87 Still doggy low boost need more ideas. - PeachParts Mercedes-Benz Forum

ngarover · #1 11-30-2013, 04:16 PM

Again, this is on my 87 300D. Om603. New head. (another 14) New water pump. New Injector lines. pop tested injectors.

ok, so I have removed the turbo and checked it, spins nice, no play, waste gate operates as it should, starts to open at 15 fully open at 25. (checked with Mighty Vac).

Car shuts off instantly when you turn off the key.

Slight bounce to the stop lever, better now that I've replaced the IP lines but still there a little. Checked the pod controlling it and it's fine. held 15 pounds for over an hour. Would have held indefinitely I believe (again with Mighty vac).

Boost is about 2-3 pounds max. Via gauge. Car feels like it has 50 horse power.

I have check the timing and IP timing. both are right on the money. Car starts up immediately.

Replaced the filters. Only one I have not looked at yet is the one in the tank. Had the return line off for a sec to fill up the new filter and fuel pours out. So would seem to be fine.

Checked the linkage for the throttle. all seems right.

There is no ALDA.

Idle control does work correctly. Tested it also.

Kind of running out of ideas. here.

This is video of it before replacing the big fuel filter. made no difference.

https://www.youtube.com/watch?v=0Ui5tp_8D68&feature=c4-overview&list=UURVFXzT15ul-o6ip0TNmBtg

Just ran out and shot this quick video of it. I take it for a drive and show you the boost etc. Might take a bit for it to upload and process.

http://youtu.be/i5U2Xq1mAnw

winmutt · #2 11-30-2013, 07:40 PM

You verified the wastegate ya? Check for boost leaks and failing that take a rod to the cat (which you should do anyways). Are you hitting the max fuel stop on the eng side of the IP? Look for a hammer to come up and hit a nut as the pedal goes up and down.

ngarover · #3 11-30-2013, 08:12 PM

I verified the waste gate buy hooking up the mightyvac to it. found it to start opening at 15 and fully open at 25. I was correct in the bar being bent, which I fixed while I have the turbo off.

Have my oldest daughter sit in the car and work the gas peddle. linkage seems fine from what I could see.

Going to try the bottle trick tomorrow and run the car to see if there is any issues in the lines or filters.

ngarover · #4 12-01-2013, 05:02 PM

ok, spent time this morning with this image...

Found a few issues.

1. I don't have the ALDA anymore. But the nipple from the intake to Y30 was on the top not the bottom like in the diagram. I tied the top to the bottom of Y29. because of the lack of ALDA.

2. Line 61b (vac going to key shutoff) was Y'd to 61A. Corrected that.

3. Then I started to replace all the factory hose clamps on the fuel lines. 3 of them would turn even screwed all the way down. In the process I discovered that the return fuel line is crappy. literally fell apart when I went to take to off. So I'm off to the parts store for that. Fixed.

4. Opened the tank and there was a whoosh. Removed the Tank vent and cleaned it, then tested it. It tested good so I replaced it.

5. Found a nicked spot in the hard line. After I released the vacuum in the tank, the line started to leak... So I cut it and repaired it with a brass compression fitting.

6. was about to test drive, so went to close the hood and it would not latch...sigh. Looked at it and it seemed the latch was not going fully back into it's correct position. took a flashlight and looked at where the line meets the latch outside... and what do you know. it was broken, and someone had used 2-4 zip ties to hold it all together. Grabbed the one off the 94 and replaced it the correct way.

7. ran the car, bled the lines, I had pretty much taken a bath in diesel at this point fixing the leaking hard line. (yes I did drain the tank)

Took it for a drive and sure enough it had a little more power. Turbo would spin up to 6. Tomorrow I'll drive it into work with me and when I get off, take it over and have a straight pipe put on. I did separate the exhaust and took a look at the (cat) tried to jam a bar in there a few times but no real luck.

tjts1 · #5 12-01-2013, 05:07 PM

Quote:

Originally Posted by ngarover

I verified the waste gate buy hooking up the mightyvac to it. found it to start opening at 15 and fully open at 25. I was correct in the bar being bent, which I fixed while I have the turbo off.

I'm confused. Are you applying pressure or vacuum to the wastegate actuator? It should be start to open around 7-8 psi of boost.

ngarover · #6 12-01-2013, 07:45 PM

Quote:

Originally Posted by tjts1

I'm confused. Are you applying pressure or vacuum to the wastegate actuator? It should be start to open around 7-8 psi of boost.

