1990 300 W124 2.5 Turbo Running worse after attempted Tune up - PeachParts Mercedes-Benz Forum

rocketboy52 · #1 06-03-2009, 03:49 AM

New guy here with lots of issues.
Did an intro post here discussing all my recent drama, but I'm still pumped to see if I can make this diesel a little sweetie.

Newbie Introduction -1990 2.5Turbo 300D

Long story short, haven't had the car for that long, less then a year and I'm going through her trying to get her to be a daily driver and road tripper for the Mrs. and family.

The car ran surprisingly smooth when I first bought her, but she was leaking fuel like mad.
I replaced the IP valve O-rings, and fuel filters and got the majority of the fuel leak fixed.
A few months later, the tranny is starting to shift a bit harder and the engine shakes violently after coming down from high throttle.
I read some threads on hear, I buy two cans of diesel purge, and a set of Bosch injectors from:

I ran the diesel purge, I install new injectors, I replaced the fuel return lines.
After all this "tune up" effort, the car misses when idling, but its not a constant miss, just a miss every 3 to 5 seconds the car will shutter and buck a little.
Sometimes it is worse then at other times, other times it won't miss at all for 5 minutes.

The car drives great on the freeway with no major issues, but has slower acceleration and hard shifts. I do 0-60 in ~18 seconds.

I'm not sure what to do next, any ideas?
The current plan is to put the old injectors back in and see if that does anything, as well as replace all the plastic clips that hold the injector hard lines in place.
Any other things I should try?
Thanks for the help in advance.

awsrock · #2 06-03-2009, 09:35 AM

Were the injectors that you bought pop tested? Or did you just swap them in? If they are all out of balance, you might be having issues because they timing is way off (i.e., not all injectors popping at the same pressure).

I think the 0-60 for a well tuned 602 is more like 12-13 seconds, so you are close, but still a bit off. Do you feel the boost coming on? A 5 second difference can usually be attributed to lack of boost.

Have you read about the wastegate issues that the 602 can have due to electronics?

2.5Turbo · #3 06-03-2009, 02:30 PM

Mine did 18 second 0-60's when the boost wasn't there. Make sure you didn't knock any lines or plugs off while working.

tbomachines · #4 06-03-2009, 03:08 PM

Is the wastegate on these engines vacuum accuated?

rocketboy52 · #5 06-06-2009, 01:18 PM

I thought the turbo is vacuum actuated? Not the case? I have a lot of reading to do still. I want to try and vacuum leak check the various systems, but the vacuum system is so ...everywhere in this car, I'm not sure where to even start. I figured I would try to troubleshoot the hardshifting tranny first, but in my readings of the various helpful threads, all of the say that I need to get the enigne running silky smooth first.

rocketboy52 · #6 06-06-2009, 01:21 PM

Quote:

Originally Posted by 2.5Turbo

Mine did 18 second 0-60's when the boost wasn't there. Make sure you didn't knock any lines or plugs off while working.

By lines are you saying fuel and glow plug lines? The engine runs good at higher RPMS, but at idle, I think I idle around 700 rpm, the car misses once every 7-10 seconds and causes the car to shudder. ...I'm going to put my old injectors back in as soon as I finsh this post and see if it is better or worse after I swap the oldies back in.

rocketboy52 · #7 06-06-2009, 01:27 PM

Quote:

Originally Posted by awsrock

Were the injectors that you bought pop tested? Or did you just swap them in? If they are all out of balance, you might be having issues because they timing is way off (i.e., not all injectors popping at the same pressure).

I bought Bosch injectors off of ******.com. Are you saying that right out of the box, they need to serviced? I figured that when you buy new injectors they would be set to some default spec value. I just installed and ran them. I guess I've got a lot to learn about diesels.

Is it worth it to try and set up my own pop testing rig, or better to just have someone who does this all the time do it? Anyone online that I you all recommend that I can send a set of injectors to? What does it cost to get a set bench popped?

Quote:

Originally Posted by awsrock

Have you read about the waste gate issues that the 602 can have due to electronics?

