LX 485 Cold Starting Problems

[Mike10]

Your kidding me, right? Here...watch some of these: http://www.youtube.com/watch?v=trEaaoktcs0 http://www.youtube.com/watch?v=X7dAPNZD3t4 http://www.youtube.com/watch?v=sk5IPReMEs0

Interesting videos, but, whatever piece of equipment or vehicle you are testing go by the service manual for the correct specs for the glow plugs used in that equipment or vehicle. In the two videos that I watched both would not pass the specs for this Lx485.

 

[Cobra-R]

Well you are both right and wrong. You can check the glow plugs while they are in the machine, but just checking for continuity will not tell you if they are heating properly. The ohm resistance must be within a certain range for the glow plugs to work as designed. On a LX 485 the service manual says .7 ohms */- .16. I know if they are not around .7 ohms the glow plugs will not work effectively.

I agree mike.......technically the threshold for the ISM glow plugs is 55 ohlms. My point is the glow plugs can be checked without removing them which is what exactle what ant says cannot be done.

 

[antfarmer2]

I agree mike.......technically the threshold for the ISM glow plugs is 55 ohlms. My point is the glow plugs can be checked without removing them which is what exactle what ant says cannot be done.

Did you read what you said lightbulb

 

[Mike10]

I agree mike.......technically the threshold for the ISM glow plugs is 55 ohlms. My point is the glow plugs can be checked without removing them which is what exactle what ant says cannot be done.

Cobra, I have not quite figured out why at the front of the service manual they give the 55 ohm stat but later in the manual when testing individual glow plugs it is .7 +/- per glow plug. Even adding all the glow plugs resistance together at the max spec does not equal 55 ohms. If you have some insight where the 55 ohms come from, I would appreciate it if you could educate me. Thanks

 

[jerry]

Cobra, I have not quite figured out why at the front of the service manual they give the 55 ohm stat but later in the manual when testing individual glow plugs it is .7 +/- per glow plug. Even adding all the glow plugs resistance together at the max spec does not equal 55 ohms. If you have some insight where the 55 ohms come from, I would appreciate it if you could educate me. Thanks

Go with what Mike says. I would guess your machine has glow plugs similar to my LX665, that is they are the 15 second ones not the earlier ones you used a longer glow on. Last winter mine became hard to start, checked the plugs with a ohm meter while they were in but disconnected. 3 were the same and the 4th was somewhat different. Took them out and the one did not glow. It made a huge difference in starting to replace that one.
However you say yours will only start on full throttle and if it sits for a bit it is hard starting. I would think that is more a fuel or engine condition problem. Even when it it 0 degrees out if I run mine and leave it sit for a couple hours it will start with little or no glow. I never have to use more than high idle throttle when starting it. But it also has synthetic oil in it so it spins faster and the turbo gets oil right away.

 

[jerry]

Go with what Mike says. I would guess your machine has glow plugs similar to my LX665, that is they are the 15 second ones not the earlier ones you used a longer glow on. Last winter mine became hard to start, checked the plugs with a ohm meter while they were in but disconnected. 3 were the same and the 4th was somewhat different. Took them out and the one did not glow. It made a huge difference in starting to replace that one.
However you say yours will only start on full throttle and if it sits for a bit it is hard starting. I would think that is more a fuel or engine condition problem. Even when it it 0 degrees out if I run mine and leave it sit for a couple hours it will start with little or no glow. I never have to use more than high idle throttle when starting it. But it also has synthetic oil in it so it spins faster and the turbo gets oil right away.

You have checked for power at the glow plugs also? Some people have had trouble with the preheat relay.

 

[Joe dh]

You have checked for power at the glow plugs also? Some people have had trouble with the preheat relay.

Thanks for the input, i will pull the glow plugs and test test them. i will reply with the results once im done. its frustrating cause the machine sits in a heated garage all the time and still has problems starting. any ideas on how to check the preheat relay?

 

[Joe dh]

Thanks for the input, i will pull the glow plugs and test test them. i will reply with the results once im done. its frustrating cause the machine sits in a heated garage all the time and still has problems starting. any ideas on how to check the preheat relay?

If the glow plugs and the relay test out ok, what would be the next course of action???

 

[antfarmer2]

If the glow plugs and the relay test out ok, what would be the next course of action???

Did you check the bleed valve and shut off valve if you have one and any bad looking fuel lines could be sucking air or pluging pick up line.....did you pull the glow plugs and see if they glow all the way to the tip I had some that tested good in it but did not glow good enough to work

 

[antfarmer2]

Did you check the bleed valve and shut off valve if you have one and any bad looking fuel lines could be sucking air or pluging pick up line.....did you pull the glow plugs and see if they glow all the way to the tip I had some that tested good in it but did not glow good enough to work

Then a compression test may be in order

 

[Joe dh]

Then a compression test may be in order

thanks antfarmer2, i will check the glow plugs and as far as the lines go, they have all been replaced. the compression test is what im affraid of lol

 

[antfarmer2]

thanks antfarmer2, i will check the glow plugs and as far as the lines go, they have all been replaced. the compression test is what im affraid of lol

Take a good look at that bleeder valve cheap and easy

 

[antfarmer2]

thanks antfarmer2, i will check the glow plugs and as far as the lines go, they have all been replaced. the compression test is what im affraid of lol

New thought did this start after replacing the fuel lines?

 

[Joe dh]

New thought did this start after replacing the fuel lines?

No, the fuel line replacing was an attempt to solve the starting problem. Gonna go pull out the glow plugs now and will let you know. I will check the bleed line too. Ill keep you posted.

 

[frogfarmer]

New thought did this start after replacing the fuel lines?

The ISM engines have a mechanical governor with a start spring that opens the rack to the full fuel setting if the engine is not running. It sounds like you may have a few issues at work here but a single spring could lead to having the throttle on full to start. A weak injection pump also gives the same signs because they have a hard time making pressure at cranking speed but are able to make pressure at idle and above. I know the glow plug issue has been covered but these engines require a glow system to start its not an option so when it gets weak the engine will be hard to start even on a warm day or in a heated garage. I have a couple of the 4cyl ISM engines in the shop now and 1 had simular symptoms to yours and it was the glow plugs. One of the plugs was bad one wouldnt heat to the tip and the tie bar was loose. Fixed those issues and she barely made a revolution before she would light and run.

 

[antfarmer2]

The ISM engines have a mechanical governor with a start spring that opens the rack to the full fuel setting if the engine is not running. It sounds like you may have a few issues at work here but a single spring could lead to having the throttle on full to start. A weak injection pump also gives the same signs because they have a hard time making pressure at cranking speed but are able to make pressure at idle and above. I know the glow plug issue has been covered but these engines require a glow system to start its not an option so when it gets weak the engine will be hard to start even on a warm day or in a heated garage. I have a couple of the 4cyl ISM engines in the shop now and 1 had simular symptoms to yours and it was the glow plugs. One of the plugs was bad one wouldnt heat to the tip and the tie bar was loose. Fixed those issues and she barely made a revolution before she would light and run.

Any luck yet?