fjh

Great thanks for the info

Now with the puff limiter d/c is that why we blow a bit of smoke?

Yup Black smoke on excel

Hi all,

Just wondering if someone can help me with what I am looking at on my R688RST.

What are the two components circled?? Should they be hooked up anywhere?

Teh first pic is the engine brake trigger

The second two are the puff limit or smoke control device!Both cases won't hurt anything!

What exactly does this air line do? It isn't hooked up on my truck and is the blue line in the following pic.

I just want to make sure having these things not hooked up won't hurt my engine!!

He said not to quote him...

He quoted spec.s, All is good!

Don't quote me on this but with some horse power changes the cam key must be changed yours my be one of these!

Why yes, yes I could!

See Chuck No Problem there! Were here for ya

BUD !

Sounds like all those EGR problems paid off for someone! Somewhere in the back of my head I hear Dave Chappelle....

I think fjh is probably on the right track, especially if '68 checked that boost relief valve out recently.

yup that guy made enough money to take a Vacation! Why don't ya drop

up my way Chuck I need a vacation! How bout you Rass ? you could use a week in the Sun couldn't ya!

the correct way to check egr is to unplug it ????????????

If you unplug it it will code out!

The valve is controled by the flow in the mass flo tube the valve really only goes where its told to go the computer does not know if its getting there or not!It would show up on the advance display in diagnostics as not reaching target but won't throw a code for it!

put the block plate in, that 68 made ya and try it!

If it is the egr valve your floating boost will be gone!

Hey can you guys explain how to put a puff limiter bypass switch in a 1989 E9. We have smoke tests up here, so i dont wont to remove the system, just get around it? Is there a advantage, power wise with a bypass? I came along in the VmacI era, so not really skolled in the gaurd. bobo

simply put an air switch on the supply line to the limit relay

thanks.....

Casting sand from when the engine parts were made. This was a problem with the early E-Tech engines. The fix is to fabricate a new line and run it from the compressor inlet to one of the plugged holes on the water manifold.

Hello all, I recently had the injector pump on our 89 E6-350 rebuilt and while the issues that caused me to get it rebuilt have been resolved, I now have a new problem. When I release the throttle pedal, the engine rpms quickly drop to 900 rpms, from which point it slowly drops the rest of the way down to the idle setting of 650 rpms. This is preventing the Jake brake from actuating when it should and I wind up coasting for anywhere from 5 to 20 seconds before the Jake kicks in. Also, if the road is at all rough the Jake seems to "bounce" on and off as the rpms slowly reach idle. I brought the truck back to the pump shop and explained the problem to the "technicians" that rebuilt the pump and they refused to even entertain the idea that there was a problem with the pump, telling me that not only would they not go for a ride with me so that they could see exactly what the problem was, but said that the problem was electrical, a bad clutch or pump switch for the Jake and would do no further trouble-shooting until I had replaced both switches. Despite the fact that I knew full well that the switches were good, I changed them out for new ones, thoroughly examined the throttle linkage for any symptoms of binding, increased the throttle return spring tension and ........same problem. I now have the idle stop backed about all the way out, using the jake switch as the idle stop and it works a little better but still is not right and I am at a loss as to what I should do next. Any and all ideas, thoughts or suggestions on this are greatly apreciated,sorry for the long winded post, Thanks, Rick

By the way, its a PLM pump with an Ambac govenor.

It looks like you used the old lever,

Replace the throtle lever on the side of the pump if the springs re worn it will surge and not return correctly!

ok i just went through the procedure again and all was correct gona put some antifreeze in her and crank her up thank you for the info.god bless ed

Anytime!

Sorry I missed your post been busy !You need to find the valve set marks on the fly wheel peep hole at the bottom, also your engine will have a slack spot where the

dynatard lump is I beleive there is a small depression at that spot to allow the slave in the rocker to charge

your probably landing on that spot,Seting on valves rocking is not the best on these engines.

Yup thats normal as I explained The dynatard will make some valves appear loose your good to go!

hello again just wondering if anyone could help me out here.thx

Sorry I missed your post been busy !You need to find the valve set marks on the fly wheel peep hole at the bottom, also your engine will have a slack spot where the

dynatard lump is I beleive there is a small depression at that spot to allow the slave in the rocker to charge

your probably landing on that spot,Seting on valves rocking is not the best on these engines.

I've driven quite a few Macks with Allison Automatics and been very happy with them. They provide a very smooth "take up" of power when starting that seems to reduce wheelspin and the chance of getting stuck. With the new electronic controls they don't seem to end up in the wrong gear at times like the old ones did, and even if they do you can just press a button and override the transmission's choice of gears. As for the Volvo automated manual that Mack is offering, it has potential but it's reliability is still an unknown and Mack isn't offering it in a vocational model. Stay away from Eaton's automated manuals- in low speed operation the clutch slips and wears out prematurely.

