fjh

68 350-400 hp were Vmac the 300 could be either or in this vintage! If its mechanical there is a screw under the lever on the side of the pump the rear ward screw adjusts the idle!I belive 8 mil or 10 mill wrench to do the job. You can, If its turned on in the puter adjust the idle with switches as well if its Vmac!

First off Id check for Boost leaks High pyro indicates among other stuff lack of air!Pluged air filter poor turbo performance yada yada Before spending big bucks! Just my two cents

Well if Hes a bro and you want to help out then Its A call that you got to make! Its a truck, trucks break! Can he help keep the bandaids on! I'd feel better putting him in an older unit Sumthing I new wasn't going to break down leaving him with decisions to make with your money is all! Just somthing to think on!

Man you done everything your doing the last resort thing now!Let Us know how it goes!!!!!! Your in the era for casting sand in the block I beleive, was there ever any compressor over heat problems? Also low liners! has it been blowing coolant out?Or over preasuring the rad?We had one truck 2000 era blowing water filters off!Bubble tests don't work well as you can't check under load Been my observation the gas test kits are junk on a diesel engine they show nil! Just guessing but If this cooler don't do the trick Liners would be my bet! I think your real close for time on the cooler change out! Just some thoughts

I Can tell you tell ya that the truck was dressed out at our shop on Vancouver Island and made its way to the other side of the Nation! http://nanaimomack.com/ Check out westcoast edition! As for buying another truck Naw two headaches.Ya can't count on somone else to do the job properly!Your just buying him a job!

This here is too vague. Is this a VMac engine?What is fairly common on a vmac pump is the rack actuator fails!In this case the pump has to come off to be repaired! HK brings up a good point is the dash lighting up when the key is turned on?The acc relay will cause the heater and dash not to work! And will not let theengine light up!

I agree its time to count!

Ryan I bin following this post and the input has been all valid here!I would how ever check the top gear sets on both diffs for peices if you havent already,pull the side covers and look at em.your ratio mis match is highly likly at this point wouldn't take very much with this style of interaxle drive to cause a problem like this! I beleive this was mentioned But again, If one of the diffs has a Mack limited slip in it, this will bang and pop. Bud or spoke Wheels? spoke Are they Tight? Simple but valid questions Cracked bud wheels make one heck of a noise!

Barry posted this above there but its good reading! Why we are going the way of the doe doe bird as far as I can see! Reading thru that I see they will do away with the owner ops Won't be able to afford trucks as repair costs are off the end of the scale they are catering to fleets The guy states that newer trucks are more durable and more dependable in one of his last statments he odviously lives on mars or sumthing! http://www.truckinginfo.com/maintenance/news-detail.asp?news_id=69639&news_category_id=76

First thing that comes to mind is the fuel pump Plug pins!I would have them replaced before doing anything else major!

SweeeeeeeeeeeT Got to love that!

Gambi said he could use that screw theres a bit of money on the sly here for ya Chuck! Pop that baby in the mail to him!

Welcome to the site ! Would you please post your problem before you go bald! We maybe able to help with out a diagram

On a truck these are mounted at the rear upper of the fuel pump governer housing!As stated there will be a braided or steel 1/4 inch line coming from the inlet manifold!

Not sure

Ya I worked to day Bro, I come to check on ya most every day thou!Got to keep you and Jerry on the straight and narrow!

Glenn they should work however how well I'm not sure. the tips and cracking preasures maybe diffrent. Cant hurt to try I would think! 270- 300 M? Would be a stump puller engine I would think! Maxidyne !?

First do you have all the fuel lines for the ambac? You would have to swap ALL the rigging over from the ambac engine Pump drive ect and you need to make plugs to go into the holes where the rob pump was!I beleive the gears on the front are the same.there is and oil feed hole that May be pluged off on the robby engine that feeds the ambac pump drive!It Is a fair amount of work!I beleive the turbo drain is diffrent not sure on that I beleive the turbo on the robby will be schwitser and the ambac it will be a Garret! you'd have to check this stuff!Then the trotle linkage and the stop stuff you'll have to fiddle with! Lots of messing about for little gain.Try tweaking the timing 2 or three deg advance and see if it gains you your .3 or 4. I to like the ambac stuff better but they sort of droped it in the 90's cause robby was cheaper I beleive.The ambac pumps seem to run the engines cleaner for some reason specialy V8s.

Swap the 400 parts on to the donor engine! How did the 400 fail? You can safley take 460-500 from the block Wouldn't wan't to thou!

The rob bosch injectors look diffrent as well the alinment Kog is a ball bearing as apose to a roller bearing looking thing!Timing Its all over the place depending on year19 -24 degres if I rememeber correctly!What is the year of the engine? I might be able to find out for ya!

No screws in the engine! all have bolt heads! I have seen that screw used on the clutch cable lock tab! also on the clamps that hold the p/s hoses around the bottom of the engine but nothing to my recall inside the engine like that!

The way I read this is your ambac injectors are still in the heads Correct? Most times the injection pumps are calibrated with the injectors ,so the cracking preasures May be diffrent between the injectors!Having said that I guess you could advance the timing a bit your problem being the ab light or lack there of! you could try and wing it and set the timing by first putting the engine on the desired timing number on the fly wheel then center the timing tab in the pump where the ab plug goes in the hole by eye But your kind of guessing could be off 1 or 2 degrees!

Ya it can wait For a bit! Seen em get real bad thats probly your noise! At one point in time it was a saftey issue to replace fuel lines If I were doing it To my Truck now I would re use the lines!Providing they are the updated lines. If I am doing a repair to Your truck I will replace the fuel lines as it is a liability issue for Me!You can do this repair your self!For the cost of the gaskets and the stud kit ,It will take you the best part of a day to do if your doing it your self and never done it before!It will take me or anyone thats done a few 3 to 5 hours to do,If it has any broken studs abit to alot longer. Warrenty pays 4.7 or there abouts to do it!With out complication. So A case of beer and a nice sunny relaxing sunday do it your self save 500 or more bux labour or sit at home with your feet up drink that case of beer and don't lift your butt out of the chair and let somone else do it for ya and get six months to one year warrenty your two choices! Injection lines will likly get replaced if done at a dealer.Duno what the gaskets cost!NOT MY DEPARTMENT,You need six manifold gaskets update stud spacer kit, two hot side egr pipe orings one turbo drain gasket one turbo gasket, turbo studs and nuts and lots of patience.It gets easier after about the third time around! Your call Chuck!

When you put it back on Because you put it on the Timing marks before you started (Correct) You now only got to remove the plug pear into the hole once the pump is back on be sure the flat blade is dead center in the window and bolt the gear up put the cover on see how it runs!The Ab light thing is a bonus if you can get one if not and the engine dosent run to satisfaction take it to the dealer pay the .5 to and hour and have them time it!You still saved the re and re!

No engine is perfect! Get a sample to ease your mind! If your operating in humid condions this wouldn't help things!