8V92 Detroit Kysor shut down issues

[JTFormula]

I figured I would post this here instead of my General thread. I replaced the Kysor shut off and now its not even firing up. The moment I crank the engine over, the piston extends and shuts the lever down. My old one had let the truck run for about a minute or so then it would shut down. Or if I raised the idle, it would shut down.

I installed the new, connected the power lead to the one side. tried it and it shut down. I grounded the other side, and the piston is still extended. I switched the leads to see if that makes a difference, no change. I am baffled! Here are pictures of the set up:

Any ideas you guys have, I would greatly apprecate it.

[farmer52]

That looks like it is the fuel shutoff, not an air supply shutoff. My suggestion would be to install a cable to manually shutoff the fuel. Put a return spring to hold it in the run position. Give my friend a call. Maybe you can find a service manual.

[theakerstwo]

With your old one I would say that it was not seeing a oil pressure signal. the moduel that controls the shut down and reset gives it self maybe 10 seconds or more to see oil pressure then it shuts down and is reset by the start mode. So what ever it was not seeing a oil pressure signal. The new one I don't know why. But you will have to get a manual to check it with. There is different ones. One system you have to hold a switch down or in till the oil pressure builds then it is in reset and the other resets from the starter switch.Google for the manual and I think you will find one.

[farmer52]

JT - been doing some searching on the interweb. The cylinder/solenoid is definitely connected to the fuel shutoff lever. Are you sure the line is to be connected to the air/boost and not an oil pressure line? Glenn may be onto something. If the cylinder does not see oil pressure, there is no current flow and the solenoid will not energize or move the lever. Back the the interweb......

[MidniteMechanic]

Cylinder is connected to trucks air tank. Just can't find my old Kysor wiring diagrams.

[farmer52]

Is the hot wire connected to a solenoid or relay somewhere? Have you checked all the fuses?

Did you try charging the air line with compressed air to see if the solenoid actuates?

Grasping for a solution.

[JTFormula]

Air line is connected to air pump behind the engine. It will do this with no power wire connected. It seems as soon as it starts to charge the air, it actuates the lever closed.

Ill double check this in the morning.

[theakerstwo]

Google has those manuals I found one and I am sure you can to.Just download it and use a test light. You will find the module some were in the dash and the sensor inputs go to it and a power wire to it as well as a starter mode wire.I have not looked a a manual in years but am sure the sensors only ground the imput circuits and the start mode wire to the module will get power to it only when you are changing it and you will need a ign power to it. They are simple.

[BC Mack]

With your old one I would say that it was not seeing a oil pressure signal. the moduel that controls the shut down and reset gives it self maybe 10 seconds or more to see oil pressure then it shuts down and is reset by the start mode. So what ever it was not seeing a oil pressure signal. The new one I don't know why. But you will have to get a manual to check it with. There is different ones. One system you have to hold a switch down or in till the oil pressure builds then it is in reset and the other resets from the starter switch.Google for the manual and I think you will find one.

JT

what he said....

for now just remove the air line and cap it, or remove the valve with line on... figure a way to manually move the lever to 'off' while you go about testing. If engine starts ok but the piston moves out as if to move the shutoff lever on the govenor housing then you have got a fail condition or an electrical short. I would not run for long without an oil pressure gauge to read, fuel pressure can be read by tapping into the spare 1/4pipe fitting on the secondary filter.

you WILL need a manual for your truck to see what the trigger is... it could be oil pressure, fuel pressure or alternator signal... there is usually an 'engine shutdown control relay' or 'engine cutout relay' and it will also be tied in with the 'starter control relay', the alarmsat (overtemp shutdown and alarm) and the low coolant sensor.

these things are a real pita but are there to save your engine, so don't get too pissed off with it.

the ones I have worked on are in GM buses with 71 and 92's but get complicated with front and rear start controls, gear stick microswitches and manual overides... I can't imagine your truck is that difficult, you just need to know what is triggering the shutdown.

it is merely a process but the manual and wiring diagram for YOUR truck will be a great help.

BC Mack

[JTFormula]

I have a wiring diagram already. It was in the truck when I got it. When I bypass the valve to fire it up, it shows good oil pressure, and good alternator charge on then dash gauges. I did check with a test light with the key on and no current was showing through the power wire.