Glow Plug Issue

[hollywd75]

Kind of sounds like you have gelled fuel.

It did this same behavior when it was above freezing, it's not just cold related. Even at 50 degrees outside it won't start unless I use ether. It does have treated fuel in it though, just in case.

The old glow plugs were definitely no good so I thought that was it, and/or something with the after market ignition switch, but it's not since those have been replaced and work fine now. It runs fine once it's starts, and starts easily once it's been running and all warmed up.

The battery tested 12.4V, but I'm starting to wonder if maybe there is something going on there, not enough juice. It has new cables and connections are clean. It's a 700CCA ACDelco. I need to test it under load - I wasn't able to before as I need a second pair of hands. I read somewhere it should test around 9.6 under load, a bit less if it is cold out.

 

[toot77]

My current thoughts in no particular order;

- for the engine to start, your diesel engine requires 1) +12vdc has to be provided to the fuel injection solenoid on the injection pump. 2) +12vdc to the starter motor & starter solenoid. 3) +12vdc supplied to the glow plugs. 4) Fuel injectors and injection pump.

- You indicate that you have replaced parts. Are you using New Holland OE or OE supplier parts? Some of the cheap import aftermarket parts can be questionable. If your battery voltage is good (12.8 or higher) and the engine cranks when turning the key to 'start', I would then check for +12vdc at the injection pump fuel solenoid when the ignition key is turned to 'on'. You should also be able to feel the solenoid click when turning the key to 'on' by holding your hand on the solenoid. Ultimate solenoid test is to remove (unscrew) the solenoid so you visibly see the plunger move. Next would be to verify glow plugs by checking for +12vdc when turning the key to 'heat' (as long as you hold the key in 'heat', you should have the +12vdc. The ignition swithch is probably good if the glow plug light turns on for 4-5 seconds when in the 'heat' position. Glow plug voltage will not go to zero when the light goes out, it stays at +12vdc as long as you hold the key in 'heat' on a TC30. If voltage is good, remove and check each glow plug resistance. I think it is supposed to be something like 0.8 ohms. Check that it has the correct glow plugs. After all that, I think you would down to a fuel injection issue or an engine compression issue.

- If your service manual is a New Holland manual, it will have detailed schematics of each system (i.e starting, glow plugs, etc.) that show detail of each component along with diagnostic instructions for each component that provide additional information beyond the overall wire harness diagram. That makes troubleshooting with a test light or meter easier. I do not know how detailed aftermarket manuals may be.

ps in regards to my note about oe versus aftermarket parts, the oe glow plug lamp timer is made by NGK and NGK replacements are found online for $20-$30 which seem to work fine. The same for glow plugs, NGK and Beru are both oe suppliers and as long as you cross to the correct supplier number, you should be good. I avoid no name cheap parts when possible.

 

[mjonesnh]

It did this same behavior when it was above freezing, it's not just cold related. Even at 50 degrees outside it won't start unless I use ether. It does have treated fuel in it though, just in case.

The old glow plugs were definitely no good so I thought that was it, and/or something with the after market ignition switch, but it's not since those have been replaced and work fine now. It runs fine once it's starts, and starts easily once it's been running and all warmed up.

The battery tested 12.4V, but I'm starting to wonder if maybe there is something going on there, not enough juice. It has new cables and connections are clean. It's a 700CCA ACDelco. I need to test it under load - I wasn't able to before as I need a second pair of hands. I read somewhere it should test around 9.6 under load, a bit less if it is cold out.

If you have a jump pack, hook to battery and see if extra juice will get you going. My tractor battery checks good but used jump pack to give it extra juice. Definitely made 0º F starting much easier.

 

[hollywd75]

My current thoughts in no particular order;

- for the engine to start, your diesel engine requires 1) +12vdc has to be provided to the fuel injection solenoid on the injection pump. 2) +12vdc to the starter motor & starter solenoid. 3) +12vdc supplied to the glow plugs. 4) Fuel injectors and injection pump.

- You indicate that you have replaced parts. Are you using New Holland OE or OE supplier parts? Some of the cheap import aftermarket parts can be questionable. If your battery voltage is good (12.8 or higher) and the engine cranks when turning the key to 'start', I would then check for +12vdc at the injection pump fuel solenoid when the ignition key is turned to 'on'. You should also be able to feel the solenoid click when turning the key to 'on' by holding your hand on the solenoid. Ultimate solenoid test is to remove (unscrew) the solenoid so you visibly see the plunger move. Next would be to verify glow plugs by checking for +12vdc when turning the key to 'heat' (as long as you hold the key in 'heat', you should have the +12vdc. The ignition swithch is probably good if the glow plug light turns on for 4-5 seconds when in the 'heat' position. Glow plug voltage will not go to zero when the light goes out, it stays at +12vdc as long as you hold the key in 'heat' on a TC30. If voltage is good, remove and check each glow plug resistance. I think it is supposed to be something like 0.8 ohms. Check that it has the correct glow plugs. After all that, I think you would down to a fuel injection issue or an engine compression issue.

- If your service manual is a New Holland manual, it will have detailed schematics of each system (i.e starting, glow plugs, etc.) that show detail of each component along with diagnostic instructions for each component that provide additional information beyond the overall wire harness diagram. That makes troubleshooting with a test light or meter easier. I do not know how detailed aftermarket manuals may be.

ps in regards to my note about oe versus aftermarket parts, the oe glow plug lamp timer is made by NGK and NGK replacements are found online for $20-$30 which seem to work fine. The same for glow plugs, NGK and Beru are both oe suppliers and as long as you cross to the correct supplier number, you should be good. I avoid no name cheap parts when possible.

Thank you for these detailed steps, I will check these next if the battery tests good under load. I believe the lamp timer and glow plugs are NGK. My service manual is the NH one, I bought the pdf version. The ignition switch is aftermarket, I didn't have the funds for the overpriced NH one.

 

[hollywd75]

If you have a jump pack, hook to battery and see if extra juice will get you going. My tractor battery checks good but used jump pack to give it extra juice. Definitely made 0º F starting much easier.

I don't, but I may be able to borrow one - good idea!

 

[grsthegreat]

Thank you for these detailed steps, I will check these next if the battery tests good under load. I believe the lamp timer and glow plugs are NGK. My service manual is the NH one, I bought the pdf version. The ignition switch is aftermarket, I didn't have the funds for the overpriced NH one.

Does the aftermarket one have a glow plug circuit like original one? All switches aren’t created equal

 

[nyone]

Even at 50 degrees outside it won't start unless I use ether. It does have treated fuel in it though, just in case

I would suspect your not getting fuel. Have you cranked it and cracked the injector lines? You should get some high pressure fuel out of it.

 

[toot77]

I believe the lamp timer and glow plugs are NGK. My service manual is the NH one, I bought the pdf version. The ignition switch is aftermarket, I didn't have the funds for the overpriced NH one.

The aftermarket switch might concern me a little. The reason being that because there is no glow plug relay, full glow plug current does pass through the switch contacts. I know the HN price is ridiculous, but some of that low cost no name import stuff is 'get what you pay for'. Might check voltage at the glow plugs with all glow plugs installed and connected to see if the switch is causing voltage drop. Should that be a problem, you could reduce current through the switch by adding an automotive relay into the circuit, BUT only start making mods like that after you figure out the issue.

Checking the pinout configuration of the aftermarket switch is a good idea also, as mentioned above.

The NH pdf manual should be fine. It will have the more detailed circuit info, such as the switch pinout, etc..