Mild Thunder

Thanks staxx. The tach needle does move around a little like it's shakey. I checked the ohms on the tach sensor and it was about 275 ohms. The tem sensor was about 150 ohms. It will idle smooth for a minute, then get shakey. When revving it sometimes it's smooth, sometimes it's missing/stumbling a bit. The truck always started with the whole smokey powerful ecovonance mode in the morning. I noticed today when it started it didn't start like that. Kinda cranked a bit then fired but not with its usual "authority "

Fooled with a bunch of wires all day. Finally before giving up, I found the TDC sensor wire rubbing on the engine block, where it had rubbed thru the wire insulation. Got it moved, taped the wire up, and truck started. However, its running a little rough right now. Sometimes idle smooth and rev's smooth. Then will start idling rough, and while revving it will miss/hesitate a bit. Thinking about replacing the TDC sensor, and maybe the TEM sensor, as the wires going into the TEM sensor dont look so great either.

Actually I take that back. Only getting 3.5 volts to the fuel actuator terminal.

Ok not getting power to the 12v pin at the injection harness plug. Vmac fuse is good. ???

I do know that when I turn the key on, my volt meter is showing voltage. Also, yesterday i checked that solenoid with a test light and got power in/out with key on. I'll check it while cranking with a voltmeter today. Wish i had a pinout of the harness that goes to the injection pump. As far as fuel goes, the truck has 2 new fuel filters I put on, filled with fresh diesel. A new supply pump installed. I get fuel out of the supply pump while cranking. I get fuel out of the return line back to tank while cranking. I cracked open a couple injector lines, no fuel there. While cranking I get no smoke, or anything from exhaust. I am guessing the problem is between the supply pump, and injector lines. Which leaves me with the injection pump itself, or something that controls the injection pump? ECU, fuel shutoff, wiring, etc

Does anyone have a vmac II manual ?

Thanks, I will check that in the morning!

Thanks, I did that today. Looked good in there. Being a hobbyist, from cars, to boats, to all kinds of stuff, its always been pretty awesome to be able to go on the web and get information on how to. I gotta see if I can access a manual for this truck to start running some sort of diagnostics to be able to test things, before bringing it to the dealership. This truck has been nickel and diming me to death these past couple months, any profits i've made have went right back into the truck, and this problem may end up being the nail in the coffin if something doesnt go right for me soon. A new rig isnt in the cards, and sinking 5000 into this old truck isnt either.

Thanks for the help! No, there is no check engine light. Engine was running great prior to this. was trying to avoid bringing it to the local mack dealer. They have been known to take a while to get to the repair, and very costly. Plus another 400-500 tow to get it there isnt sounding good!

Darn. So the fuel shutoff is internal?

Would this be the fuel shutoff solenoid?

Installed new supply pump today, no luck there. I have a feeling it's something electrical that controls the fuel shutoff valve, however I don't know where that's located to even begin checking voltages for it. So far 400 bucks for a tow, 300 for a fuel pump, and 2 days lost work. Next is probably gonna be having to get it towed to the mack dealer.

Also, noticed the engine cranks over hard, like fast hard. Not like it doesnt have compression, but like I just installed 3 new mega batteries.

Pretty sure its a basic E7 With injection pump. Do the fuel shutoff solenoids go bad on these trucks?

Thanks for the help. I dont know if its an Etech, but the setup looks like this one in this picture?. http://www.dieselengineindustries.com/images/inventory/1_1.jpg