Missing Engine ?

[john510]

I have a 1995 Mack CH model tractor with an E7 300 Engine in it.

Lately When I went to start it when the engine is cooled off it will sound like it missing and blowing some smoke. Yes it sound like its missing, after it warms up for 10 -15 minutes it begins to run fine and no smoke but after running for 5-10 minutes an Orange light on my dash comes on saying “Electrical Malfunction” the truck does this after it cools down for about 1 hour. If I start it and shut it down and restart it quickly there is no miss or smoke?  What is your opinion on what could this be? I have a feeling it may be a injector but want to make sure?

[Mack Technician]

On 5/7/2020 at 10:40 AM, john510 said:

I have a 1995 Mack CH model tractor with an E7 300 Engine in it.

Lately When I went to start it when the engine is cooled off it will sound like it missing and blowing some smoke. Yes it sound like its missing, after it warms up for 10 -15 minutes it begins to run fine and no smoke but after running for 5-10 minutes an Orange light on my dash comes on saying “Electrical Malfunction” the truck does this after it cools down for about 1 hour. If I start it and shut it down and restart it quickly there is no miss or smoke?  What is your opinion on what could this be? I have a feeling it may be a injector but want to make sure?

The start up miss and smoke is normal. You probably have a V Mac II engine controller, not a mechanical pump. It uses engine oil psi to mechanically adjust timing. That’s why a shut off and restart gives the appearance of “cleaner start”, the oils already there. Check the injectors anyway, you might need some, it’s a common maintenance item

Get your blink code off the dash when it goes active.  

Edited May 12, 2020 by Mack Technician