SOLVED: 3126B CAT motor wont start

fljlcw

Well-known member
Hello all Havent been on in awhile but now in need of your vast experience and expertise we were getting ready to move and the old freightliner would not start its a 2000 FL 60 with A 3126B cat motor have done all I and my mechanic buddy(which is 700 miles away) know to do short of calling cat and having it diagnost just hoping someone knows something cheap and simple before I do that tommorrow being today is A holiday Thanks in advance Fred P.S. if this is the wrong place to post this feel free to move it
 

Tombstonejim

Well-known member
Re: HELP 3126B wont start

Well 3126s are pretty simple all mechanical no fancy computers. But you did not say why it won't start. Does iturn over or just lay there/

If you are in south Dakato it must be cold. Is the block heater turned on and working? Is the manifold heater working?

Does it have enough battery power to turn fast or is it just barely turning over?

If You do not know or can't tell if the heater are working put an electric heater under the hood and try and heat the thing up, a hair dryer blowing right on the manifold for about 10 minutes might do it also.
 

scottyb

Well-known member
Re: HELP 3126B wont start

The fuel may be gelling from the cold if you last filled it in warm weather. Probably doesn't have the winter additives.
 

Hastey

Oklahoma Chapter Leaders
Re: HELP 3126B wont start

Give us more symptoms to go on. If she is heating up and rolling. Look for smoke. No smoke = no fuel. Like Scottyb said check for gelling.

If its just dead check for varmints. They like to build warm cozy nests in around wiring.
 

fljlcw

Well-known member
Re: HELP 3126B wont start

sorry guys yes it turns over plenty fast yes its plugged in and warm it will fire on either but wont run the fuel isnt gelled I am getting clean fuel no water out of water seporator it smokes out the exhaust when turning over havent seen any varmint nests and it is electronic and computerized it is A 3126B engine #8YL27480 hope this helps and thanks again Fred
 

GOTTOYS

Well-known member
Re: HELP - 3126B CAT motor wont start

Give it some ether in the intake while somebody cranks it..it'll fire up...Don
 

marvmarcy

Well-known member
Re: HELP - 3126B CAT motor wont start

If it won't stay running after firing with ether, it sounds like the injector pump isn't working or a clogged fuel filter, although it could also be a bad lift pump (if it has one). It seems to be fuel starved. You might post on www.rvnetwork.com (Escapees) in the mdt or hdt truck forum. Those guys really know diesel trucks, especially the hdt guys.
 

hoefler

Well-known member
Re: HELP - 3126B CAT motor wont start

May have air in the fuel system. On the secondary fuel filter housing, there is a primer pump. Turn it counter clockwise and give it a few good strokes. If you you feel no hard resistance, you have air in the system. Pull off the fuel filter and make sure it is full. Re-install it full of fuel. There is a bleeder on the fuel pump, crack it open and pump the primer until fuel flows from it. Close it and continue to pump it until you get good resistance. Then it should start and run, may be rough, but it will clear up and run smoothly. You may have to give it some throttle until it smooths out.
 

Niles

Well-known member
Re: HELP - 3126B CAT motor wont start

We have a 99 FL60 with the same motor. I would tend to agree it sounds like a fuel problem, if you have air in the system pump it till your arm falls off. Cats are the worst one to prime when they have air. I've drove trucks for 38years with cummins, cat and detroits in them, cummins and detroit are apiece of cake compared to a cat when it comes to getting them running. Checking to see if you have fuel in the filter first may save your arm, if it's not full fill it and then start pumping, leave the bleed plug open a little and when fuel runs out of it close it and pump some more, then try starting it again. Good luck
 

JanAndBill

Well-known member
Re: HELP - 3126B CAT motor wont start

Have you checked the oil and water, a low sensor reading on either will cause it to shut down once it starts. Also, have you checked to see if it has thrown any engine codes? Only an active code will flash. I think the fuel on that engine is controlled by the ECM. A faulty speed sensor or wiring to for example could cause it.
 

fljlcw

Well-known member
Re: HELP - 3126B CAT motor wont start

Ok fellers after trying all sugestions and pulling what little hair I had left out I finally had it toe\wed to cat, thank god for G.S. towing service. They determined it was the ECM or in english the computer, so after 2500.00 and A few more days we were going to be on the road and moving to Ft Morgan Colo. or so we thought the next morning we fired the old beast (freightliner) up hooked up and pulled out got several miles down the road and my volt goage started dropping oh well its just 250 more miles Ha several more miles and the good old allison trans. went to 4th gear and check trans light came on so after several phone calls while on the side of the interstate I finally got to the allison shop in Denver found out it was low voltage not letting the trans communicate with the engine funny seems our cars talk more to each other than people do so having the poor boy attitude I took one of my trusty little 2000 watt hondas tied it to the truck plugged in A 6 amp charger ive had forever and went to Ft morgan so now I will remove Alt and have it tested and rebuilt or replaced if need be and see what is around the next bend for us You gotta love life on the road sometimes just another adventure to mark down in my memory file I sure hope this is it for awhile and thank you guys for all your help and support Fred
 

scottyb

Well-known member
Re: HELP - 3126B CAT motor wont start

I mentioned this to our equipment manager yesterday. he said "computer". We have a couple of these engines in a dozer and a motor grader. I was going to report back but it seems like you already discovered the problem. Good luck in your travel..
 

oscar

Well-known member
Re: HELP - 3126B CAT motor wont start

Love the Honda solution. Great little generators.
 
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