Sometimes I run and Sometimes I don't.....

ndnjames13 · Sep 8, 2019

Got a 97 7.3 260000 miles

Sometimes when I start her up sounds like i dropped three injectors and and I got a HUGE cam. I can drive it and sometimes feels like the misses go away and come back and i get a lack in power. No codes that I know of and not sure where to start..

SebastIDIan · Sep 8, 2019

Is it a whole bank going out intermittently or random cylinders?

Could be a couple different things or a combination of them.

CPS is a good start, also check the wires going to it and also the wires going into the cylinder heads for chaffing, melted or cut wiring.

Shake your idm to see if its got water in it.

Someone more knowledgeable will chime in but this is what I dealt with with mine.

ndnjames13 · Sep 8, 2019

I have not seen anything weird out of the tach. I don't really know if its a bank or random cylinders. However I do know that it runs right randomly so I'm not thinking compression. Sometimes at idle I notice A LOT of white smoke.

greenskeeper · Sep 8, 2019

probably a burnt UVCH. Remove the oil cap and give a sniff....do you smell burnt plastic/wiring ?

If the failure is intermittent, the PCM will sometimes shut down 1 bank of cylinders giving you that "big cam" sound as the engine tries to run on 4 cylinders.

Another test with the engine running in "big cam" mode (lol) :

disconnect one harness at a time going to the UVCH....if the engine idles the same then you've found the bad harness. If the engine dies then you've disconnected the working harness.

If you do replace the harness, go with motorcraft or international only and nothing else !

ndnjames13 · Sep 8, 2019

Is there a way that I can check them with a multi meter?

greenskeeper · Sep 8, 2019

ndnjames13 said:
Is there a way that I can check them with a multi meter?

they can pass the meter test and still be bad. Easiest to do the oil cap sniff or harness test while running. Heck if it was my truck I'd already have the valve covers off as it's not that hard to do.

ndnjames13 · Sep 8, 2019

Ok, Ill do that. I just prefer diag stuff with more of a definite reason. The more I look around though the more that sounds like the issue I'm having. I've read that i should see oil coming from the injector while running?

lotzagoodstuff · Sep 8, 2019

One quick and dirty method for figuring out what bank is getting turned off is with a cheap infrared temp gun on the exhaust manifold when it's cold started. If you figure out what side it's on, that will help you. I can tell you that if it's the driver's side, it's pretty easy to remove that valve cover and take a look at the UVCH. With that many miles, it's pretty common to see one completely melted, which could make your diagnosis pretty easy.

Good luck, I spent some time chasing down OBS 7.3 gremlins and all I can say is that pulling codes and looking at live data with something like Forscan will help, but check out the notorious/obvious stuff first.

Good luck!

greenskeeper · Sep 9, 2019

ndnjames13 said:
I've read that i should see oil coming from the injector while running?

Correct. Oil should come from all 8 injectors while running or cranking the engine over. This indicates that the injector is firing on the oil and electrical side. The only thing left after that is fuel (aside from a mechanical failure of an engine component.)

ndnjames13 · Sep 11, 2019

Ok, update time. I found a connector half hanging out of the female end. The gaskets are like new Someone before me did them. I did a voltage drop test and all voltages were equal. Truck ran amazing for about a day until now. WHITE SMOKE everywhere. Feels like a misfire for sure on one cylinder. When the miss is really bad no white smoke at all when I get the injector back it pours white smoke. I'm 90 percent sure I need a new injector. I did change the oil and add hotshots but I think it wont help. I will get a hold of a snap on solus scanner and do a contribution and buzz test. Is the any other way to make that test happen?

lotzagoodstuff · Sep 12, 2019

Solus scanner is very nice, but if you want to go a cheaper route you could get yourself a wireless dongle and use Forscan software. Do a search on Forscan, it's pretty useful and you can't beat the price.

ndnjames13 · Sep 14, 2019

Is this the dongle you are referring to

https://www.amazon.com/Forscan-Scan...ocphy=9006113&hvtargid=pla-637551798938&psc=1

If so I'll buy it if not what do you recommend.

79jasper · Sep 14, 2019

That one will work to hook to a laptop. I would get that one, plus one to use with your phone. Bluetooth if you have android, wifi if you have iphone.
(They are more expensive, but I prefer the obdlink brand dongles)

Sent from my SM-N960U using Tapatalk

ndnjames13 · Sep 14, 2019

Ok, I found this oblink one with bluetooth

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/p/626198486

79jasper · Sep 14, 2019

That's a clone.
http://www.obdlink.com/
They can be bought on Amazon. I have the older mx, will upgrade to the mx+ eventually.
But I use mine on other vehicles, so i can justify the price.

Sent from my SM-N960U using Tapatalk

Sometimes I run and Sometimes I don't.....

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