H Motor Smoke Screen At Cold Startup

[kulangot]

78 HJ45 Pickup with H motor, recently rebuilt down in Nicaragua.

Lays out a nice naval sized white smoke screen at cold start , not so bad at warm start. Motor runs decent once warm with a fair amount of black smoke under full throttle accelleration.

I see over 12.5 V's at the battery and a voltage drop of 9.5 or so at the glow plug bus bar when energizing the relay, so I am thinking bad relay.

Any ideas of what a good aftermarket relay is? Nothing electrical on this truck is Nippondenso anymore, all hand made wiring from Nica. Anyone have a HJ45 harness for sale

Also, if the glow plug button on the dash (non OEM) is pumped during startup, it seems to run a lot better.

I know little about diesels. Will a bad glow plug relay make this H motor smoke excessively even in the summer?

Thanks in advance

 

[roscoFJ73]

The white smoke at start up sounds like some air is getting in when its been off for a while.

The excessive black smoke is probably the injectors

You could also test the glow plugs. I have a simple button for glowing the plugs and it works fine.
A glow plug relay would not affect the motor once its running and warmed up.
However if it is not working properly it will affect the start up .

 

[kim]

"Lays out a nice naval sized white smoke screen at cold start , not so bad at warm start. Motor runs decent once warm with a fair amount of black smoke under full throttle accelleration."

I had a similar situation with my HJ60, 2H, with the white smoke on cold start. Injector cleaning fixed it for me.

 

[Tapage]

"Lays out a nice naval sized white smoke screen at cold start , not so bad at warm start. Motor runs decent once warm with a fair amount of black smoke under full throttle accelleration."

I had a similar situation with my HJ60, 2H, with the white smoke on cold start. Injector cleaning fixed it for me.

Ditto ..

If your 2H runs nice when it warm up .. and you have clean air filter, new oil and oil filter .. diesel filter, your inyector aren't spray ( atomize ) right the diesel ..

Interesting my 1HD-T do it more than my 2H

 

[honk]

try advancing the pump tming a couple of degrees. Retarded timing will ofen bring white smoke.

 

[Greg_B]

1) Check the glowplugs with a meter for continuity. If bad, replace.
2) Check the busbar for voltage with a meter, and see what the system is getting hit with when you push the button.
3) Ensure valve set is current.
4) Check compression.
5) Ensure fresh air and fuel filters.
6) Try a double dose of a good cleaner like Lubro Moly Diesel Purge.

Good idea as mentioned to have the nozzles checked for spray pattern and crack open pressure.

Not likely the relay, but could be. I would check all the above 1st.

hth's

gb

 

[bigbrowndog]

Does the motor start ok with out blowing white smoke after it has been running for a while? As you say the motor has been rebuilt you should have good compression.I would try holding the glow plug button in for 10 to 20 seconds before cranking the motor and while cranking and note the difference.Have you checked the condition of the glowplugs, have the tips burnt off? The longer you crank the motor with out it fireing the more white smoke you will blow as unburnt fuel.If the H motor is running ok there should not be great clouds of black smoke either especially with a 2H. If it is blowing excessive black smoke I would check the injectors for poor nozzle spray pattern , overfueling and check pump timing and air filter.

 

[kulangot]

Pump timing has been set by a diesel mechanic, but an old friend of mine who is a Mercedes Diesel guru said that it needs to be flow timing to really get it right. I am going to try to get him to give me a hand doing that.

At this point, see a 3+ volt drop at the busbar for the glow plugs makes me think it needs a new relay.

The motor does start up well warm or cold and does not blow much smoke when it's hot.

I am starting to get a gut feeling that there is both a glow plug problem (relay and or plugs) and an injector problem.

Need to start throwing in some parts.

Air cleaner, fuel filter, gas tank and lines are all new.

thanks for all of the tips.

-

 

[kulangot]

Does the motor start ok with out blowing white smoke after it has been running for a while? As you say the motor has been rebuilt you should have good compression.I would try holding the glow plug button in for 10 to 20 seconds before cranking the motor and while cranking and note the difference.Have you checked the condition of the glowplugs, have the tips burnt off? The longer you crank the motor with out it fireing the more white smoke you will blow as unburnt fuel.If the H motor is running ok there should not be great clouds of black smoke either especially with a 2H. If it is blowing excessive black smoke I would check the injectors for poor nozzle spray pattern , overfueling and check pump timing and air filter.

Off the subject, but that's a cool looking dog you've got there. Boxer? Bullie?

 

[bigbrowndog]

Off the subject, but that's a cool looking dog you've got there. Boxer? Bullie?

He is a mastiff cross and a good mate.