If you have a lot of smoke when accelerating then turning the ALDA maybe 1/4 turn back cw may make it faster. Give it a try.

Your transmission should be 1:1 in final drive unless you have an overdrive. I haven't heard of any transmissions that are less then 1:1 in final. So you should be getting more then 58 mph. GPS doesn't give you an accurate speed unless you are going in a straight line, or so I've been told.

Turbo bushings may feel a bit loose, usually less then 3/64 or so isn't too bad. Plugging the hose to the wastegate isn't bad if you want to get maximum boost. That doesn't mean you will be getting maximum power though. It just means that the engine will die sooner. The stock IP can't provide more fuel then for about 140-150 HP or so. The excess boost will just cause more wear with no more power. Course that also assumes no smoke. There is also the higher EGTs to take into account with higher boost and more fuel. You do have an EGT gauge right? It isn't really a good idea to go turning things up without an EGT gauge unless you have a lot of money burning a hole in your pocket. More boost and fuel means higher exhaust temps which also means higher cylinder temps and even the oil cooled pistons in the 617 can only take so much. I think the factory limited the boost to about 9 PSI and a lot of people have turned things up to about 12 without much problem. Then there are the crazy Finns I think it is who get somewhere north of 450 or more HP out of our 617s. Don't know how long they last at that though.

Anyway that's probably more then you wanted to know so I'll shut it down for now. :-)

well thank you very much that summed up quiet a bit. I wish I knew how much hp my motor was putting out, I just assume it feels slow to me because i was used to my 190hp v6 over roughly 120hp now. With the fuel turned up a quarter turn i have the line plugged off for more boost, because I thought more fuel needed more boost.

Would adjusting the valves help performance at all?

Adjusting the valves won't hurt performance but you will mostly notice it in starting. If it's hard to start when real cold then valve adjustment could be a problem. Valves should be adjusted every 10,000 miles according to MB but I haven't had any problems with adjusting at 20,000.

Here is some more info on the ALDA from my notes that I got from a bunch of different places.

After adjusting your ALDA up and you notice substantial power gains, like most of us do.... If you then disconnect the ALDA pressure line, and have no noticable difference in performance (it stays strong under

boost) your ALDA is over adjusted. Too shimmed up or too cranked CCW. Or the ALDA could just be shot (stuck in position).

To tell if the ALDA is shot...

If you blow in the nipple and the pressure pad moves downward (out of the hole), or does not move at all, your ALDA seal is shot. It should move into the ALDA.

If air escapes from the actuator area as you're blowing into the nipple, your seal is shot.

If it rattles when shaken lightly, your seal is shot.

When your seal is shot, the ALDA performs no effect or perhaps even the opposite effect of what it's supposed to be doing. ALDA *requires* a good seal to work because it needs an atmospheric pressure reference maintained inside the case.

To add a boost gauge you could just T into that line from the pressure limit valve to the ALDA. BTW it is a good idea to have that pressure limit valve in there it only shuts down at about 16 PSI, a good maximum safety pressure.

OH, to do the tests you do have to take the ALDA off.

im assuming my ALDA actually does work because originally I did not have that line from the intake manifold to the ALDA at all. Then after some reading I hooked that line up and adjusted the ALDA all the way clockwise, the truck was so slow itd barely move haha. then I kept adjusting it CCW and it started getting faster but i did it in larger increments like 1.5 turns at a time and by time I knew it I was all the way maxed out again but it does take off much better from a start.

First thing you want to check is the valve adjustment, then do a compression ck. If all that checks out ok then it's a fuel or air problem.I advanced the IP timing to 26 deg on mine and it made a huge difference. If your timing chain is streached it retards timing. You may want to check or replace the injectors. Make sure there is no exhaust restriction or intake restriction(those ricer cone filters can restrict air).

I think my exhaust may be restrictive due to it being only like 2-2.25 right at the down pipe after that it opens out to 2.5", also I do have a cone filter on and i need to relocate that due to it being directly on top of the turbo. also where is the best place to mount an EGT sensor and how hot should it be casually driving around?

Normal driving about 1000 or so highest temp hauling a load uphill I wouldn't let it go past 1250 or so. That's before the turbo. After the turbo the temps are lower but due to load and engine speed it varies too much to say keep it xxx degrees below the inlet temp. to me it's just a curiosity.

Locate the gauge wherever you want. It would also be a good idea to put in an audio warning buzzer (a loud one) at 1275 deg.

sorry i guess the EGT sensor was a bad name to call it, I was wondering where would be a good place to drill and tap for the probe.

Naw not a bad name for it I was just not paying attention when I was reading.

The best place is in the collector just before the turbo. Some people don't like that because if it's a cheap probe it could break after a while and trash the turbo. But if you put it after the turbo you can't get a reliable temp reading, in which case I wouldn't let it go above 1000 deg just to be safe. Heck even then it is still possible that you could be reading up to 500 deg below what the inlet temp is. When you think about the cost of rebuilding an engine with melted pistons vs rebuilding a turbo I'd take the turbo any day. Remember over temp damage is cumulative. The little bit of melting on the piston top each time will not cure itself and then it's big money time. Then again I guess there are still a lot of 617 engines around to be bought rather cheap :-)

Sounds good, thank you also I was wondering what temp does your motor noramlly run at? i plaeced my sensor on top of the thermostate housing where the original one wnet but i had to make an adapter so it sits up a bit higher than the stock senor and the probe is not directly in the coolant. I was thinking since its is a pressureized system that it shouldnt matter, but my guage reads that it only gets up to about 165 on a normal day. Today it is very hot out and the gauge got up to about 190-210 and im wondeirng if the motor was starting to over heat because it randomly died on me once.

another option for those water sensors is to tap one of the side sensor block plugs.
the stock mercedes has something like 3 on the side, and another 3 at the thermo housing :nope:

tapping the side seemed easier then going w/and adapter or taping the thermo housing.


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hmm the only thing about that is on mine i am pretty sure that the electrical wire that connect the glow plugs run to that little sensor. im just not sure on how hot my motor should be running, because I only have 1 electric fan and im 99% sure the thermostate was a 190 thremostate so shouldn't the temp be closer to that at all times?

also on top of the injection pump where the hard lines go it I noticed that it is leaking fuel around there, I tried to tight the fiting but they seemed very tight. I there a seal that is in side that can go bad? It doesnt look like its spraying out but it is wet around it.

Mine all (3) run at about 190 in the winter here in Florida. I did put in a 193 deg thermostat in all of them. In the summer with AC on they go to about 195-198. If yours is higher, especially with your temp sender not right in the water stream then two things to think about. First is the radiator might be too small and the second is that the fan might not be pulling enough air. That would only count around town though. On the road the fan shouldn't even come on. Any speed over about 45-50 the air flow should be enough, with a properly sized radiator, to keep the engine well within temp.

On the weeping on top of the pump. There are no seals on the hard lines themselves, they are flair fittings just like brake lines. The fittings they screw onto however do have copper seals. The bad part about that is that if you start messing with them it can warp the top of the pump and cause exactly the weeping that you are seeing. Some people have rebuilt the valves and springs in there and done it well enough to cure the leak. Others have tried and not only didn't they stop the leak but in some cases made it worse or even caused the pump to go out of time. What I was told is that there are two parts to the fitting and if the bottom part is turned it causes the final timing of the injection to get out of sync. There is an adjustment there that compensates for minor differences in the individual pump injection pulse timing to each cylinder. I always figured that if it happens to one of mine I will just get the pump rebuilt by a shop and be done with it.

Hey Vette , you have to get your tach from off the alternator. Doug