perkins Diesel

I am new to the forums here but have gotten some great advice. I am also new to repairing my own excavator. I have a 1986 Caterpillar with a Perkins T4.236 Diesel. The motor is hard to start and usually takes three tries. On the third try after I let off the key she will slowly start up, every once in a while i have to hit her with a little crack juice. Once she is running she runs smooth, but as soon as I start to put her in just a little bit of a bind she dies right down and sometimes cuts right off. Then she will fire back up on the third try and run again. I have changed all the fuel filters and my fuel pump. the machine had a rebuilt injector pump put on it before i purchased it. Somebody told me the injector pump was out of time. Any body out there familiar with these old perkapillar diesel motors that can point me in the right direction.

What Model Excavator?

The injector pump out of time could explain that pretty easily. Would you say the engine knocks more than an old diesel should? or less knock and more exhaust noise than combustion noise? Any black smoke when running, and/or when it dies?

It could still be a fuel starvation problem, and depending on who did the injector pump install, fuel is more likely than timing. If you can tee into the fuel supply line somewhere close to the injection pump, and run a line to a gauge in the cab, that will confirm that the fuel pressure is or isn't going down when it dies.

Or you could mess with the timing. It should have slots for the mounting holes on the injection pump, right? Are the bolts toward the middle of those slots, or all the way to one end? and are the nuts tight?

From your other post, did you solve the overheating by cleaning, or had you already tried the cleaning?

There is a little black smoke when running and a lot when it dies out. Motor has more of an exhaust noise than a motor knock once it gets going. I have great fuel pressure before the injector pump had a local mechanic check it and he said it was more than enough. When I bought the machine they had replaced the injection pump and when we got the machine delivered it was out of fuel. That was my first sign I was in for a long ride. We filled it up went to bleed it out and found the injection pump bolts weren't even tight, one of the bolts was missing and the fuel lines were loose. We fixed those issues and finally got her running and were able to unload her and I have had nothing but bad luck with her so far.
As far as the other post goes we did finally solved the overheating problem with the hydraulics we sprayed the cooler with coil cleaner for ac compressors it took resale paint of the coils and all the oil and dirt they had painted onto the coil. The coil cools a lot better now and air flow is great. I will never trust a Broker to help me buy a machine again that's for sure, if I can't sit my back side in it and run it for a while it an't coming to my house.

chewy5542 said:

the injection pump bolts weren't even tight, one of the bolts was missing and the fuel lines were loose.

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Well, that would certainly make one suspicious of the injection pump installer! The injection pump has slots that those bolts go in right? I'd start it up and turn the pump against the pressure and tighten one nut, and rev it a few times to see how it changes. Or you could look up how to time that pump the proper way.

Was the fuel pressure while the engine was dying down? or just while it was running with little load? If it had good pressure with no load then the transfer pump is probably good, but you could still have a restriction somewhere else that would keep the engine from having full power. That wouldn't explain the hard starting though.

As above. What model of Cat machine are we dealing with here..?