How are big rig Diesels so easy to start? - PeachParts Mercedes-Benz Forum

Meta6981 · #1 01-04-2006, 06:19 PM

Well i don't really know how my car would handle snowey conditions because i live in california where it was like 60-70 degrees today. But my car really does not like sitting for more than a day. It is a pain to start once the sun goes down after sitting for a day. likes to start then stall out, then start again and idle till i go to shift from reverse to drive. But on the 82' foot cutter. that was a pain in the arse to light off. It would take about half a can of ether to light off. then it would smoke for about 20 minates if idleing less if we left immidiatly. but once they fired it was the wake up call for the boat man. Dual V-12 cummins. Ahh good times, good times

R Leo · #2 01-04-2006, 07:32 PM

Most industrial engines (Cat, DD, Cummins etc) are direct injection. DI engines are significantly lower compression (16:1 or 17:1) than the 61X and 60X engines we know and love. The lower compression means they spin fast and make enough heat where it is needed. In addition, the fuel getting injected directly into the combustion chamber generally means nothing else is needed for starting. In severe situations, a shot of manufacturer-approved starting fluid is typically enough to get them going.

My JD2040 (1978 Mannheim-built, 40hp, 3cyl, DI) cranks and fires off as easy at 20°F as it does at 100°F. In addition, the battery looks like one you'd find in a Camry...there's not enough room for anything bigger. For the really cold days, this tractor has a special port just below the steering wheel that is used to squirt starting fluid into the intake tract from a proprietary Deere container. I've neve neede this and, if it is that cold, I'm either going to stay inside or go borrow my neighbor's tractor that has a cab.

The ancient 4-35 Jimmy that powered our bay shrimper had no glow plugs either. In cold weather (40° or so was the coldest we hever went out in) you simply hit the switch and cranked until it started...sometimes it would take 30-60 seconds if slow grind to finally burp to life, belching huge clouds of blue smoke out the stack until it warmed up.

boneheaddoctor · #3 01-04-2006, 09:17 PM

My W123 hits instantly with never more than a 30 second glow....and that being sometimes in below freezing temps.....if it takes a lot of effort you need to find out why....either have a glow plug or more bad or maladjusted valves or low compression......

And example is my parts car that I got off DCulkin last winter started on jumper cables (battery would not hold a charge at all) in 10 degree F temps on the third revolution after a single glow cycle...This car was dragged out of a field the previous day where it sat in mud up to it rocker panels for the previous two years....it ran smooth and didn't even smoke....(had two year old diesel in it.)

Matt L · #4 01-04-2006, 09:35 PM

I'd check the glow plugs first, then the valves. That rules out the easiest and most likely things. Assuming, of course, that the starter turns the engine just fine.

JimmyL · #5 01-04-2006, 09:50 PM

It's funny. All this talk of compression, and I can't get my starter to move in cold weather. I think somebody mentioned sticky solenoid, possibly from cold grease, but I haven't investigated at this point.....
I can't imagine the cold would have anything to do with electrical connections....

kerry · #6 01-04-2006, 10:13 PM

Quote:

Originally Posted by JimmyL

It's funny. All this talk of compression, and I can't get my starter to move in cold weather. I think somebody mentioned sticky solenoid, possibly from cold grease, but I haven't investigated at this point.....
I can't imagine the cold would have anything to do with electrical connections....

Mine used to do the same thing. Procrastination paid off. The problem has completely gone away of its own accord.

t walgamuth · #7 01-04-2006, 11:36 PM

weather increases resistance in electrical things. so if you have any weak links the lessened power of the battery will not be enough to start the car. you can baby it by with problems til it gets really hot or cold, then the weak link will bring it down.

i once had an old cummins 166 powered 66 reo cab over 18' stake truck that i bought when i was building my house. it had two batterys the size of a small dog house. no glows. it once sat for about six months. when i started it i just ground the starter for about a minute and a half. it just kept cranking and slowly went a little faster til it finally started. i thought for sure it wouldnt but it always did, no matter how long it sat.

i love diesels!

tom w

barkford · #8 01-06-2006, 10:22 PM

Used to drive an International powered school bus. No glow plugs. Just hold that starter on until she turned over. Granted, you wouldn't want to be standing behind the bus during said event.
TDI - supposedly GPs are firing on new ones as soon as you open driver's door - thus the short wait before actually cranking. I think the new CDI is now also firing GPs as soon as drivers' door is open. In any case, the wait is short.

t walgamuth · #9 01-07-2006, 12:26 AM

are you sure about the germans not having diesels?

i could have sworn i read that they were.

or maybe it was from kelly's heros movie. and maybe the tank had been converted after the war.

i thought that they had a method of running diesels on coal dust suspended in water or such.

tom w