PeachParts Mercedes-Benz Forum - Harbor Freight compression tester: injector or glow plug hole?

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- - Harbor Freight compression tester: injector or glow plug hole? (http://www.peachparts.com/shopforum/diesel-discussion/193228-harbor-freight-compression-tester-injector-glow-plug-hole.html)

I am sure the FSM says to WIRE the manual fuel cutoff switch to the OFF position before doing this...
I am heartened to see that some of those adapters for either hole look like they do not change the total volume much...
Relative compression ratio between the cylinders is also very important ... which this would provide given the same part would be used on each cylinder.

Thanks Number Cruncher. Elementary math seems to have eluded me there for a minute.

I just used my HF compression tester yesterday with the injector adapter, very easy to use! I have one dead cylinder (or almost) and another very sick one. 400, 420, 320, 380, and 160:grim:. Another forum member said to use Marval Mystery Oil and soak the low and dead cylinders which I am doing. On Friday will check the value adjustment and flush out with fresh old. Then recheck the low and dead cylinders with new heat shields and see if there was any improvement. Then pull the GP and check the compression that way to see what the differences are and report them here.

ForcedInduction :ban:recommended the Italian Tune-Up and also an aluminum safe carbon cleaner for guns and soak the sick cylinders. Then flush with a fresh oil change... might do that in a few weeks if the Marval Mystery stuff doesn't work.

Quote:

Originally Posted by Scott98 (Post 1555746)

I must have pulled the injectors on my 240D 3 or 4 times since I've had it through all the work I've done to get it running right. I always reused the old heat shields. I know its not the proper way but its not like you are going to have some catastrophic results if you don't. If I was rebuilding my injectors, then yes I would replace the heat shields. If I had to pop one out real quick for something else then no I wouldn't. I'm sure many here will disagree but I thought I would add my experience with them.

Scott

The heat shield protects the injector nozzel = failure to replace them leads to heat damage.

Injector, injector Heat shield, injector Nozzle and Prechamber + Collar LINK THREAD
http://www.peachparts.com/shopforum/diesel-discussion/211750-injector-heat-shield-nozzle-prechamber-collar-nailing-link-thread.html

Have a great day.

>> Elementary math seems to have eluded me there for a minute.

Actually, it had eluded me.

The swept volume S remains unchanged - so, 600 remains 600, not 607.

D'oh!

So,

CR = (S / (C+v))+1

I'm kicking myself!

For greater absolute accuracy, one could fill the hollow snout of the injector-hole test adapter with something like JB Weld, leaving a small passage, say one-eighth of an inch, through the middle. I have a Harbor Fright tester that worked fine on my '80 300 TD 617.
Steve

Quote:

Originally Posted by GWNorris3rd (Post 2268023)

I am one of the members who used the Marvel Mystery Oil (had hazy smoke at idle and some at speed) on what I believed were sticky Rings caused by the car sitting about 1 year and not runnig and driving 6 months with what turned out to be a Thermostat opening too soon an running the Engine colder than it should have been.
In my case the Marvel Mystery Oil worked.
But I had to drive the Car afterwards to free them up. I recommended it as it is available and inexpensive.

I took a look at my Harbor Freight Injector adapter and it indeed has a big hole down the length of it and this indeed makes it unusable the way it is.
Besides having a smaller hole in them all of the glow plug adapters have Schrader Valves in the tips.
If I ever decide to use the Injector adapter I will have to fill the hole with a Epoxyed rod that is drilled through with a small hole through the length.