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

Hey guys. Had the truck out today. Was a little low on fuel in the tank. Headed to the fuel station to get fuel and a coffee. I got about a mile from there, and the truck kinda started to sputter a little. Made it to the station, set the parking brake, and it was idling fine. So I shut the truck down, grabbed a coffee and fueled up. Got back in the truck, wouldnt start. Thought maybe it was air in the lines. Pulled the fuel filters, they were full. Pumped the hand pump a bunch and still nothing. Called a service truck out. He came out with fresh fuel filters, filled them with fresh fuel, nothing. He cracked open a couple injector lines thinking they were air locked, no help there. Actually no fuel coming out there either though. Gave it a couple sprays of ether and it would run on the ether for a second then stall back out. He blew the line from the tank and that was clear. He loosened the return line to the tank, and fuel was coming out while cranking. Ended up having to get a wrecker to tow it back to my yard. Any tips on what to check for next? Fuel Solenoid? Injection pump problem? Any insight would be great.

My 98 CH613 lost all the gauge lights. All the gauges work, but just no backlighting. Any ideas on what to check first? thanks!

Noticed a air leak coming from radiator area, followed immediatly by high coolant temps. Noticed the air line going into the fan clutch, was dangling there, with the fitting that goes into the clutch still attached to the air line??? The fitting appears to have a groove in it where there should be a o-ring. Is this something thats repairable or would i need a whole new clutch?? Nothing appears to have broken, the fitting looks intact, but whatever holds it into the clutch seems to be missing? Its a 1998 CH 613 with a E7. THanks guys!

Went to mack dealer tonight, to get the kingpin bearing, and parts guy says I have a bushing, not bearing, as its a meritor/rockwell axle. So could the bushing be worn?

Is this something I should just let the Mack dealer do?? Have them adjust valves and rebuild jake? About how many hours labor would it cost? Im only a few miles from the dealer but dealer prices scare me sometimes, but so does the idea of screwig up my motor trying to save a few bucks! lol

I have a 1998 CH613. I bought the truck a few years back. Bought it with 570k miles, and now it has about 690k. Runs very well. Power is good. Pulls 32lbs of boost. Engine is labeled 355-380HP, but previous owner says he had it turned into a 427HP?? Is that possible? I drove a stock 2000 year 355-380, and it felt like a slug compared to mine. That truck empty felt like mine loaded. Anyhow, I noticed my jake doesnt seem to be strong at all. it engages ok, but slowing/stopping power is minimal, unlike the other truck. I have not had the engine touched since i bought it. Someone told me i should have the valves adjusted. Is this the cause of a weak jake?? Thanks!

Hello, Im new here. I have a 1998 CH, and my drivers side steer tire is wearing badly on the inside. Outside is fine, along with passenger side tire showing no abnormal wear. A buddy told me its probably just a "kingpin" bearing, and its a easy fix. Something about dropping the lower nut, and just putting a new bearing in and retorquing? Can it be that easy of a fix?? Steering does seem to pull a little to the right. Truck is used off road quite a bit and potholes are ridculous around here. Thanks!!!