Caterpillar C9 Won't Start

[LloydW]

I just replaced the two chassis batteries in my 2005 Beaver.

The engine turns over fine but wont fire.I am sure I reconnected the battery cables correctly.

Suggestions please.

[kaypsmith]

Be sure to check all fuses, the last time I had that to happen, the fuse to the ECM was blown, of course no ecm no go on the diesel.

[michaelhillhouse]

Better hope it's the fuse and not the ECM itself. I lost the ECM on my Cat when I changed the Batteries and touched the wrong wire.

[LloydW]

Thx for the information guys.I checked the ecm fuses all good. I also checked power to the ecm fuse block also good.

I am sitting in Mazatlan Mexico so resources are limited.

Any more suggestions/comments are appreciated.

[wildebill308]

I would also look at the fuel shut off solenoid.

Bill

[jleamont]

Check your engine oil level, make sure it is full or close to it. While cranking it over...is it spinning fast or slower than normal? What was the reason for the battery change?

[obedb]

I lost an ECM on a series 60 once. No instrument lights at all. The engine turned over willingly but no fire. If memory serves it was close to $2000 plus the tow bill and labor. A Cat might cost more. If the fuses are good but you have no warning lights on the panel that could be it. Mine failed enroute.    Good Luck.  Hope it is something simple.

[DaveAtherton]

Lloyd,

First question does your fuel filter have a hand primer pump? If it does see if it is hard to push in-- is should be. If soft/easy to push, there is air in the system.

If answer is yes "it is hard to push", than open up engine cover under bed and go to rear of engine (foot of bed/toward front of coach). There is a hex fitting about 3 inches long on elbow coming off rear of cylinder head at 45 degree facing passenger side of motorhome. There is a hose connected to this hex fitting. The hex fitting is the fuel pressure regulator that holds diesel fuel in cylinder head. The fuel pressure regulator has a check valve and diesel fuel fines if setting will stick the check valve.

Remove hose connected to the regulator and turn engine over to see if fuel comes out and in most cases engine will start. The hose that I am talking is the return fuel hose going back to fuel tank in front.

We need to know for sure that when turning engine over by key that diesel fuel passes out the back of engine head. Note: if fuel does not come out of check valve engine will not start.

This is very common problem with Diesel fuel fines ( not using Cat OR-0751 2 micron fuel filter and/or fuel filter needs replaced).

Last: bad diesel fuel. Have chased down no start but engine turns over as a electrical problem and has ended up with fuel pressure regulator on rear of cylinder head. Might look this area over real good.

Dave Atherton Retired Cat Mechanic

 

[LloydW]

Thx Dave.

I have just changed the filter and they looked good. Will now check pressure regulator.

[wolfe10]

Lloyd,

As Dave asked, do you have a Caterpillar manual primer pump? And, if so have you tried pumping it?

And to pump it, unscrew (counter clockwise) the knurl nut. Then pump in/out.  If easy you have air in the system.  It will go from very easy to VERY hard to pump all of a sudden as fuel is non-compressible. Be sure to push the knurl nut all the way in and screw it in clockwise when you are finished or you will have a fuel leak.

[obedb]

Dave or Brett/ Is there a similar regulator/check valve assembly on a 2003 Cat 3126E. Have not observed the primer pump on ours. Very familiar with them on 3406E and C-15s. Cat even prefers the filter be installed empty and primed with the pump. Been there done that. Up to fifty strokes. Just curious for future reference.

[jleamont]

Obedb, some have it and others don't. If its there it would be on top or just next to the fuel filter on the engine. The last two I can recall looking at in a RV were not equipped.

[obedb]

Joe/ I know that you have worked on Cats. Primer pump/ easily recognized. The rear facing regulator is not familiar to me. The return line on the 60 comes out the back. Probably the same on all diesels.

[wolfe10]

http://www.ebay.com/bhp/caterpillar-fuel-pump

[jleamont]

Obed, here is a photo of where they typically are located. Pointed at the camera is the knob.

[obedb]

The primer pump is a familiar item to me. I have run a lot of big yellow engines. My question  about the check valve/return line coming out of the back. No experience with one because probably no trouble with one. Last rig had a hand operated check valve that had to closed before changing primary and secondary on a series 60. Next time I visit our Phaeton , I will have to move the bed, and take a look at the return setup. Should know in the event of a problem.

[jleamont]

If you head this way for Pot Roast bring the coach and stop by or I can come over and point it out to you. Got you thinking about pot roast huh?

[Corona4me]

ECM...sorry, but they have a habit of dying with the batteries. I hope I'm wrong!

[manholt]

I would suspect that if the ECM goes, so does the fuse? Or not.

[LloydW]

THANKS EVERYONE FOR THEIR TIPS AND SUGGESTIONS. I HAD MATCO CATERPILLAR FROM MAZATLAN DIAGNOSE AND REPAIR MY UNIT. TURNED OUT TO BE A GROUND WIRE FROM THE ECM . EXCELLENT SERVICE,VERY PROFESSIONAL. THANKS AGAIN|| 

LLOYD

[kaypsmith]

Thanks for updating us, this can help for future references.

[jleamont]

Glad you are all fixed up!

[manholt]

Good show. Now you can get back to vacation or whatever, with peace of mind.

[obedb]

Who was closest to the possible problem? When your ECM fails, the engine turns over but there are few if any warning lights that go through the start cycle. In my case there were none and I am guessing that is probably the norm. Luckily the OP after a lot of worry, found a tech in Mexico that identified a bad ground. Battery change/who knows?  The easiest observable symptom would be no warning lights. Just a thought!