Hi-
Though I really like my 1978 240D, I'm concerned about how low the power is when traveling in town, especially during merges. I looked around on this forum to see if there are any practical power modifications, and it looks like there are three things that have been talked about.

I saw that turbo-ing can be pretty successful, but it seems like this is venturing on a huge amount work, and to be honest, I don't think I have the skills to do that.

Another thing is the ALDA. It seems that you can "turn up" the ALDA to give the engine more fuel to work with, but it seems that in most cases that there isn't much adjustment that can be made. If I understand correctly, the ALDA is really just an altitude compensating device, and isn't really intended to be adjusted.

I've heard that you can replace the standard injectors with Monark injectors with higher flowing nozzles. Is this really a reasonable option, or is this just a good way to make your car double as a smokey crop duster?

Should I perhaps check things such as linkage to make sure that I'm getting full travel out of the linkage? The car has had a recent oil change, but the fuel filters have only been replaced once since I've had it (which has been about 12,000 miles).

Any suggestions? I know that it isn't a Formula One racer, but I was hoping that there's a reasonable way to get some more power out of it. I was thinking that if the car had about 15 more horsepower then it would be quite drivable (not that it isn't drivable now, it's just slower than I'd like).

Thanks!

Start with the basics, new fuel filters, valve adjustment, and throttle linkage check.

They only have about 62 or so hp, so they are pretty slow. You have to plan your moves way ahead of time in traffic.

__________________
"I was a dirty bird, Carol's not grungey - she's *****in" John Milner....American Graffiti

Thanks for your reply. It's probably been long enough that the filters should be changed anyway...

ALDA is only on turbo on engines, you have an ADA. Turning it "up", try it but not likely to make much differance.

Injectors, your stock ones flow very well. Even with a turbo and tuned up ip(injection pump) the injectors are still very good. If your injectors are worn, then putting new nozzles on will make it run better.

Basically do the basics, after that then you need to learn enough, or take it to someone who can help to set the ip a bit higher. Need to be careful about this as you can get really high egt's if you go to much, but a reasonable approach will give nice improvement in drivability. This is really the first step after making sure all else is in order.

I reamed out the pc burn holes too, this helped a lot after ip adjustments. This needs to be done rather carefully so as not to change the angle of the hole.

After these it starts to get a bit harder, make a new intake manifold, or add turbo.

__________________
1977 240D turbo

eastern virginia? where? i am near fredericksburg

__________________
1977 240D turbo

Edward Wyatt is on the money. Also check the cam timing and injector pump timing. Beyond that anything you can do to reduce back pressure and increase intake air will help some. Trying some form of ram air might help some

I know on the 300Ds and 300SD after a certain year (I think 82) they replaced the cam towers and cam to increase the valve lift. I don't know if they did that on the 240Ds however. It would be something to check into though.

__________________
green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

yes the newer 240's did get a higher lift cam, and differant cam towers. I think 81 is when they changed. I used an 83 to rebuild for mine. This is 10hp more then the 77/78

__________________
1977 240D turbo

Thanks for your guys' replies. Later this week I think I'll poke around under the hood and check the throttle linkage and the fuel filters, and see if there's anything obvious that's wrong.

47Dodge: Are you suggesting that a new set of injectors might help?

New injectors will help if the old ones are well worn, and not spraying well. But this mostly helps drivability, smoother idle, and better fuel economy.

__________________
1977 240D turbo

I've been talking to a friend of mine, and he was saying that people will sometimes install injectors from a 1.9 liter Volkswagen TDI engine. He said the problem with installing these injectors is that the injectors had to be adjusted in some way to "play nicely" with a 240D engine. Has anyone tried this?

Thanks.

You are talking about the AAZ injector which has two stages, first pops at 150-190 bar, the second pops at 300 bar.

From what I can tell, these injectors require a very fast pressure curve to pass from the primary injection, (190 bar) to the main injection (300 Bar) very quickly. You will read that the members who have put the AAZ injectors on their 617 say the engine runs quieter, but there is a loss of bottom end torque. The loss of torque is due to the retarding effect of the higher main pop pressure, the 5.5mm elements just can’t maintain the high pressure after the injector pintle lifts for the primary stage. The AAZ injector pump has a 10 or 11mm element which can maintain the pressure and volume throughout the duration of the injection cycle.

IMOP not a good option for your end goal.

hmmm, I wouldn't discount the need for a new timing chain either. A new chain wouldn't be a bad idea anyway if you have no idea when, if ever it was "re-newed", having learned the hard way they can and do break sometimes, often with catastrophic results, I'd give it some serious thought because a new chain can improve performance and fuel economy at least to some degree. Just my 2c...

Thanks for your guys replies. I did an oil change a couple days ago... And I was amazed at the difference! I knew that it needed one (I last did it in the fall I think???), but it apparently needed it a lot more than I thought... The car is smoother, quieter, and most surprisingly, faster!
Seeing how much of a difference a simple oil change made, I'm wondering what kind of difference just doing "advanced maintenance" would do.

OM616: Thanks for your reply. I've been reading on the forum, and it seems that unless you're ready to re-engineer the whole engine, you have to be careful with what modifications you do...

gear-head: My Mercedes-savy friend has been saying that I should check the timing chain. This is the kind of car that if you haven't done it, then it probably hasn't been done...

So I'm thinking that I'll probably replace the injectors with OEM or something similar.

IF a simple oil change made this much difference, I'd do another one in less than 500 miles... odds are good that LOTS of gunk is left in the system, and fresh oil will loosen it up for the next change.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

You might look into stretching the spring in the fuel pressure relief valve on the IP. Is tends to get shorter, which allows the fuel pressure to not get at high as it supposed to. When I did mine I felt a little more umph in my 78 240.

Here is a thread all about it
Fuel pressure relief valve adjustment

__________________