Made a total and complete mechanical fool of myself

[MikeP]

And wasted $700+ dollars on top of it doing precisely what I always claim to NEVER do...P1$$ poor troubleshooting!

I've posted a couple recent threads about a problem with my 16KW NL Genny. I won't go into the description of the issue, it's in other threads.

After initially troubleshooting, with the help of an NL tech, that it was the generator part of the system loading down the engine, it turned out not to be the problem. Then I did an injector "short" test and discovered that cracking the injector on #4 made no apparent difference in the engine's running. So...injetor problem, right? Four new injectors later I started the engine and...no difference - very low RPM running/huge quantities of black smoke.

Turns out Dr Jim fixed it...sort of. Read on.

Earlier in the troubleshooting I had removed the intake manifold because, in checking the filter, I discovered there wasn't one! So I though it might have collapsed and pulled into the manifold, blocking the air. but I didn't see any sign of that. So I reinstalled the manifold with just a couple of screws, rather loosely and started the engine again, this time with the generator section of the Genny turned off so it was not loading the engine. Engine started and ran perfectly. I figured, AHA, it was the generator section as per the NL guy. I turned the Gen section on and it continued to run correctly so I figured that the regulator had "reset itself"...also as the NL tech said it might.

Then later, after bolting everything back up and with the Gen section turned back off, the engine once again would not run properly so I did the injector test and found the "bad" injector. In the back of my mind I kept thinking that wasn't really the problem but I didn't put the mental pieces together...

Jim and I were talking the other day and I mentioned what I had done and he said, "it ran OK when the manifold wasn't tightened down but didn't when it was?" I replied that that had nothing to do with anything, But I was wrong.

This eve, after installing the new injectors and finding the engine wouldn't run properly, I loosened the bolts on the intake manifold figuring...what the heck. Engine ran perfectly!

Turns out that the air filter HAD collapsed and clogged the intake manifold but it had moved all the way down to the end of the manifold to a 180 degree turn where it could not be seen at all. I had to run a coat hanger down the manifold and felt it hit something spongy. The reason the #4 injector didn't make any difference in the engine running was probably because it was at the far end of the manifold and couldn't pull in enough air to make much difference.

So the problem was NOT anything wrong with the Gen section OR any faulty injectors...it was a collapsed 5 dollar foam air filter. Oh well...I now have a set of spare injectors but I'm not happy about it. I absolutely despise poor troubleshooting and "throwing" parts at a problem and that's exactly what I did!

Here's a couple of pics:

They are in reverse order. The first shows the filter which was jammed at the 180 point of the manifold this pic was taken after I managed to work some of it out where you could actually see it. Before that, there was no visual way to see the jammed filter. I had reached down the manifold with a long screwdriver but it wasn't long enough to reach the very end but I figured it would have just stuck in the first part of the manifold somewhere...BAD TROUBLESHOOTING!

The second pic shows the manifold from the underside. The filter is a square foam jobby that sits in the rectangular end of the manifold and is then enclosed by a cover plate. It was totally jammed in about 2 linear inches at the 180 curve in the manifold.

[rsmith]

Could be worse, you could be still scratching your head and wondering what's wrong

[SeaEric]

The good news is: you figured it out! This process sure beats the crap out of paying a tech his hourly wage to throw parts at it and then NOT figuring it out. Bravo.

[bobk]

So why did the filter get sucked in, and how do you prevent another occurrence?

BTW, inform the NL tech so others do not have to suffer the same problem.

Bobk

[Seabrooke]

I'm sure, Mike, that we've all made errors on that style.

I'm also quietly tipping that if your tech had changed the injectors and then found the collapsed filter you would not have heard of it.

The main thing is, your genny is back up and working.

[JLR]

Mike - we all make mistakes. Heck, when I bought my 74, the survey showed that both the AP head and the Northstar on the bridge were not working. Rather than try to troubleshoot the problem from 1,200 miles away, I bought a new head and a new Northstar. Well, it sure is nice to have the new units but the installer in Florida to whom I supplied the new units advised on installation that that there was no problem with the old units. An inline fuse was blown. Close to 3K spent and not needed. I am certainly not as talented as you are or most other members on the forum. But, I really enjoy tinkering. I have two mantras when doing so. If something appears broken, it needed repair even if I made it worse trying to repair it. Also, if I get something to work when it wasn't working before AND, I do not know why it is now working, it has NOT been fixed and will likely fail at an I opportune time in the future. With all of that said, I hope to joy of fixing it outweighed the cost of a set of spare injectors.

[davidwigler]

Mike, treat yourself like a friend. Give yourself a break.

[jim rosenthal]

Mike, there are only two kinds of people: those of us who've made identical mistakes, and those of us who have done it but won't admit it. Stop beating yourself up.

You might also think about the fact that other people are NOT going to do this, based on what you've posted here. We will, however, find OTHER mistakes to make....

[rwappleton]

Mike,

Thanks for making me feel normal! Keep up the good work. I would almost bet it would have taken a tech three removals to find it.

Russ Appleton

[GJH]

Mike, the thing I love about you is your total transparency. But really, please, making a total (mechanical, boat handling, you name it) fool of oneself is my franchise, not to be challenged. Please respect that, Thanks!