Meghan
New Member
Hey there.
Having some trouble getting a Detroit 6-71T in-line to run at idle without manual control of the injector rack.
I am aware that this particular thread is for trucks, but I am resurrecting a pair of Johnson & Towers Detroit Diesel 6-71T engines in a sportfish boat. The boat sunk back in 2017, was salvaged, engines were drained and restarted, and then it was left semi-winterized until I took it over this year.
The port side engine was stuck when I first started working on her. Wouldn’t budge. I removed the valve cover, pulled the injectors and poured a mixture of diesel and Marvel Mystery oil into the injector holes until the engine was filled. After soaking, I was able to free things up and turn her over.
Before first start, I cleaned and tested each injector to ensure proper functionality before reseating them. I disconnected the fuel rod and put a pair of vice grips on the injector bar. I was able to fire up the engine and control throttle manually. Since that worked out and the engine wasn’t knocking or sucking air, I tried to reconnect the fuel rod linkage to see if I could get things idling without manual control.
I made sure the throttle was in idle position and hit the starter. The injectors sat in the full fuel position and the engine instantly tried to rev up out of control. I had left the vice grips on and was able to kill the fuel before things got out of hand.
Upon further inspection of the governor and throttle, it appears that the throttle lever barely moves the fuel rod. With all linkage connected, the stop lever will move the injector rack significantly more than the throttle.
I’ve tried running the rack and the adjusting the gap in the governor but didn’t make any difference. All parts seem to be intact.
Engine: JT Detroit Diesel 6-71T
Governor: 5183314 Single weight variable speed
Injectors: Reliabuilt M15 (all move freely)
I’d be extremely grateful for some help! Any ideas on what to try next?
Having some trouble getting a Detroit 6-71T in-line to run at idle without manual control of the injector rack.
I am aware that this particular thread is for trucks, but I am resurrecting a pair of Johnson & Towers Detroit Diesel 6-71T engines in a sportfish boat. The boat sunk back in 2017, was salvaged, engines were drained and restarted, and then it was left semi-winterized until I took it over this year.
The port side engine was stuck when I first started working on her. Wouldn’t budge. I removed the valve cover, pulled the injectors and poured a mixture of diesel and Marvel Mystery oil into the injector holes until the engine was filled. After soaking, I was able to free things up and turn her over.
Before first start, I cleaned and tested each injector to ensure proper functionality before reseating them. I disconnected the fuel rod and put a pair of vice grips on the injector bar. I was able to fire up the engine and control throttle manually. Since that worked out and the engine wasn’t knocking or sucking air, I tried to reconnect the fuel rod linkage to see if I could get things idling without manual control.
I made sure the throttle was in idle position and hit the starter. The injectors sat in the full fuel position and the engine instantly tried to rev up out of control. I had left the vice grips on and was able to kill the fuel before things got out of hand.
Upon further inspection of the governor and throttle, it appears that the throttle lever barely moves the fuel rod. With all linkage connected, the stop lever will move the injector rack significantly more than the throttle.
I’ve tried running the rack and the adjusting the gap in the governor but didn’t make any difference. All parts seem to be intact.
Engine: JT Detroit Diesel 6-71T
Governor: 5183314 Single weight variable speed
Injectors: Reliabuilt M15 (all move freely)
I’d be extremely grateful for some help! Any ideas on what to try next?
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