid coil could be weak, the solenoid wire from to the windings could also be failing. Lots of things.
There are some safety relays but the starter solenoid is definitely getting power since I can hear a 'clunk' from the starter. Tapping with a hammer while turning the key has always fixed the problem. I think it has to do with the starter, the starter's power source, or maybe how the starter is interacting with the flywheel? I'll do some thorough checking on the wiring. I know the battery negative cable immediately gets bolted to the battery tray box, so the machine is just grounded through the frame. Maybe the battery tray welds are giving up, or there's high resistance somewhere else. I'll try to feel around for what's getting hot, that seems like a good strategy.
Had similar problems. Solution was adding a heavy guage ground conductor to the starter case,and connecting all grounds physically together, i.e. engine,battery, and starter.
If the ground cable is burnt off internally, with only a few strands left, solenoid may go but no start. Need to voltage drop test from battery to starter on positive and negative side. Some are un aware that a cable with 1 strand good from 1 end to another will ohm test perfectly but start nothing. A good Digital volt meter can find problem quite fast. Any questiuons, here to help. Simon C
Hi John, I send you Service Manual for ISUZU Engine 4JB1 . Check Starter , and Solenoid. Regards
Lots of equipment has the battery negative going directly to chassis or frame. There is an additional cable that is between chassis and engine, that’s often overlooked. I agree, a cable directly from battery to engine is ideal. Solenoid tapping works, for awhile. Until you stall in a bad spot and need to fire up quickly again… then tapping the starter is a nerve wracking experience. Be safe, happy Turkey day!
Hey did you ever figure out your issue? I have an IHI 35J that has pretty much the same issue. Isuzu 3LD1 engine. Haven’t tried tapping it yet while starting but whenever it gets warm after operating it a while, it just quits starting! You can hear the solenoid clink but doesn’t turn over at all.
I ended up running new starter cables, positive and negative cables. I also ran a negative cable all the way from the battery to the starter, instead of just relying on grounding through the machine body. Haven’t had issues since. I think the old cables had corrosion, and were occasionally causing very high resistance.
Just found your solution to your problem. It was exactly as I stated in post #6 above. Glad you got it figured out. I have seen it too many times to mention. I start most repairs on start syatems by checking all the cables under load for voltage loss. Good to also test Alternators occasionally for AC leakage from the diodes. I have told a few how to do and it gives a very good idea about condition of alternator. Simon C