Turbo boost guage advice needed - Page 3 - PeachParts Mercedes-Benz Forum

Thomaspin · #31 04-25-2003, 04:25 PM

In here?

jbaj007 · #32 04-25-2003, 04:30 PM

Thomas, don't know all on the gasser gauge on the 86-89 revision; 90-91 revision. There are slight differences in the 126 for ea. of those time frames. I used a 1984? 380 SEL gauge section from the '81-85 time frame version of the 126. I have seen many others and the method (armature winding) and resistors of the fuel gauge part do look a little different on some of the newer ones, but I THINK they interchange.
PS: Hope you received (or should recieve soon) the parts info. I sent. Went out 2 days ago.

dculkin, Point well taken, but since my lines and switch over valve are pristine (tested and checked) I opted for the easiest to get to spot to add the parallel line since I am an inveterate "fiddler" and I throw a vinyl hose on the "gang" often.

Honus · #33 04-25-2003, 04:42 PM

Thomas, that is the location I had in mind, although I would defer to the more experienced people on the board. I was looking at my 1985 300D last night to pick a location for the tee connection and was surprised at just how small these pressure lines are. I guess the small diameter doesn't hurt anything because all these lines do is sense pressure, so there is no pressure loss like there would be in a line carrying an actual flow rate. It would be interesting to see whether a gauge connected directly to the manifold would show greater pressure fluctuations than a gauge at the location shown in your photo.

I just ordered an Isspro gauge which I plan to connect at the location shown in your photo. I think I will mount the gauge in the ashtray.

I also think jba's point is well taken.

Thomaspin · #34 04-25-2003, 06:57 PM

Jbaj007 - thanks. There's a nice 380SEL at the local wrecker - that might be a good match for my 1983. I'll let you know when the package arrives - thanks again.

Dculkin - thanks for helping me think this through. This location should disclose whether either the line or the switch are jammed (or the turbo is blown!)

Thomaspin · #35 04-29-2003, 11:43 AM

Thanks again for the tip - I have added a page to my transmission tuning piece and credited you with the suggestion here.

The Warden · #36 04-29-2003, 04:58 PM

Very interesting on the economy gauge idea...was the gauge ever put on 123 instrument panels?

Even if the 126 gauge part would fit on a 123 (I'm guessing not), I don't want to lose the mechanical oil pressure gauge...

Ridge · #37 04-29-2003, 06:13 PM

The gasoline 123s like the 280E and 280CE have the economy gauge and one of the guys out in the Bay Area who put a 4 speed 240D transmission in his 300TD rigged up the 280, 123 econo gauge as described here and it worked fine.

Ben

#38 04-29-2003, 08:19 PM

Thomaspin: your website is not Mozilla friendly - can't see anything but "e-mail" on the index page. Could you please post the url for the page explaining the econogauge?

thanks.

Thomaspin · #39 04-30-2003, 10:51 AM

I don't have the econogauge fix done - that was jbaj007's idea.

The location for measuring turbo boost is here if that helps.

My home page uses java for the menu - do you have java script enabled on your browser? What is Mozilla, by the way?

coachgeo · #40 07-01-2003, 09:58 AM

Quote:

Originally posted by dzldog
...
Also, why T? There are additional ports in the intake manifold into which the boost gauge line can be tapped.

Where are these ports?

#41 07-01-2003, 11:41 PM

I used the stock fitting from my chepo $20 boost gauge kit from pep-boys on the "plug" below the overboost sensor. It fit perfectly with no troubles yet!

coachgeo · #42 07-02-2003, 12:19 AM

Quote:

Originally posted by 82-300td
I used the stock fitting from my chepo $20 boost gauge kit from pep-boys on the "plug" below the overboost sensor. It fit perfectly with no troubles yet!

I was wondering if that was a port too? I posted that question on here some time back too actually.. Anyway.. glad ya said something. Now I know fer sur...

I pulled the alda banjo bolt out of the junker today while at the bone yard hoping I could put it into that spot. I snagged a Y off the junker too though, just in case.

#43 12-11-2006, 02:52 AM

Quote:

Originally Posted by jbaj007

I use one that IS factory.(and stealth!)

1. Take an old fuel/temp/ oil pressure/economy gauge section from a GASSER 126 and transplant it into the 126 diesel instrument panel!
2. Remove needle from economy gauge (remove STRAIGHT up).
3. Replace needle on the ultra thin gauge shaft from where it came, but place it with the needle pointing at ~10:00 o'clock position.
4. Rotate the needle CC and lift/ bend it over the left side stop pin.
5. What used to be the economy gauge (Bourbon type vacuum gauge) is now a boost gauge (Bourbon type pressure gauge).
6. Attach with appropriate hose to "T" in boost line or to the empty intake manifold fitting.
7. I attached the hose to an aquarium gang valve in the boost line to the overboost protection switch so that I could rig a parallel hose and shop gauge temporarily into the cabin in order to calibrate (by moving the indicating needle on the shaft of the former economy gauge).
8. Full travel (left to right) is ~16 psi after calibrating. (I run ~14psi full out uphill). FWIW

Any tips to removing the needle? I can't get the bugger to budge.

jbaj007 · #44 12-11-2006, 11:14 AM

The shaft that the needle hub is pressed onto is very thin, so "straight up" removal is important. I use pliers with tape on the jaws now.

Two spoons (with tape on the undersides) as "pry bars" on the needle hub have been used with success.

Be careful, but strong, and good luck.

2.5Turbo · #45 12-11-2006, 08:46 PM

Will that 126 gauge pod work with a '90 124 300D? Or are the electronics for the fuel/temp/oil pressure different?