First time I've heard about this issue, any posts or threads you can point me to? A trouble I'm having with searching the threads, is that soo many of the threads have such generic titles, that even if I find something related to what I'm looking for, it will be for an older 617 diesel MB. Any tips on searching?

rocketboy52 · #8 06-06-2009, 01:29 PM

Quote:

Originally Posted by 2.5Turbo

Mine did 18 second 0-60's when the boost wasn't there.

Since I'm new to diesels, I'm not sure if I'm feeling "boost" or simply the car getting into its power band. Any way to know for sure if the turbo is working, and working well?

Skippy · #9 06-06-2009, 09:50 PM

If you plumb in a boost gauge and monitor it while driving the car, you will know for sure. Harbor Freight is said to sell a decent boost gauge for around thirty dollars.

t walgamuth · #10 06-06-2009, 10:28 PM

Don't forget the simple....air suck? ....bacteria in fuel?

I would suggest a biocide in the fuel for starters.

Diesel911 · #11 06-06-2009, 11:48 PM

Quote:

Originally Posted by rocketboy52

I bought Bosch injectors off of theBenzbin.com. Are you saying that right out of the box, they need to serviced? I figured that when you buy new injectors they would be set to some default spec value. I just installed and ran them. I guess I've got a lot to learn about diesels.

Is it worth it to try and set up my own pop testing rig, or better to just have someone who does this all the time do it? Anyone online that I you all recommend that I can send a set of injectors to? What does it cost to get a set bench popped?

I think the 0-60 for a well tuned 602 is more like 12-13 seconds, so you are close, but still a bit off. Do you feel the boost coming on? A 5 second difference can usually be attributed to lack of boost.

First time I've heard about this issue, any posts or threads you can point me to? A trouble I'm having with searching the threads, is that soo many of the threads have such generic titles, that even if I find something related to what I'm looking for, it will be for an older 617 diesel MB. Any tips on searching?

The situation with buying Injectors from a parts place is that they have a big Bin with 100s of Injectors in it. When they need 6 Injectors they reach in and grab 6 Injectors. So you have to view them as 6 individual Injectors.

The "default spec value" for the Pop/Opening Pressure of your Injectors is 135bar (1957.5 psi) to 145bar (2102.5 psi). So the Injectors that they pull out of the box can be anywhere in that range. That means there could be a difference of 10bar (145 psi) between the lowest and highest pressure of the 6 Injectors pulled from the Bin.

However, in the past the Factory has recommended that difference between the Pop/Opening pressures from the highest to the lowest Pop/Opening pressures on the Injectors on the Engine to be a max of 5bar (72.5 psi).

When Injectors from one Engine are rebuilt in a shop as a set they try to get that difference to be even lower. The 2 Member that rebuild Injectors for other member try to keep the difference to 3bar. (This can sometime be difficult to do as the Pop/Opening Pressure is adjusted by exchanging different sized Shims to change the Pressure Spring Tension; sometime you cannot find the right thickness of Shim you need to get the pressure you want.) They call this a "balanced set".

So what the other member was saying is that your chance of getting a balanced set from Injectors grabbed from a parts bin is slim and to take them someplace local and have the Pop/Opening pressures checked to see if they are balanced to each other.
A has a better potential to idle smoother.

The above being said the problem you are having may be from a tiny particle of dirt getting in the Injector or a defective sticky Injector Nozzle.
If you can do so while the Engine is exhibiting the problem loosen and tighten 1 Injector Hard Line Nut at a time.
If they Injector nut you loosen causes little or no change in the Symptoms; that is the faulty Injector (sometimes you can also watch the Engine RPMs on the Tachometer). If you loosen the Injector Line Nut on a good Injector it will have an immediate and obvious effect (the RPM will obviously drop). In fact Most of the good Injectors should have a similar RPM drop or produce similar Engine shaking when the Injector Line Nut is Loosened.

If you locate a problem Injector call or Email the Seller and tell them you have a Faulty Injector and I bet they will send you an Exchange

Diesel911 · #12 06-06-2009, 11:57 PM

Quote:

Originally Posted by Diesel911

The situation with buying Injectors from a parts place is that they have a big Bin with 100s of Injectors in it. When they need 6 Injectors they reach in and grab 6 Injectors. So you have to view them as 6 individual Injectors.

