Go BottomL3450 Won t start
 | Troyl
Join Date: Posts: 1 
|
2002-09-18 42595
I have an L 3450 it starts fine when it is cold but lately when you shut it off after it is worm it won't start just turns over. For alittle while now you would have to turn it over a little while then it would start. But now it won't start at all I know it's not the shut off valve becous the only way you can get it started now is by putting a rag near the intake with gasoline on it so the fumes go in and it will start. Once started it runs fine any ideas? Oh I just changed the fuel filter thinking that might be it but I still have the problem
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley 
|
2002-09-19 42628
I'm out of time this morning but will get back to this. In the meantime maybe there'll be replies that are more helpful than anything I'd come up with. ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
 | Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
 Pics
|
2002-09-19 42629
First I would start looking for any fuel leaks. Check all the lines as they go to and from the pump to the injectors. Do you have a lack of power when running? ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| Troyl
Join Date: Posts: 1
|
2002-09-19 42662
No lack of power when running. ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
 | jeff r
Join Date: Jul 2003 Posts: 428 burton. michigan
Pics
|
2002-09-19 42664
I'd look at plugged injector nozzles first and then injector pump pressure. How many hours on this tractor? ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-09-20 42685
I'm wondering if it always starts and runs OK and then won't start after shutdown or whether there's some variation to the pattern?
For example, once it starts will it run OK in a long hard run of several hours? If it starts, will it start again if it's shut down after only a short idle? How long does it have to sit before it will start again?
Exhaust smoke often tells what's going on with a diesel. Is there appreciable exhaust smoke and if so, when and what colour?
Full of questions I know, but maybe the answers will trigger somebody to figure what's going on with the engine. The question 'how many hours' is important to be able to guess if the problem is low compression. A guess a companion question is when the valves were set?
....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| Troyl
Join Date: Posts: 1
|
2002-09-20 42707
To answer all of your questions, the tractor has 1000 hrs on it nothing has ever been done to the engine injector pump rack or anything else ect. When cold I can start it 10 times in a row and it starts every time. When it's hot I just have a problem getting it started once it is started hot runs great strong hr after hr no problem When it is hot it has to cool down a couple of hr's befor it will start unless I put some gas fumes to it. We are going to run a compression test on it I will let you know how it turns out. Troy
....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-09-21 42717
Dang! Too bad it's a diesel. The description is almost identical to the doggy coil problem on old Ford gas engines. At least that's a simple one.
You'd expect compression to be fine on a normal 1000-hour diesel. I was thinking that maybe if it had marginal compression then oil thinned during operation and there wasn't enough compression to start it until the oil thickened. That doesn't seem like a good possibility.
The fact that it seems to run OK indefinitely sort of eliminates fuel starvation problems from things like a filter screen inside the tank, line obstructions etc. Air in the lines at start up on my Ford makes the engine run and missing for a few seconds before it dies and it puts out gray exhaust smoke.
Diesels are sort of funny things. They actually are pretty simple. Happy engines run clean. Unhappy ones usually smoke in some way. All it normally takes to make a happy diesel is air, fuel and compression. I wonder what's missing here?
Another question: I wonder if it will start if tried immediately after shutting down or if the problem happens only if it's shut down for a short while. I guess that as long as I'm making questions rather than answers, I might as well wonder if the use of pre-heat makes any difference to the stating problem?
If nothing obvious pops up, I might start wondering if there's something about the starting system that goes gimpy when it gets hot? If so, it might not spin the engine fast enough to start it.
Anyway, there are probably no solutions here but maybe some of the idea will trigger some thinking that will lead to the problem.
....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
Pics
|
2002-09-21 42718
With the the fuel filter being replaced recently, we often do it twice. I would loosen the fuel line coming from the tank to see if you have a good flow of fuel. If you do than the next place to go is the injection pump. The rotary style pump is not the most reliable we have seen in this industry as much as it is widely used. ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| Troyl
Join Date: Posts: 1
|
2002-09-21 42749
I was told by a few people latly my brother included who is an diesel mech on PGT big trucks that it is possible that since the lifters have never been adj. that when they get worn that they will actually hold the exhost valve open a little bit when hot making it hard to start we will check that out also. ....
Reply to |
Quote Reply |
Add PhotoL3450 Won t start
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-09-22 42764
Troy: I was thinking along those lines when I asked about the valve settings. After I posted I remember realizing that I actually can't remember if cold clearances are wider than hot ones--it's been quite a few years since I've had to know details like that. I do recall though that if exhaust valves are too tight they might burn. Tight valves spend less time in their seats, which is the main way valve heads dissipate heat.
Setting the valves would be a nice simple fix, and it would be good if that's the answer. I guess the mechanism would be that the clearances are marginal, and an engine gets hotter for a awhile after it's shut down. The clearances completely disappear and the valves don’t seat until the engine cools a bit. If that's the explanation, I wonder if giving the engine a 5-minute cool-down at slow idle makes any difference?
Anyway, valve clearance is a possible explanation and easy enough to check out, but I wouldn't forget about the ideas Art mentioned either.
If it turns out to be valve settings, I might carry through with a compression test because it's possible the valve heads became overheated and the compression might be low..
....
Reply to |
Quote Reply |
Add Photo
Go Top
Share This