IDI Initial timing...non running engine.

[riotwarrior]

It occured to me that often folks are struggling with a first fire event or first refire etc.

This idea came to me today as I was speaking with a fella about a non running alledgedly good IDI. I explained it is something I could possibly assist with amd was invited to do so.

That being said I began to roll the roladex of issues...gp ....air i trusion...no fuel...weak lift pump....bad fuel filter...bad IP amd so on....but one thing u cannot check on a non running engine is timing.....but wait....could you???? No really coukd you????

This thread is for open discussion and I will personally test this theory asap.

My idea...dont glow my engine at all in am first fire.

Connect timing meter and set accordingly to std settings.

While cranking ....see if I can get an initial timing reading.

Now we know the IP is timed differently at idle vs 2 K and there is an advance and high idke fir cold starts so perfect....we have some baseline to whcih a person may be able to test and compare.


Like when @IDIoit had his issue if we coukd say check initial cold start timing at cranking speed it should be xx yy....then we would have a baseline to say wait...*** yer way out.

Well same holds true for anyone who cannot fire.....

Thinking outloud here guys....

Burned up the airwaves earlier as I called Gary @icanfixall about this.

Please guys....just lokking for feedback on a outside the box diagnostic brain fart....and no I had not been drinking when I thought this up...but am doing a few bevvies now.

Let me know yer thoughts and thanks for looking

 

[laserjock]

I think it's a neat idea Al. My knee jerk reaction would be I don't know how stable the reading would be cranking in short bursts to keep from toasting starter.

I'm pretty sure the meter averages to get RPM and probably the timing number too but I can't confirm that.

I guess if you are doing diagnostics you probably don't want it to try to start but you need the FSS active because otherwise you get no line pulse to read. So basically you would want to pull the glow plugs like a compression test.

That make sense?

 

[IDIoit]

I think this is a lot of work to catch a negative sign on a meter @ 2000 rpms

 

[riotwarrior]

The idea of pulling gp never occured tk me. Thats a great idea.

On my truck if I dont glow it wont go...so I could in theory just remove power to gp and then turn it over a few cranks to test theory....still like that no gp in idea.

 

[Dieselcrawler]

Really won't tell anything. After timing so many pumps, and seeing how far out they can be and still run, it is t worth the struggle

 

[mblaney]

I think what you should be concerned about is being 'near timed' vs 180 out... no? To me it should be easy... one flash from your timing light (while cranking) and if you see the reference mark that is close enough to run. Probably a bigger issue / concern is if you have enough pressure for your line clamp to work (assuming you are using a Ferret type clamp) at cranking speed - assuming that the lines have not been 100% purged, etc.

 

[Dieselcrawler]

They will, yes will run 180 degrees out....

 

[icanfixall]

The pump pressure is the same cranking or running. Whatever the injector pops at is the pressure the pump will show you.

 

[laserjock]

Agree Gary. Only thing that may change is timing to get to crack pressure depending on pump condition. If the pump is worn, it may make cracking pressure deeper in the stroke than normal. Don't know how much of an effect it might be though. Could be negligible.

I've spent some time thinking about this. It seems like most diesels are statically timed as is this one. Assuming it's put together right and the pump isn't hosed, you ought to be in the ballpark. About the only thing that could get you is if you are off some random amount on the pump gear. Off a tooth either way it will probably run albeit poorly. So it sounds like what is really needed is a simple way to check static timing without pulling the front or top cover.

Does that seem reasonable or is my thinking really off?

 

[Thewespaul]

What about the effect of different cranking speeds? Say we find xx and yy for Gary's application but Al's engine is worn out with no compression and he is cranking with one battery through a piece of extension cord... Would that difference in cranking rpm make a significant difference in timing or would it be marginal?

I think you guys are onto something here.

 

[FORDF250HDXLT]

im with Dieselcrawler.you might as well just set the ip straight up and start the truck.she'll start and run there (if not,you have other issues to resolve first) and then simply read your meter like normal.

i see what your thinking Al,and that is, the timing needs to be fairly close or else the engine wont run in the first place but these old gal's are just not that sensitive.