Just bought a 1991 300D, help needed.... - Page 3 - PeachParts Mercedes-Benz Forum

Dizel602 · #1 11-12-2014, 12:17 AM

Ok, I believe I resolved the power issue tonight and all i did is I took off the electric plug on the switch over valve, unplugged it i guess....the car feels night and day difference. I had to drive it with 50% throttle most of the time and floor it getting on to the high ways and pray to get up to speed and right now I'm just barely using the throttle and power is more then adequate, tranny shifts even smother if that's possible, the car just feels 100% better.

Since i bought the car i filled it up 3 times and on all 3 fill-ups i averaged 10.4l/100km. Now with the proper boost should i expect to see increase in fuel economy?

JamesDean · #2 11-12-2014, 09:43 AM

10.4l/100km is roughly 22 MPG US I believe..

My 91 300D will do 30-35 MPG on the freeway.

Dizel602 · #3 11-12-2014, 11:43 AM

Quote:

Originally Posted by JamesDean

10.4l/100km is roughly 22 MPG US I believe..

My 91 300D will do 30-35 MPG on the freeway.

Yes it sorry for not posting a MPG figure as well. what should i expect in the city 26-28 MPG?

shertex · #4 11-12-2014, 12:48 PM

Quote:

Originally Posted by Dizel602

Yes it sorry for not posting a MPG figure as well. what should i expect in the city 26-28 MPG?

Fuel Economy of the 1991 Mercedes-Benz 300D 2.5 Turbo

JamesDean · #5 11-12-2014, 12:24 PM

I would say so. Its hard for me to say since 99% of my driving is highway.

dieselbenz1 · #6 11-12-2014, 07:12 PM

I just filled up and I calculate 32 mpg in US gallons all city driving but mostly freeway average speed 80 km/ hr and I'm light footed. 1992 - e300d turbo 602.9

Dizel602 · #7 11-15-2014, 10:42 AM

I replaced my delivery valve o rings last night and copper washers. The engine runs fine, idle is stable and doesn't smoke but i have a really loud knock now. Before i changed it it's almost like i could only hear 1 injector knocking and now sounds like its all 5, I this normal and should it go away by its self after a little driving?

jbach36 · #8 11-16-2014, 09:17 AM

Tank filter will reduce proper fuel delivery.

16vjohn · #9 11-17-2014, 10:33 AM

Do the wastegate swap, man. It's the first thing I did to my 300D. It's really not that bad. It's not hard to do with regular metric tools The hardest part is getting that damn retaining clip back on.

JamesDean · #10 11-17-2014, 10:36 AM

Quote:

Originally Posted by 16vjohn

Do the wastegate swap, man. It's the first thing I did to my 300D. It's really not that bad. It's not hard to do with regular metric tools The hardest part is getting that damn retaining clip back on.

The clip that connects the actuator arm to the wastegate?

I lost mine

Replaced it with a paper clip lol!

16vjohn · #11 11-17-2014, 10:42 AM

You know, I lost mine too.

However, on the replacement actuator the arm was solid and would only go in and out. Unlike the stock actuator that would flop around as it pleased. I decided to try it without the clip and it doesn't come off. I've been meaning to buy another clip. When I do, I'll remove the splash guard and sit my magnetic tray underneath the work area. I'll be damned if I lose it again.

It probably doesn't even matter, but I know it's not there and it drives me crazy.

Oldbeaver · #12 11-26-2014, 04:12 PM

Quote:

Originally Posted by Dizel602

Hello everyone,

About a month ago i picked up 1991 300D with 280km on the clock and ever since i have been reading around the forum to more understand these cars and their common issues and how everything works. I'm having the much so common problem of the car being under powered, 0-60 around 23 sec. So far i have replaced the air filter, main fuel filter and inline filter. The car starts with no issues, idles nice and doesn't smoke

When i brought it home i noticed that the vacuum line going from the waste gate to Y31/2 vacuum transducer was plugged with a golf tee which i unplugged and connected to the transducer. After driving around like that for a few weeks i decided to plug it back today and see what happens. The car had much more power and was a lot quicker but the tranny shifted like crap, harsh shifts, jerky and clunky at times. When i plugged it back again the shifts were really nice and smooth but reduced power??

I posted a few pics so that the experts get an idea what i bought and how it looks

This line was plugged with a golf tee...had power but harsh shifts.

I have a similar car, a 1993 300D turbo. As the issue you mention is of high interest, you did very well to ask here and to include pictures. I would like to learn from yr experience. However, you show a general picture of the engine where I cannot locate the problem you are highlighting.

Can you please mark the place of the "Tee" in the engine? I don't see it in your pictures. Want to locate that in my car too!

Thank you much.

Oldbeaver

Dizel602 · #13 11-26-2014, 11:09 PM

Quote:

Originally Posted by Oldbeaver

I have a similar car, a 1993 300D turbo. As the issue you mention is of high interest, you did very well to ask here and to include pictures. I would like to learn from yr experience. However, you show a general picture of the engine where I cannot locate the problem you are highlighting.

Can you please mark the place of the "Tee" in the engine? I don't see it in your pictures. Want to locate that in my car too!

Thank you much.

Oldbeaver

The golf tee was plugged in that line in the middle picture where you can see my fingers. Plugging that line back to the transducer helped with shifts quality, before when it was plugged with a golf tee the shift were very harsh.

How ever i solved my boost problems simply by unplugging the electric plug on the switch over valve and im happy with that at the moment. i am now running 0-100 at around 15 sec where before it was 23+

The only other issue that concerns me at the moment is my fuel millage. I changed the o ring and copper washers on the delivery valves and replaced my fuel return lines and i am still getting around 23 mpg or 10.5L/100Km which is 90% city driving.

I did a Diesel Purge as well and didn't notice anything after except that my injector #5 in nailing now. I added some Stanadyne diesel additive and i noticed that the nailing is slowly getting quieter and going away i guess....

dieselbenz1 · #14 11-27-2014, 10:09 AM

Fuel mileage and timing are related. Maybe time to check your chain streach and set your timing. Also maybe time to service your injectors.

Dizel602 · #15 12-02-2014, 10:13 PM

Quote:

Originally Posted by dieselbenz1

Fuel mileage and timing are related. Maybe time to check your chain streach and set your timing. Also maybe time to service your injectors.

I haven't had a chance to check the timing chain stretch as it has relatively low millage, 170,000 miles and "i think it's ok" so ill hold of till i get a chance to do it, but i did notice that the car almost always runs cold, the needle on the gauge newer goes past second line above 40c mark. if i push it hard around town it will get up to 80c but come right down if i'm easy on the throttle or stop on the lights. Could the engine running cold be causing my bad fuel millage?