Diesel compression tester

[spock500]

As I work through the possible causes for non starting the most obvious one now is a compression test (see http://www.mercedesshop.com/shopforum/showthread.php?p=2127805#post2127805)

Does anyone have any advice on which brand? these SilverlIine ones look ok with plenty of adaptors

http://cgi.ebay.co.uk/ws/eBayISAPI....m=400013976850&ssPageName=STRK:MEWA:IT&ih=027

Thanks all,

 

[lynall]

I had a similiar kit sealey i think, worked okay on the couple of diesels i used it on, you can buy it, use it, sell it again on e bay and still be a lot cheaper than paying someone else to do it.

One diesel i used it on it went into the glowplug holes, other was so old it had the twin hold down bolts set up and again did the job.



Lynall

 

[Number_Cruncher]

I've just seen that all your injectors are spraying properly. I agree, a compression test is a good next step.

 

[spock500]

Ordering one today, thanks -

 

[Dieselman]

We've not seen your injector test, how did you get on.
I'm keen to see the compression results.

 

[spock500]

Morning DM,

Yup, posted a link above to;

http://www.mercedesshop.com/shopforum/showthread.php?t=234609&page=19

Video at bottom, if you would prefer can copy across to here.

 

[Dieselman]

Neat idea spraying the belt as long as you are prepared to write off the belt and possibly the pulley.
The belt won't stay in time with the engine, but the pulley will. No it won't as you've selected the water pump pulley, unfortunately this renders your test pointless.

The timing isn't 14ATDC, it's 15BTDC.
The 14ATDC is a nominal figure for static timing the pump using the pointer, which is offset.

 

[spock500]

Thanks DM for those words of encouragement

The test really was about the injectors to see if they were spraying, going to check the static timing again.

 

[Dieselman]

I initially thought you'd used the crank pulley, it was only re-watching the video that I saw it was the waterpump, which isn't timed.

FWIW I never thought the problem was fuel delivery, it's either timing or compression.

Just check again from the start.

You can time the pump by removing No1 injector from the HP pipe and turning the engine by hand until the open pipe spills fuel, then note the timing.

 

[Number_Cruncher]

>>FWIW I never thought

Maybe not, but, a simple and cheap test means that he now *knows* that the injectors are spraying. I'ts one thing that can be eliminated.

 

[spock500]

Thanks bud, shall I disconnect the number one pipe at the pump or at the injector?

 

[Dieselman]

Maybe not, but, a simple and cheap test means that he now *knows* that the injectors are spraying. I'ts one thing that can be eliminated.

I agree, and did originally suggest the test.

http://www.mbclub.co.uk/forums/showpost.php?p=698295&postcount=25

 

[Dieselman]

Thanks bud, shall I disconnect the number one pipe at the pump or at the injector?

Either end really.
At the injector will create a spill pipe so is easier to see, but at the pump will work, just dry out the delivery port and watch for it filling.

If you need my timing tool let me know, but I must have it back quickly.

 

[spock500]

Going through the basics to make sure I haven't done anything daft, will try spill method DM in a mo, thanks for the offer of the timing tool.

First of all cam positions at 14 degrees ATDC for static IP pump timing;

IP timing notch for static timing (14 degrees after TDC)

 

[Dieselman]

Should the cams be set at 14ATDC or at TDC.?
Your photo of the pump timing peg isn't quite straight with the oriface and the peg appears a bit advanced, though I would expect it to fire at that.

 

[spock500]

A better one of the notch with oil excess removed.

As I understood the manual you set the cams up at TDC on their compression stroke (lobes up ish) with crank pully, then you move the crank round to 14 degrees ATDC to set up the IP static timing or have I goofed up?

 

[Dieselman]

No. Your earlier post read as if you had set the cams at 14-ATDC as well.

That pump timing peg does look pretty close to central.

 

[spock500]

I have tried moving the chain around a tooth in either direction and you cannot see the notch at all.

Tried the spill method cranking with hand and no go, nothing appears in the small well recess after you remove injector pipe.

Cranked with starter motor and it squirts 2 feet in the air but my video camera is too slow to capture it

Thanks for all your help DM/NC, owe you a beer or two:bannana:

 

[Number_Cruncher]

***

 

[Dieselman]

Can we have a shot of the whole valvetrain with the engine at TDC. Those cams look well advanced and together for only 14 deg off TDC.

It looks like they will open both intake and exhaust simultaniously.