Off top of head I forget. I had the whole thing off the car when I did it. Which ever though, it would start to open at 15 and would be fully open at 25

rscurtis · #7 12-02-2013, 09:51 AM

I would assume it was vacuum. No way can a MightyVac develop 25 PSI.

vstech · #8 12-02-2013, 10:32 AM

I was under the impression that the 87 wastegate is pressure operated... no?

be REALLY REALLY CAREFUL mashing up a diesel cat!!! the powder in there will KILL YOU DEAD... really bad burns on your skin from the powder too... do not inhale that stuff.

ngarover · #9 12-02-2013, 05:55 PM

OK, so took the car over to a shop and cur out the cat. 25 bucks later, it's gone and the car runs a lot better. Getting closer...

87 300D - YouTube

In the video, keep in mind that due to the 205 tires my Odometer is off by 10 MPH (too slow) So if it says 40. I'm really doing 50.

Here is a picture of what the inside of the car looked like.

ngarover · #10 12-02-2013, 06:01 PM

Quote:

Originally Posted by vstech

I was under the impression that the 87 wastegate is pressure operated... no?

be REALLY REALLY CAREFUL mashing up a diesel cat!!! the powder in there will KILL YOU DEAD... really bad burns on your skin from the powder too... do not inhale that stuff.

Good to know about the cat!!!! Should sticky something like that.

tjts1 · #11 12-02-2013, 06:46 PM

Quote:

Originally Posted by ngarover

Off top of head I forget. I had the whole thing off the car when I did it. Which ever though, it would start to open at 15 and would be fully open at 25

Quote:

Originally Posted by vstech

I was under the impression that the 87 wastegate is pressure operated... no?

Yes it is, something doesn't make sense here. You can't test the wastegate actuator with vacuum. It needs positive pressure in order to open. The maximum boost pressure on the OM603 should be no more than 15psi and in most cases around 12psi. The WG should be fully open by 15psi and fuel cut off kicks in at 17psi.

ngarover · #12 12-02-2013, 07:32 PM

Quote:

Originally Posted by tjts1

Yes it is, something doesn't make sense here. You can't test the wastegate actuator with vacuum. It needs positive pressure in order to open. The maximum boost pressure on the OM603 should be no more than 15psi and in most cases around 12psi. The WG should be fully open by 15psi and fuel cut off kicks in at 17psi.

I tested it multiple times, mainly because the rod was bent enough that it was stuck against the bolt. Each time was exactly the same 15 open to 25 fully open.

It's easy enough to do it again on video, it's raining now so in a couple days I'll do it and add the test to the thread.

After getting the cat removed, I also notice that the turbo is now boosting a constant 7-8 at 65. I saw it peak at about 15 going up sand mountain, holding second. so it would seem to match where the waste gate opened for me in the test. It's really hard to say whats been done to the car in the past. I have a pile of receipts on it 2 inches thick from when I bought it, and since then I'm done a ton to it, but this is the first time I have touched the turbo itself. Now that I have it fueling right, the next step will be to start upgrading a few things... I've riden in Winmutts car... I know what I want now...

vstech · #13 12-02-2013, 07:39 PM

Quote:

Originally Posted by ngarover

I tested it multiple times, mainly because the rod was bent enough that it was stuck against the bolt. Each time was exactly the same 15 open to 25 fully open.

It's easy enough to do it again on video, it's raining now so in a couple days I'll do it and add the test to the thread.

After getting the cat removed, I also notice that the turbo is now boosting a constant 7-8 at 65. I saw it peak at about 15 going up sand mountain, holding second. so it would seem to match where the waste gate opened for me in the test. It's really hard to say whats been done to the car in the past. I have a pile of receipts on it 2 inches thick from when I bought it, and since then I'm done a ton to it, but this is the first time I have touched the turbo itself. Now that I have it fueling right, the next step will be to start upgrading a few things... I've risen in Winmutts car... I know what I want now...

... in the first part of your post, you are stating VACUUM 15-25 is opening the wastegate...
in the second part of your post, you are stating you are measuring 7-8 PSI and peaking around 15PSI and saying it's matching wastegate measurements...

zorecati · #14 12-02-2013, 08:44 PM

The video quality is piss poor, but you'll get the idea. My car is stock except for removing the vacuum lines from 60 and 137b in the diagram. I can take a better video if you like. Judging from what i've been told is a solid 0-60 time, mine seems to be running pretty well. I think I timed it at about 11 seconds. I could probably do a bit better if I preloaded a little.

87 300d 0 to 60 - YouTube

vstech · #15 12-02-2013, 09:30 PM

I thought the 300D was capable of 8ish second 60 times... my wagon does it around 11...