hard starting diesels

[spencerhenry]

i have an 05 mustang 2109 with a 115hp perkins. just under 1100 hours. when it is warm it starts great, but not when cold. it doesnt have glowplugs or an intake heater. i am not a novice mechanic, but am not sure what can cause a diesel to start hard. i am looking for suggestions from someone who has experience with this type of situation.

the perkins in my skidder starts much better, but it is from the 70's non-turbo, and when it is below 0 with no block heater a quick shot of ether and it is going. my 98 franklin with a cummins also starts very hard, it too has no block heater, or intake heater. but my 4045t john deere starts down to about 0 without no difficulty, colder that it cranks for a bit, it too has no glow plugs or intake heater.

[Gary_C]

It could be problems with the starter/battery. Diesels first have to turn over fast enough or they will not start. So that is the first place to look.

Next thing would be valve problems, although you should not be having valve problems with that few hours. Check for blow back in the intake manifold.

Then it could be injection pump problems or injector problems. Check the pump timing. You should be able to find out the settings in your operators manual.

Just a few easy things to check.

[Splinter]

Around here the old skidders are warmed up by exchanging coolant with their pickups.
Don't know all the details, but there are quick disconnects in the truck heater core loop, and somewhere on the skidder.

Have heard that it can cause problems in the truck by shock cooling, BUT seems unlikely to me if the QD's are kept in the heater loop, a lot less flow there than in the radiator loop.

[woodmills1]

did it come equipped with a plug in block warmer?

[spencerhenry]

i am not wondering how to get it warm before i start it, thats easy.

it has 2 new 700 amp batteries, cables appear to be good. it cranks fast enough i think, at least not different warm vs cold. it doesnt have a mechanical injection pump, or at least it doesnt appear to. looks to be all electronic. i wonder about valve timing, and or valve lash. never run the valves on a diesel, but like you say, shouldnt need to with 1100 hrs.
any more ideas?

[woodmills1]

diesles with out glow plug usually provide a plug in to electricity to warm them so they start

[spencerhenry]

electric block heaters are not much good at 10 below 0 and 5 miles from the nearest outlet. not much logging i have done is near power lines much less an electrical service.

[Dave Shepard]

The Perkins on the mill and edger didn't want to start at all yesterday either, and it wasn't even cold yet. I know a lot of guys with these small perkins engines in ASV's, chippers, etc., all cold blooded.


Dave

[woodmills1]

just askin a question so guess I can't answer yours

[zopi]

If you have a little generator or inverter for the truck you could improvise an intake heater with a heat gun and extension cord...iffit's that important.

[Cedarman]

Our L785 NH skid steer was getting hard to start after setting all weekend.  This happened several times.  Found a tiny pin hole leak on the rubber infeed line that was letting a very small amount of air into the fuel.  Replaced the rubber lines and no more starting problem.

Spencerhenry, most likely not your problem, but just something else that can bite the rear and needs to be aware of.

[olyman]

spencer--on some perkins--you had to open the throttle wide open---then on top of the injection pump---there was a button you pushed in--it gave max fuel so it would start right up--and as soon as it started--you throttled it back------dont know if yours is like that or not. Also, you could rig up ether injection--or build a glow plug heating assembly. And some of the newer off road diesels have a aneroid on the back of the injection pumps. If yours has one, good luck. These limit the amount of fuel the engine gets until the blower starts to produce boost. Which it wont till you throttle up, and make it start to pull. Which aint happening on a cold start. And yes, a good injection pump shop can bypass this. Epa mandated to cut fuel consumption---just love them clowns-------------------------------------------------

[underdog]

Low compression will also cause cold start problems.
You end up having to crank it long enough to get some heat in the cylinders.
I learned this with a worn out detroit in a road tractor, and my backhoe is starting to show its age.

[Gary_C]

You could still have valve problems even with that many hours. Check the compression against specs.

[logwalker]

I am going with the air leak in the infeed to the pump. I have a cummins that does this when it has been sitting for a while.

When it is running put a hose on the return line and run it into a jar and look for bubbles. Air leaks can be a real difficult thing to find. Sometimes it is the pickup that is blocked and creates suction in the lines. Plugged filters can cause it also. Does it run at full throttle for extended periods with out losing power?

Joe

[rebocardo]

I know what the Perkins is, I do not know what your equipment is.

My experience has been with getting 300-400 tractors (class 7/8) to start in 0-32F weather in NH at least once a month on a used truck lot.

If your batteries and cables are good, I would look at the fuel filter. Reason being is the water that collects in a tank, mixed with diesel, in cold weather can turn to a sludgy wax that blocks the filter and you simply do not get the flow you need. Even if it is flowing. Using an additive helps.

> but am not sure what can cause a diesel to start hard

Colder air intake means the compressed air/fuel will not ignite because the flash threshold has not been met for that compressed volume. Especially if the engine is slow in cranking. Spraying ether in is just mixing something extremely volatile into the compression that will ignite under almost any circumstance.

Some engines, especially commercial ones, that are stuck into a variety of applications, are not designed from the get go for exterior use, they require supplemental procedures.

If it will not start even with ether, then check the fuel filter. Just because it does not look clogged, does not mean it is not partly clogged.

As someone else mentioned, look for a pinhole leak. Bubbles anywhere are always a good indication.

Now, what you can try that is fairly cheap is to give the battery a boost as you are trying to start the diesel. That might give it enough power to quickly turn over to create the heat/compression needed to start the engine.

If using a truck, do not run it, you can damage alternators if they fight with each other, especially on a Chevy, it will blow the fusible links. Just use the truck as an extra, warm battery.

[stonebroke]

double or triple aught battery cables make a world of difference in cranking speed.

Stonebroke

[Dale Hatfield]

I would check for air leaks in fuel lines.
Check for a shut down solenoid  open when ya turn it off closed by electric magnet when ya turn the key. If it is getting weak  or slow to pull up then  they can be a bugger to start .
Check water separator.  Then have pump timing checked, As  advanced timing  can  cause hard starts .
Start simple before you go in deep

[truckwrench]

We run a bunch of little cummins they start pretty good ,the older Perkins were great for cold starts ,JD's depends on which pump the ones that start with full fuel can be real hard. The newer diesels have problems because of emissions they all start hard and the new fuel does not help we run lucas fuel conditioner seems to help some I change some fuel and timing settings sometimes helps sometimes not so much.

[truckwrench]

Altitude also causes alot of problems that nobody can explain.  :-\

[Cedarman]

My WAG is that higher altitude means the air is less dense, so when the piston goes up there is less compression.

[truckwrench]

The newer engines have a altitude compensator,but they seldom work over 5000 ft. Can really bug me nuts to find it and do away with it,sometimes I can change the timing enough to to get by.

[arojay]

I would check all of the things that Gary C said in the first reply.  I sometimes run a little Cat 426 hoe for a friend and it is Perkins powered.  It is very hard to start in cold weather if not preheated.  With 0w40 synthetic oil and no preheat ether must be used  if the temperature is a little below freezing. Overnight temps here have been around 0F/-18C recently and I have been preheating my JD's.  I use coolant exchange from my pick-up and the 0w40 oil and the ease of starting can't be beat.  Cold cranking is for the birds.  Lots of guys use diesel fired preheaters too.

[John Woodworth]

How much Either has been through it, over use of Either rounds the top edge of the compression rings eventualy making them dependant on it to start cold, it can also break the compression rings in extreem situations.