Woo-hoo, It's Alive!!!! - PeachParts Mercedes-Benz Forum

wowwy · #1 06-21-2007, 12:53 AM

Ok everyone who has been following the sega on my 300SD re:78 injector pump into in 80?

I got the car running today, took alot of cranking and a new starter (no there is no fusable links associated to the starting system) but it does run now.

Now heres the newest problem:

when at idle the oil preasure is showing #1 on the guage, and it goes up too #3 when revving. There is a loud um......banging.....clanging......almost like a rod knock, but I don't think it's that. At idle it's very pronounced and gets worse the more you rev it up, with a maximum redline of about 4000 rpm. When you take the aircleaner off it gets really loud, almost like there is a crazy guy inside the engine hitting the block with a hammer. When you put it in gear there is no power, but i can hear the turbo spool up, sounds like it's really trying to work, even when in park. After you hold the throttle to the floor for a couple of seconds, you can't let it off too fast as the engine will stall.

All the fuel filters have been changed, including the strainer in the tank, and it has fresh fuel in the tank.

I think I am getting closer but not sure which way to turn now?

rs899 · #2 06-21-2007, 07:21 AM

Owww. You can try loosening the injector feed lines on top of the injectors one at a time and see if the noise changes. Sounds like it may be expensive.

vstech · #3 06-21-2007, 07:57 AM

the no power part of the story, leads me to believe you have indeed got a bad rod. or crank bearing failure... hmmm.

MB-Owner-in-ind · #4 06-21-2007, 12:04 PM

I am wondering if the injection pump is capable of delivering enough fuel. I haven't been following this saga but I thought I read that a NA pump doesn't work in a turbo without mods.

vstech · #5 06-21-2007, 12:09 PM

now that I think about it, the N/A injectors have a lower pop pressure, and a lower volume of flow too... that could cause a properly timed IP to fire late, causing very poor power... perhaps if you changed all the injectors to match the IP, you would have better luck with the motor.

wowwy · #6 06-21-2007, 01:01 PM

opps, sorry guys, forgot to mention that I did get the fifth output of the IP to start to fire so i left it in the vehicle and alone. thats the only thing i havnt checked is the IP timming. If it was off, would that cause that noise i was hearing? I had a bearing let go in a SBC and it didnt loose any power like this thing is loosing, when i am in drive and pin it, I can barely get out of my own way!!!

I am going to take a video of it today and will post it on youtube and give you guys an address to go too, hopefully that will be easier to diagnose?

Thanks all

arew264 · #7 06-21-2007, 01:56 PM

Glad to hear you got it running.
Just to clarify, you managed to keep the turbo IP, so you have the right IP for your engine, right?
Have you checked your IP?

I'm with the poster that said to crack each injector while the car is running and see if the sound changes. That would indicate a problem injector or cylinder.

DrewGerhan · #8 06-21-2007, 02:41 PM

Quote:

Originally Posted by wowwy

When you take the aircleaner off it gets really loud, almost like there is a crazy guy inside the engine hitting the block with a hammer.

Well this is an easily solved problem... take the guy's hammer away.

TheDon · #9 06-21-2007, 02:51 PM

time the IP and put the correct injectors and see what happens

wowwy · #10 06-21-2007, 02:52 PM

Yup, have the factory IP still on the car.

Going out right now to crack each line to see if that makes a difference.

As for the guy with the hammer, does anyone know what he's like to deal with? Is he going to put up a fight or go willingly?

BioPOWER · #11 06-21-2007, 03:35 PM

You'll have to find him first. Then you can see about taking his hammer away!

DrewGerhan · #12 06-21-2007, 03:47 PM

Exactly.

wowwy · #13 06-21-2007, 05:30 PM

Ok, first off, I found that dude with the hammer!!! I took away the hamer then promptly beat him with it!!!

bad news #1: The car still knocks when it runs.
bad news #2: The guy I beat with his own hammer, was my neighbour!!

Ok, tried loosening off each injector line, every one that I loosened caused the engine to loose some RPM and run rough, so I couldn't pin point the problem to just one cylinder.

Just out of curiosity, how would these engines run if the timing was out on the IP? I know the timming is spot-on with the crank/cam, but I need to know if the IP timing would cause this situation before I takle that due to my broken hand making it really hard to do things.

Oh, the most i can get the revs to is 2,700rpm before it won't go any higher.

Thanks guys, oh, if the cops ask about some guy getting beat with a hammer, I DIDN'T DO IT

psfred · #14 06-21-2007, 10:42 PM

If the injection timing isn't very close to what it should be, you will get horrible knocking (if too fast), low power, and lots of smoke at either high or low speed.

Worse, it WILL run 180 degrees out (fuel injected at the end of the exhaust stroke, I think), but will run very badly, knock like crazy, and refuse to develop power.

There are some IPs that have the mark on the driveshaft 180 degrees out, don't know which ones, but it's a known problem.

To set timing, you need either a factory drip tube or a substitute (rubber hose will work if you cut the end at a slant). Remove the #1 injector line, take the pressure valve holder off the IP, remove the spring and small steel valve (don't lose them!), reinstall the pressure valve holder, and install the drip tube, or your rubber hose. Bend the hose around so that the sharp point is on the bottom and pointed down.

While maintaining pressure in the IP with the hand pump, slowly rotate the engine toward 26 degrees BTDC on the compression stroke for #1 cylinder. When the fuel flow out the drip tube drops off sharply, the plunger has covered the fill slot in the sleeve (inside the pump), and the crank should be at exactly 26 degrees BTDC. Loosen IP to adjust. Loosen the three nuts holding the IP in place and rotate it toward the block to make the injection earlier or away from the block for later. Rotate engine two turns and verify correct timing, then tighten the nuts all the way, replace the valve and spring under the pressure valve holder, and re-start.

Make absolutely positive that the crank/cam timing is correct -- if you are off one tooth on the cam gear, the exhaust valve will hit the piston on each cylinder, making a terrible racket and resulting in very low power. It will also dent the pistons and eventually snap the cam towers. check by rotating the engine by hand -- any hard spots with clunks means something it hitting.

Peter

wowwy · #15 06-22-2007, 01:02 AM

Ok, will hopefully try this weekend to do all that. The one thing I'm not sure about is the marks on the crank for the timmming marks. When I checked the cam against the crank there was a pin on the crank pully with numbers on both sides of it, but i couldn't read the numbers very well. memory serves me correctly the pin was around the 4 degree mark, is this true?

I have done several serches to find out what the crank pully marks would look like but have had no luck so now I'm not 100% sure if I did read the timming marks right?

That drip tube, does it have to be a certain angle and length?, or just as long as its at a right angle so the drip will fall down the pointed side? Ive seen pictures of them before but it didnt give any measurments.

Thanks again for all the help you guys have been giving me