Apparently the M/V Drive trans has been a staple in Europe for years ,

having said that I to am a doubting Tom,

here is an update on the situation got back to the shop started truck ran good for the first five seconds started to go under a load cracked the injector line for number cylinder number one, engine ran smoother cracked number two heard a distinct cutout, switched pumps between one and two did not help the situation problem has been narrowed down to number one cylinder removed wires from pump checked for an open circuit on the wires it was open leading me to believe that it is a mechanical problem. in the cylinder or in the injector seat or in the line fittings if they are cracked i am also going to pressurizd the radiator and start it to see if there is any white smoke out the exhaust. Is there anything else that should be checked out?

You had a code for no#1 EUP Which is now in number two! Correct? You need to put that origanal no 2 pump back in its hole as it is calibrated for that hole and either replace the eup or replace the injector!Remembering you had a code for #1 eup.

My opinion!

just saw your post I'll give you a call here in a minute, dog chewed my laptop power cord so no internet at home. I hope it shocked the little SOB!

You need to feed that dog more!

The injectors have been replaced as that was thought to be the issue by shorting out the pumps will that act like loosening the injector lines on mechanical engines Sorry if i ask some redundant questions but i am 19 and have a far better understanding of cat engines and equipment looks like a very similar system just want to learn more about it never know when it will come in handy

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Yupper , Same as loosening a line just not as messy If you identify number 1 as the culpret change the eup if you are sure that the injectors are fine !

Or if the problem persistsOR it is not No #1 I would pull the pan and and check thew ristpins on the one you do find!

My opinion

I am dealing with a 2000 etech with 230000 that on cold start has what sounds like timing knock or firing early when the engine warms up it can still be heard just not as loud. the driver said the sound a year ago was not very loud it has been progresivly getting worse i remember reading some where that mack had problems with there cams i removed the pumps and looked over the cam there was nothing wrong with that the injectors were replaced as to a thought that this might be a problem i am at a loss were to look it brings up a code for cylinder number 1 abnormal frequency any thoughts or sujjestions would deeply be apreciated

It may be a bad injector

To check which hole breifly short out each unit pump one at a time untill you hear the knock go away. If you find its,eup 1

Replace unit pump one! But note the cal code on the side of the new pump as it needs to be installed in the computers brain at a later date by a Dealer..\

It may be a bad injector

Also check the pan plug for brass I have seen several trucks of this era with the odd bad wristpin bushing.

everything was going great, took off this morning, low boost rite off the bat.

no badass locamotive sound. no boost all day, 20psi. some times 25psi for a few seconds then back to 18 or 20

JB HUNT was telling me to get out theway..

hope you got a rabbit to pull out of your hat mackpro????????

Chuck give the EGR valve a tap with a small hammer see if that wakes it up any!

I wondered when I saw your post as you are creating the same situation as pluged cooler with a block plate!I bet the egr valve is sticking open.Have 68 put the truck on the advanced display in the OLD VMAC PROGRAM It will tell ya where the EGR valve is at If its a more than 50 % its stuck open.The other possibility is the turbo vanes are jaming or linkage is sticking!

That is what was on this filter housing when I got it. I need to pull the dash and see if I can change the fitting on the back of the gauge(if I can't find parts to fix the copper line).

Good find Originally on most of the R models the trucks came plumbed with 1/4 braid from the filter head to the fire wall then plastic to the gauge head I hope ya got the fix there,Kinda bad timimg for a burst line.

Yup, same pictures in my book. I matched the existing gasket when I got the new one. I then installed it while matching up the ports. I see the note where the "tab" is on the right side. Guess tomorrow I'll make sure it's correct.

I had dreams about this happening.................and sure enough.....grrrrrrrrr.

I gave the bracket to the parts guy to get the proper filters for it in hopes that would go right.

Train I haven't followed what you have done to this engine other than the housing so forgive my ignorance !BUT there is somthing I ran across some time ago , have you looked at the compressor I ran across one of these that the compressor had babit ( WORN )style bearings on the crank and it caused the engine to have low oil preasure.

Thats good to know. I have to see this week if i can swing it. What is the rebuild point on these motors. I know 500k give or take is a lot on a dump truck.

I have seen em go 30000 hours in a dump application

look at the hours not the miles You can easy see 20 -250000 on average .

Tell me what you know about the 454. Im looking at a 1996 CL with a 454 in it. Tri/axle dump truck with around 500k on the motor. I know the 1st owner and the 2nd. The truck always got what it needed. So whats the deal with the 454?? Good motor, Bad motor?? Thanks

Good engine ,the best model of truck to have , Last of the stand up oil changes!.

We could have filled a 5gallon bucket with all the soot we cleaned out of that EGR cooler. About the worst I have ever seen. Buts as long as it's dry power and not caked in there we are good. Next on the list is a air compressor as its pumping oil like crazy and we will change the air drier filter as well. I was glad to have an ASET to work on today as it was the only non-MP engine in the house. The MP's were dropping like flies today. Glad you made it in today as tommorrow I will be at another Zoo, StLouis Zoo that is with the wife and kids.

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Its funny How things go ! We've had a influx of clutch jobs in last 6 months it seems like one or two a week! The MP'S are Holding up Well in our area for the time being, aside from the normal dpf problems ,( touch wood) New trucks are finally starting to sell again so stuff should start to happen again!

We have 4 MP10 running about no real problems with them YET Time will tell.