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stevenjohnston2
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Hey guys I just completed a valve set on a 94 mach with an E7-427 engine. I set the intake to 0.016", the exhaust to 0.024" and the jake slave piston to 0.080", these are the specs on the valve cover and the jake spec I found online. After setting that I noticed that the injector tubes and injector lines on the side of the head looked like they were weeping a bit so I gave them a bit of a tightening. The truck ran when it came into the shop but idled a bit rough so that's why we did the valve set. Now the truck won't start it just blows white smoke from the stacks. Any ideas would be appreciated. Thanks

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Hey guys I just completed a valve set on a 94 mach with an E7-427 engine. I set the intake to 0.016", the exhaust to 0.024" and the jake slave piston to 0.080", these are the specs on the valve cover and the jake spec I found online. After setting that I noticed that the injector tubes and injector lines on the side of the head looked like they were weeping a bit so I gave them a bit of a tightening. The truck ran when it came into the shop but idled a bit rough so that's why we did the valve set. Now the truck won't start it just blows white smoke from the stacks. Any ideas would be appreciated. Thanks

How sure are you of your valve adjustment? What I mean is did you adjust the valves in firing order 1-5-3-6-2-4, do you know for sure which is the intake valve and which is the exhaust? I don't mean to imply anything with these questions, but it seems like something must have happened while you were adjusting the valves.

"Mebbe I'm too ugly and stupid to give up!"

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How sure are you of your valve adjustment? What I mean is did you adjust the valves in firing order 1-5-3-6-2-4, do you know for sure which is the intake valve and which is the exhaust? I don't mean to imply anything with these questions, but it seems like something must have happened while you were adjusting the valves.

I'm fairly confident but that said I still may have messed up. I set in that firing order and assumed the exhaust valve is the closest to the front of the engine, this is the valve with the Jake slave cylinder on it. Also I adjusted the valves on the push rod side of the rocker arm not the bridge side. Like I said I think I did it right but this the first time doing a valve set on a Mack so let me know what you think.

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I'm fairly confident but that said I still may have messed up. I set in that firing order and assumed the exhaust valve is the closest to the front of the engine, this is the valve with the Jake slave cylinder on it. Also I adjusted the valves on the push rod side of the rocker arm not the bridge side. Like I said I think I did it right but this the first time doing a valve set on a Mack so let me know what you think.

You got smoke that means ya got fuel!The valve set sounds suspect!With the lids off check for overlap (valves rocking) on # no six then set the valves on one and go thru the firng order ,what your doing is confirming compression on one with this only use the pointer on the flywheel for V/S

mated cylinders below If one is on compression six will be overlaping If 5 is on compression 2 will be over laping!

1 5 3

6 2 4

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I'm fairly confident but that said I still may have messed up. I set in that firing order and assumed the exhaust valve is the closest to the front of the engine, this is the valve with the Jake slave cylinder on it. Also I adjusted the valves on the push rod side of the rocker arm not the bridge side. Like I said I think I did it right but this the first time doing a valve set on a Mack so let me know what you think.

Sounds right. You used the marks on the flywheel? Did you do any other work on the truck at the same time? You might check to make sure you didn't kick or step on any of the electrical connections on the fuel pump.

"Mebbe I'm too ugly and stupid to give up!"

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I checked the electrical conections, that was an early thought for me. I looked for flywheel marks but couldn't find any. Are they on the face of the flywheel or on the side? The only other work as tightening up some fuel lines. Is there any way you can over tighten the pencil injectors into the head and damage them?

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I checked the electrical conections, that was an early thought for me. I looked for flywheel marks but couldn't find any. Are they on the face of the flywheel or on the side? The only other work as tightening up some fuel lines. Is there any way you can over tighten the pencil injectors into the head and damage them?

There is a plate on the bottom of the flywheel housing held on with six small bolts. Remove the plate and you should be able to see the outside edge of the flywheel. There are several marks on the flywheel that denote degrees of rotation (used for timing the fuel pump), continue turning the engine, clockwise as viewed from the front of the engine, from the "TC" mark and you should come up on a mark that says "1 & 6 VS" or just "1 & 6". This is the valve set mark for cylinders one and six. You will need to determine which set of valves (cylinder 1 or cylinder 6) to adjust. The set to be adjusted will have the pushrods lower in the block, so less of the pushrod is visible sticking up out of the head. Adjust the valves on that cylinder and then "bar" the engine, in normal rotation to the next valve set mark (which is 120 degrees from the last one) which will read "2 & 5". If, on the last cylinder you adjusted cylinder one, then this time you will adjust cylinder 5. You can recheck the pushrods as described previously just to make sure of your positioning. Continue on with your adjustments in this fashion until all six cylinder are adjusted. It will take two full revolutions of the engine to adjust all six cylinders. You may need to clean the edge of the flywheel off in order to see the marks as they are stamped or punched prettly lightly into the flywheel.

"Mebbe I'm too ugly and stupid to give up!"

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I checked the electrical conections, that was an early thought for me. I looked for flywheel marks but couldn't find any. Are they on the face of the flywheel or on the side? The only other work as tightening up some fuel lines. Is there any way you can over tighten the pencil injectors into the head and damage them?

Nope ! you can't hurt the injectors unless you get really aggressive. Go thru the valve set again somthing is messed up !Follow one or both of the afore mentioned instructions to get your self back on track!If your stuck for Valve set marks on the fly wheel , the set can be done on overlap on the rest of the cyl's as I discribed earlier, in firing order .

1 5 3

6 2 4

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Nope ! you can't hurt the injectors unless you get really aggressive. Go thru the valve set again somthing is messed up !Follow one or both of the afore mentioned instructions to get your self back on track!If your stuck for Valve set marks on the fly wheel , the set can be done on overlap on the rest of the cyl's as I discribed earlier, in firing order .

1 5 3

6 2 4

Sorry fjh, I somehow missed your earlier post.

"Mebbe I'm too ugly and stupid to give up!"

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Thanks for the good advice guys, I went back over the valve set and the exhaust valves were tight when it was lined up with the timing mark on the fly wheel. I completed a full valve set and the truck started with no problems and runs great. Thanks again for all of the help.

Glad to help.

"Mebbe I'm too ugly and stupid to give up!"

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