Injection pump from 78 into an 80? - PeachParts Mercedes-Benz Forum

wowwy · #1 06-12-2007, 01:07 AM

Will an IP from a 1978 300D fit a 1980 300SD? I don't know any other information about the 78, other than the guy I see tomorrow says I have to tell him then and there if I want the car or else he is calling the wrecker.

They guy says it will and the only difference is mine is turbo.

wowwy · #2 06-12-2007, 01:52 AM

Anyone?

slarson80 · #3 06-12-2007, 02:18 AM

I don't think so. IP's are finely tuned etc. I really doubt you can switch between turbo / non turbo. Don't know for a fact though. Are you trying to address the rough running issue? If so, IP is a very last resort. Try doing a search

Knightrider966 · #4 06-12-2007, 02:24 AM

Quote:

Originally Posted by wowwy

Will an IP from a 1978 300D fit a 1980 300SD? I don't know any other information about the 78, other than the guy I see tomorrow says I have to tell him then and there if I want the car or else he is calling the wrecker.

They guy says it will and the only difference is mine is turbo.

Thje turbo will make a difference but the IP should be the same. Injection rate is different because turbo's need a little more fuel than non turbo's but I know there is a way to adjust this, but it may require changing settings and CO. I'm not sure how to do this, but I've had it done. if the pump is cheap enough go for it.

vstech · #5 06-12-2007, 08:35 AM

no.
there is not any way for a non turbo IP to enrich the fuel for the turbo. it may work, but you will have dismal power.

barry123400 · #6 06-12-2007, 09:07 AM

There is no fuel enrichment device as the boost comes up. In otherwords you will have increasing air volume and no corresponding amount of fuel for it. If you have isolated a problem to the injector pump let us know how. There are ways to do this.
Also I much preffer to remove a used pump from a donar engine still full of oil. Sitting around off the engine without proper storage can introduce problems to a pump.

wowwy · #7 06-12-2007, 10:46 AM

ok, thanks guys. I still can't get the car to even start. I have checked everything with no luck. the only thing I have to check is the compression which I am doing tomorrow when I get the guage. So far I have traced all the problems back to the IP, thats the only thing I can think of. I did notice on the pump that the last output, closest to the firewall has no output when all the lines were off, and when I removed all the injectors 3 out of 5 were dry, with absolutly no signs they have even fired?

I can get a working IP (actually the whole car) for $100 but it's not from a turbo.

Other than the lack of power, will I do any damage to the engine?

This is so frustrating!!!

barry123400 · #8 06-12-2007, 11:23 AM

Was car sitting around a long time unused? You would not have three elements not pumping unless they were the last three and the crank was broken in the pump. You could have the pump pistons stuck at the top of their bores though from sitting around too long. Also before jumping there I would rig a can of fuel a foot or two higher than the injection pump and try gravity feeding it to make sure you are getting fuel in there. Leaving even one line off an apparent non producing element like number five in the pump will soon answer your question.
If it turns out you really have a bad pump and you are not there yet. The 100.00 applied toward the proper turbo pump replacement would be better . I can not see you being happy with the natural aspired pump in my opinion on this engine.

wowwy · #9 06-12-2007, 11:30 AM

the one I am trying to get started? yes, since 2001.

The previous owner said he was driving it, it kept loosing power, started to smoke one day, then there was a bang, and it hasn't run since.

The amount of times I have cranked this thing over I should have new fuel in it by now.

I have the fuel line stuck in a gerry can, sitting on top of the fuse panel block. The only one that has no output is the last one, all the others seem to fire about the same.

Is there anyway to "free' that valve if it is sticking?

Knightrider966 · #10 06-12-2007, 01:24 PM

Changing the delivery valves was one of the things I had done to my pump! Now I took mine off and took it to a specialist but they told me they were esentially the same,but the turbo model had a boost feature that added more fuel and higher boost pressures.

wowwy · #11 06-12-2007, 02:00 PM

ok, just got back from looking at that other 300D, and this is what I found:

Mine: 1980 300SD
617.950 engine
116.120 chassis
(I can't read the IP number)

His: (door plate says 76, everything else says 78) 300D (non-turbo)
617.912 engine
123.130 chassis
IP numbers: 350/2200 MW19
PES 5 MW 55/320 RS 15

The shop manual says that in 1980 there was no such thing as a 116 body design?

My main question is......Can I put that IP pump from his onto mine without any engine damage? With there being a turbo, will it lean out or just generate less horsepower?

Then I can determine how strong of a runner this car really is.

winmutt · #12 06-12-2007, 03:01 PM

There is no such thing as to lean etc in diesel world. You can put the IP on but you will always run lean. You might be able to fiddle with max fuel etc settings but you really want the proper IP regulator for the right engine.

barry123400 · #13 06-12-2007, 03:46 PM

Rather than actual lean the condition is better described as inadaquate fuel available. I surmise this from the ideal that after a burn cycle in a diesel there is usually some oxygen left over. This may be wrong though. Especially when they are so overfuelled that they blow black unburnt or poorly burnt fuel smoke.
No actual harm will come from running the n/a pump but I do not think you will be happy. It will bolt up and time the same.
I think the bang thing is still your real issue. You might need the n/a engine and it's pump as well.
If you have access to an air compressor you could inject air into each cylinder with it's valves closed and see if air is rushing out of any given cylinder.

wowwy · #14 06-12-2007, 04:41 PM

how would i get the air into the cylinder? I don't have an adaptor that would fit, besides, isnt that just the reverse way of testing the compression with a compression testor?

After spending hours on the phone I may have found an IP out of B.C. for $400 and with a 30 day warranty, and this is off a turbo car. so thats good

Basicly I am waiting for tomorrow to see what the compression test results bring.

I'm kinda hoping that the bang he said was mabey a backfire or something not serious? But I still have to keep the fact in the back of my mind that when I turned the engine over with the oil cap unlocked and sitting on the valve cover it kept wanting to blow the cap off, and did so twice, So it really is up to what the compression test reveils.

I know there is not supposed to be alot of blow-by when running, but what about when starting/cranking the engine over? Would a whole in the piston cause that blow-by or would it be a valve, or is it even normal for that much blow-by when cranking?

wowwy · #15 06-13-2007, 03:27 PM

Ok, here are the results of my compression test:

Cylinder #1 220
2 215
3 215
4 220
5 170 (230 after oil put into cylinder)

The Piston must have been stuck on the 5th output of the IP but isn't stuck now, they are all shooting the same.

When I took the injectors out, there was no heat shield installed in the first cylinder, the rest were there. All the injectors were bench tested with a spray around 200PSI with a good spray pattern except for the one out of the second cylinder which had no spray until it hit 340PSI, then it just shot out in a very pronounced line.

What do you guys think?