12v 71 turbo tune up ??

[major hattitude]

I can only start engines if block heaters
I talked to DD mechanic and he recommended
To do a tune up he asked who marinized
The engines I told him I believe it was convo from
And also asked if I know what the injector
Hight and throttle delay setting spec was
If anyone can let me know where to find
These specs and any ideas on cold start
It would be greatly appreciated Tks John

[Boatsb]

The mechanic can run the serial number and get all the info he needs.

[dottieshusband]

The throttle delay is a distance measurement. On one of the racks there is a little piston and it adjustable by moving a clamp on the rack tube. I've got a gauge to measure it with, but IMHO it's doubtful it's your starting issue. I'd venture a guess that it is a fuel issue (if not a compression issue). I've had little air leaks in fuel lines and filters which allowed fuel to siphon back to the tank...so when I cranked it, it took forever to reprime to system through cranking. Once I figured out what was going on, a fixed the little air leaks, had full racors, and full engine fuel filter, the engine would jump to life. It's possible the rack isn't closing in the right position, but you can check it easily by removing a valve cover. Try advancing a throttle before cranking and see if that makes a difference. Check the stop solenoid rod and governor fuel advance lever.. Another thought is that the engine cranks faster with the engine oil heated, you should be able to hear that difference. That could point to a battery issue, or a compression issue..

[kelpy]

The rack is always at full fuel until the engine starts and the governor pulls it back to the throttle setting.

[dottieshusband]

The rack is always at full fuel until the engine starts and the governor pulls it back to the throttle setting.

It SHOULD BE! The rack has gimbal bearings on both ends a could get in a bind, it also has a return spring that could weaken with age, and a linkage rod from the throttle advance lever on the governor that could possible bind. That's why I suggest advancing the throttle, and hence the rack, if is stuck in something other than the full position, to see if that makes a difference when starting. If it only starts when the block heater is on, think about what is different when the block heater is on? The only thing I can think of is the viscosity of the oil is thinner, and the engine (mine anyway) would crank faster...and more fuel entering the cylinders, and higher compression if you've got leaky valves or rings. Depending on how confident you are with your mechanical ability, assume the rack is not fully open and mechanically advance it with the throttle lever and try that, or remove the valve cover and observe the start position of the rack. Pull some injectors and check compressions... I hate to say it, but the injector height setting varies by type, I've got N90's, but you may not...so you've got to read the manual (RTFM). But as Karl Dean said in Sling Blade, check the simple things first!

[Fanfare]

These engines are extremely complicated. The parts are often interconnected, and what you do to one can affect others. If you are not sure what to do I would advise finding a certified Detroit Diesel mechanic. He will know what to do. Be there. Watch what he does, have him explain, and maybe you can do it yourself next time. Otherwise you can waste a lot of money or even harm your engines. It doesn't sound like your present mechanic is up to this. I wouldn't take that chance.

[saltshaker]

Is this a new issue and does it need the heaters even when the water and air temps are warm? When it's cold out they are harder to start. If the batteries are marginal they'll be very hard to start. The block heaters make it easier to start period. Not sure what a tune up would do to improve cold start. Check your batteries and connections to make sure your getting enough juice to the engines.

[major hattitude]

Tks for all the great input we are going
To run the serial numbers and see what
We find

[oscarvan]

These engines are extremely complicated.

You've never worked on a 1993 Rolls Royce have you?

They're not complicated. They are different, and you have to do the homework. But after that it's all spanners and feelers. No Voodoo.

[MikeP]

You've never worked on a 1993 Rolls Royce have you?

They're not complicated. They are different, and you have to do the homework. But after that it's all spanners and feelers. No Voodoo.

Jeez, you mean the chicken legs I have hanging in the ERs, the Charles Kettering dolls perched on each engine, and my daily offerings at the small Green Leaker shrine in the forward cabin is unnecessary?

It may be so but my DDs run really well and I'm not taking any chances...