Working on Stuck Injectors

[NutherNewbie]

Hi all,

I'm working on an 8V71 that last ran about 10 years ago (ran pretty good according to the PO).

I took one rocker cover off and found a gummy injector that could be pried with a screwdriver and 3 more that were solidly stuck.  Then I took the fuel tubes off and sprayed lotsa Liquid Wrench into the ports.  The gummy injector freed up really well but the others didn't.  This engine does have the spring-loaded rack levers, BTW.

I can't pry hard enough with a screwdriver to move the 3 stuck racks, so I'm wondering about lightly hammering on the followers.  Not clear from the manual if that would damage the injectors, so I thought it best to ask the pros.

Is it okay to rap on the followers?  Is that a step in the right direction?  Steel drift okay or better to use brass or a piece of wood?  Light taps with a light hammer best or would heavier be okay?

Thanks.

PS. Don't want to remove or replace the injectors because I'm not capable of doing all the adjustments that would be needed afterward (and don't have time to learn right now)

[chessie4905]

Hook up an electric fuel pump to circulate injector cleaner through the head fuel lines and return line that goes back to tank. Do it for about an hour or two and then let everything sit overnight to soak and loosen. Check the rack movement in the morning. Unless there is moisture and rust inside the injectors, they should loosen up. Lucas makes an injector cleaner and lubricant that should work. There are many other brands that should work also. Btw, when you get that engine started, don't run the hell out of it; just keep it at idle or a little above for about a half hour.

[c-coop]

spray carb cleaner into the fittings let it soak   usually works

[NutherNewbie]

Chessie 4905 - thanks for the helpful info.

Took a couple weeks but Chevron (with Techron gasoline freed up the stuck injectors.  Kinda scary thinking that if I'd started it first, it would've run away since all 8 injectors were stuck in max fuel position.  I've become a believer - check the injectors before trying to start any Detroit 2-stroke that has sat for a while!

Worked on some other things and finally started the engine a few days ago. First time in about a decade and it ran well - no cloud of blue/black/white smoke and oil pressure was good.  Ran it at high idle for a while and never revved it very high (that'll come later...

What are peoples thoughts and experiences with stuck DD 2-stroke injectors?  What things might contribute to the problem?  How long does it seem to take?  Anybody ever had an engine run away on them?

[Utahclaimjumper]

  Ive had several do it but none blew up,,always had a piece of plywood to slap on the blower,, wont run without air period.>>>Dan

[chessie4905]

Drive it easy when you get out on the road for 50 or so miles. Stop frequently and check for leaks and any other issues. An oil change would be a good idea before going out on the road. Before you started it, I would have cracked the oil drain plug a couple of turns and wait a couple of minutes to see if any coolant drips out. You can still check after it sits overnight, although most would be mixed with oil. An oil sample analysis could be done if you have a source to send it to.