The "default spec value" for the Pop/Opening Pressure of your Injectors is 135bar (1957.5 psi) to 145bar (2102.5 psi). So the Injectors that they pull out of the box can be anywhere in that range. That means there could be a difference of 10bar (145 psi) between the lowest and highest pressure of the 6 Injectors pulled from the Bin.

However, in the past the Factory has recommended that difference between the Pop/Opening pressures from the highest to the lowest Pop/Opening pressures on the Injectors on the Engine to be a max of 5bar (72.5 psi).

When Injectors from one Engine are rebuilt in a shop as a set they try to get that difference to be even lower. The 2 Member that rebuild Injectors for other member try to keep the difference to 3bar. (This can sometime be difficult to do as the Pop/Opening Pressure is adjusted by exchanging different sized Shims to change the Pressure Spring Tension; sometime you cannot find the right thickness of Shim you need to get the pressure you want.) They call this a "balanced set".

So what the other member was saying is that your chance of getting a balanced set from Injectors grabbed from a parts bin is slim and to take them someplace local and have the Pop/Opening pressures checked to see if they are balanced to each other.
A has a better potential to idle smoother.

The above being said the problem you are having may be from a tiny particle of dirt getting in the Injector or a defective sticky Injector Nozzle.
If you can do so while the Engine is exhibiting the problem loosen and tighten 1 Injector Hard Line Nut at a time.
If they Injector nut you loosen causes little or no change in the Symptoms; that is the faulty Injector (sometimes you can also watch the Engine RPMs on the Tachometer). If you loosen the Injector Line Nut on a good Injector it will have an immediate and obvious effect (the RPM will obviously drop). In fact Most of the good Injectors should have a similar RPM drop or produce similar Engine shaking when the Injector Line Nut is Loosened.

If you locate a problem Injector call or Email the Seller and tell them you have a Faulty Injector and I bet they will send you an Exchange

Here are some pdfs on Injectors for your vehicle
602 test injectors
http://www.ps2cho.net/downloads/MB%20CD/W124/w124CD1/Program/Engine/602_603/07.1-6712.pdf
602 adjustin Injector Nozzles
http://www.ps2cho.net/downloads/MB%20CD/W124/w124CD1/Program/Engine/602_603/07.1-6750.pdf

compress ignite · #13 06-07-2009, 12:00 AM

All of their nozzles are "Manufactured" in India or Myanmar and the Q.C. is S**T

Contact member sean c watts about a set of balanced Monark nozzles installed
in your Bosch Injector housings.

Settle down in a quiet place for the weekend with lots of frosty beverages and
peruse this set of posts:Wastegate actuator swap for OM602.962?

This is not cruelty,just information...
1.If you R+Red your DV O-Rings in less than ABSOLUTELY sterile conditions you may have introduced contaminants into the DV system.
2.If you R+Red your DV O-Rings AND ALLOWED any of the INTERNAL DV parts
to ROTATE you have changed a "Lapped" relationship between the components.

rocketboy52 · #14 06-07-2009, 12:56 AM

Quote:

Originally Posted by compress ignite

Settle down in a quiet place for the weekend with lots of frosty beverages and
peruse this set of posts:Wastegate actuator swap for OM602.962?

I actually found this and have started reading through it (first couple of pages so far) and can't wait to do it! I figure I need to get the car running well with all of the normal issues figured out before I start modding the car. But its definately on my list of wants

)

Quote:

Originally Posted by compress ignite

This is not cruelty,just information...
1.If you R+Red your DV O-Rings in less than ABSOLUTELY sterile conditions you may have introduced contaminants into the DV system.
2.If you R+Red your DV O-Rings AND ALLOWED any of the INTERNAL DV parts
to ROTATE you have changed a "Lapped" relationship between the components.

I don't follow any of this last statement
"R+RED"...?

"DV O-rings"...?

I did replace the orings on the injector pump valves as they were hard and leaking. I was sure to only do one at a time and put all the lapped inserts in the same valve bodies so they weren't mixed up. I did clean all the valve bodies with break cleaner, and blew them off with compressed air and reassembled. I used a clean blue shop paper towl to handle all the clean bits before reinstalling them. Do you think this apporoach wasn't clean enough? Is that what DV-orings are?

Still in the dark on what "R+Red" is.