Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: sens on June 12, 2025, 20:13:16

Title: Easy FIP timing test
Post by: sens on June 12, 2025, 20:13:16

Hello,

To check whether your FIP is installed correctly or 180 wrong, there might be a test you can do without removing the FIP or a check valve on the FIP.

In a 4 stroke engine fuel is injected in the beginning of the first stroke (assumption 1).
Ignition is at the end of the second or in the beginning of the third stroke.
So half way the total cycle.

The moment of ignition and injection should alternate like a ticking clock.
If the FIP timing is 180 dgr off, ignition and injection would be at the same moment. (assumption 2)
The engine will run, but rich and with less power.

I disconnected the fuel line of injector 6 and mounted a spare injector.
The stroboscope on cil 6 showed me the spark flash of that cilinder.

Looking at the video I took with my iPhone on slow motion, you can see the timing of the spark and of the injection.

My conclusion is that based on this video I think the timing of the FIP is correct.


Would you agree??
Any comments??

Thanks! Halvor

Title: Re: Easy FIP timing test
Post by: sens on June 18, 2025, 14:52:32

Any comments?

Have a good day!

Halvor

Title: Re: Easy FIP timing test
Post by: clunker on June 20, 2025, 14:47:46

This looks like a clever way to confirm the phase of FIP timing - creative use of strobe and phone camera! I think it is a small set of folks who are currently rebuilding an FIP, but I’d expect at sometime someone will find this and go ‘aha!’

Title: Re: Easy FIP timing test
Post by: sens on June 20, 2025, 14:59:11

Thanks Clunker!

In Quick Time Player you can ever count the number of frames between the events and calculate the time between them

I found in my case:

injection             Spark          Injection

    <---  43%  --->    <---  57%  --->

     < ------------- 100% ------------->

Have a good day!

Halvor

Title: Re: Easy FIP timing test
Post by: Benz Dr. on June 20, 2025, 18:44:11

When I start to rebuild an engine I always turn it to TDC number one piston. Before I remove the IP I continue to turn the engine to 20 ATDC to check IP timing. Knowing that both the cam and IP are in time with the crankshaft before you start disassembling can give you good info on your rebuild. At 20 degrees ATDC the marks on your IP should line up.

Title: Re: Easy FIP timing test
Post by: sens on June 20, 2025, 20:57:21

I fully agree with you Dr. Benz.
This is exactly the way I did it.

However I read somewhere that a common mistake is 180 dgr. off timing of your FIP.

If you are not sure and you want to eliminate a mistake, this is a simple way to find out…

Title: Re: Easy FIP timing test
Post by: ja17 on July 11, 2025, 04:10:13

I have a method to check if the timing is 180 degrees off without removing the pump. It is not for fine adjustment of the timing but will save you from removing the IP if you are not sure. Remove the injection line on #4 cylinder of the injection pump (3rd from the back). The piston (plunger) #4 cylinder in this injection pump should be at top of it's stroke at 12 degrees after TDC of the engine cylinder #1 (compression stroke, both camshaft lobes upward). If the engine IP is timed 180 degrees off the #3 IP piston (plunger) will be down. This method will only tell you if the timing is grossly off of spec, like 180 off.

Title: Re: Easy FIP timing test
Post by: sens on July 11, 2025, 07:21:24

Thanks for your reply Joe!!
I am sure that will work.

What do you think of the procedure I described?

Have a good day!

Halvor

Title: Re: Easy FIP timing test
Post by: Pawel66 on July 11, 2025, 11:57:41

I could swear I took it from Technical Manual, but maybe it was from some post. Anyway, this is what I used.

Title: Re: Easy FIP timing test
Post by: sens on July 11, 2025, 14:04:05

Yes,

I have seen that.
However I think the method I used is far easier.

Hook up a stroboscope and disconnect an injector. That's it.

All the best.

Halvor

Title: Re: Easy FIP timing test
Post by: ja17 on July 12, 2025, 05:11:33

Very impressive procedure Halvor! Yes I think it should work!

Title: Re: Easy FIP timing test
Post by: sens on July 12, 2025, 09:50:29

Thanks Joe!

Have a good day!

Halvor