Cylinder Contribution test

[tjm]

This can only be the injector right? Either the tip or the solenoid.

 

[AH64ID]

What are the specs on the injector? Stock? Miles?

 

[tjm]

Hey John - Stock, 100.3K

Did stock fuel filter for 90k miles

 

[BigPapa]

Have the injectors been out recently? Any other fuel system work lately?

 

[tjm]

Have the injectors been out recently? Any other fuel system work lately?

Never been touched Scott. No other fuel system work other than the remote fuel filter about 10K ago

 

[Ozymandias]

Does it show same numbers every time you run the test?
I never relied on this test solely, for me the numbers aren't disturbing.

 

[AH64ID]

Hey John - Stock, 100.3K

Did stock fuel filter for 90k miles

How does it drive? How’s the fuel economy? Any other symptoms?

 

[tjm]

How does it drive? How’s the fuel economy? Any other symptoms?

Ha vent noticed a loss in power. Fuel economy - nothing noticeable.

 

[tjm]

Does it show same numbers every time you run the test?
I never relied on this test solely, for me the numbers aren't disturbing.

ran it once. I'll run it again.

 

[Ozymandias]

ran it once. I'll run it again.

Do that, as I've never seen the same numbers again at a second or third test run.
Like said, your numbers don’t disturb me at the first sight, I've seen similar with mine.
And I've never seen 6x 100 - they have been off always.

I don't want to disturb you, but the contribution test can also show mechanical issues with the rotating assembly as it compensates for anything that gives an imbalance to the torque stream, compression for example.

 

[tjm]

Yep its different - all of them. Ill run another test later at high rpms

 

[sag2]

Easy way to tell is swap #3 injector with another (do the easiest one to remove) and see if it follows the injector.

 

[tjm]

Easy way to tell is swap #3 injector with another (do the easiest one to remove) and see if it follows the injector.

That is true sag2. If I'm going to swap 2 injectors I might as well replace all of them. Would like to have this truck run for 7 more years. Only has 100k on it. Mostly stock. Stellantis is stating no more combustion vehicles post 2030.

 

[BigPapa]

If I'm going to swap 2 injectors I might as well replace all of them.

You misunderstand. He’s saying put #3 where #4 was and #4 where #3 was, not REPLACE them with new ones.

 

[AH64ID]

I would take the time to swap and confirm first.

If it follows and you have no other indications of an injector issue I don’t think you need to spend the money right now.

 

[sag2]

If you just stuff a set of injectors in it and you end up with the same problem you will have just wasted $3k. The swap is easy.

 

[tjm]

Yeah I get what swap means. Maybe I can do that as a practice run for learning how to replace injectors. Been wanting a little more oof.

One question. Do the tubes follow the injector?

 

[Ozymandias]

No