Cat 3126 B won't start ****HELP***

You need to perfrom a an injector soleniod test when the engine is cold, so you need a laptop with Cat et. Sounds like you have worn intensifier pistons, this will causes the injector not to fire cold but will come to live when the engine warms up. The only way to diagnose is with a laptop and start the engine cold.

Injector seals will cause oil to leak from the high pressure rail in to the crankcase. This will cause a hard starting problem cold but usually a no start condition hot, also will log 164-11 actuation fault.

 

Hi Jcross,

I was looking at the injectors myself but without ET this is getting quite expensive. I am thinking to replace all the sensors in the system along with the injectors and heater. Good luck with your injector seal replacement. I will be waiting to hear of your progress.

 

DDS,
That is my problem. I do not have access to ET at the moment.

 

having a problem with my truck, in cold fires up with no problem, but when engine is hot it cranks fine but will not start, as if it had no oil. cat 3126 standard trans with 300k. what could be the problem? but when it's pushed started will start fine.

 

Those engines use high pressure oil to actuate the fuel injectors. No start when hot is usually the oil is leaking past something because the oil is thinner. Could be injector orings, bad high pressure pump or bad injection control regulator. Chances are the reason it starts when the truck is pushed is because the engine is simply turning over faster than when cranking and the oil can build up enough to start the engine. Shouldn't be too bad to diagnose. If it has been years since the injectors have seen new orings, that would be a good place to start.

 

Thank you for your help that's where I'll start

 

Hi,
I have the same problem with my cat 3126 engine. Does anyone know where I can order the speed sensors from? Or would you have the part number?
Thank you!

 

You would order those from Cat. Give them your engine serial number when you call.

 

Thanks, Heavyd.

 

netoglick (guys),

you can get them from CAT. If you are still having problems I can get you the part numbers. I eventually changed my timing sensors, IAP sensor, fuel transfer pump, fuel pressure regulator, air temperature sensor. I bought the high pressure oil pump but did not install it. CAT technicians came with ET in the beginning. They were the ones who replaced the sensor and left. The problem remained. I continued to start it with starting aids while changing the other parts I mentioned. After changing all those parts CAT Tech came again with ET. The injectors all checked out. There were some codes that came up 164-11 (injection actuation pressure system fault - 39), 247-11 (brake pedal switch #2 fault and switch #1 fault), 84-1 (Vehicle loss of signal - 31), 105-3 (intake manifold air temp voltage high - 38). They left and were to get back to me with instructions to solve the problem. I went on my own and bought some new injectors and installed them. The truck started immediately and has been doing so since. Working perfectly. I still have a new spare high pressure oil pump.

So you may need to change your injectors or at least the o-rings after you have exhausted the cheaper options.

Regards,