7.3 issues? still smoking....

rockcentral4wd · Sep 19, 2012

I bought a truck... it was idling rough and not running great... he put injectors in it last year and an IDM the day i bought it. Took it and had it scanned, it came up with a cylinder 5 misfire code. while idling it will smoke and smells strongly like fuel out the exhaust. if i unplug injector 5 it quits smoking.

replaced number 5 injector... idles smoother but still smokes... if i unplug cyl 5 it will get better. when i drive the truck sometimes it will plume lots of smoke and sometimes it picks on up like it wants to go but still hesitates slightly...

im kinda stumped and any help or direction would be greatly appreciated!!!

its a early 99 with 158k miles...

TrailerHauler · Sep 19, 2012

Has a compression test been done?

rockcentral4wd · Sep 19, 2012

No I haven't done a compression test yet because I couldn't see how that would cause the over fueling smell and since when I installed the new injector it solved the rough idling issue but I could be wrong.

Arisley · Sep 19, 2012

I would do a compression test, pull the injectors and send them off to be tested.

silverpsd_06 · Sep 19, 2012

Maybe a bad harness? Swap holes and see if it follows the injector..

TrailerHauler · Sep 19, 2012

I would do :whs: and a compression test.

You said the smoke went away when you unplugged the injector, and the smoke smells strongly of fuel... That injector may be firing and working properly, but the cylinder may not be burning off all the fuel. That's why I suggest a compression test, low compression won't burn all the fuel.

TARM · Sep 20, 2012

Already replaced the injector and it stayed with the hole. SO injector is not the issue. But if the old injector was dumping tons of fuel............I am with these two compression test that hole.

If you have a hole in your piston or some other reason for no compression that fuel is not exactly combusting but instead the raw fuel could be dumping out the tail pipe.

silverpsd_06 · Sep 20, 2012

And replacing an injector doesn't necessarily rule out a faulty harness. Either way I would do a compression first before you go throwing a new harness at it. If it comes out ok then I'd start pointing my finger at the harness

rockcentral4wd · Sep 20, 2012

Sweet Preciate the info. I'll see about doing a compression test and go from there.

rockcentral4wd · Sep 20, 2012

What psi is considered to be bad compression on this motor?

stroker2 · Sep 20, 2012

rockcentral4wd said:
What psi is considered to be bad compression on this motor?

Depends on the altitude your doing the test at. I tested mine at almost 7k feet and averaged 330-340psi. They should be right around 400psi at sea level i believe

rc4wd · Sep 20, 2012

The truck is in Tampa, Fl so yea it'll be tested around sea level.

rockcentral4wd · Sep 20, 2012

Ski guess you would consider 200 psi with oil in the cylinder to be good right?(sarcasm for those who may have missed it. Lol). It only tested 100 the first couple times. I almost feel like I wasn't getting an accurate reading. I don't feel like my adapter was sealing properly.
Going to see if I can find another tester and try again but I think I'm still ultimately going to get the same result! FML

stroker2 · Sep 20, 2012

Crank it over a few times to get the peak psi and operating temp is best because the piston rings seal better (what i have been told)

TARM · Sep 21, 2012

spray some soap water around the insert and that will tell you if you have a good seal. Did you test more than one cylinder?

rockcentral4wd · Sep 21, 2012

I cranked it over several 5-6 times and it only got just above 100 then back the adapter out added some oil and got over 200! My adapter would start in the hole and then stop about 5-6 turns in and get tight. It didn't want to thread all the way in and I didn't want to make it in fear of cross threading but it appears that I may have done it anyways! FML. So I stopped and will reevaluate again since it got dark on me. Thanks for the input guys.

stroker2 · Sep 21, 2012

Doubling that pressure just with oil im pretty sure means you have a slight leak either past the rings or valve seats or possibly through your adapter if it was cross threaded.

TARM · Sep 22, 2012

Yep could be anything. You need to get a good seal as you know on that adapter. Maybe the adapter threads are damaged up at the point where it started to get hard to thread. Look at it and if so you can run a nut or better yet a die to fix those threads.

rockcentral4wd · Sep 22, 2012

The glow plug will thread all the way in but I am losing pressure around the adapter. I even tried putting some Teflon tape on it to make it seal but didn't work. I tested the cylinder 3 and it seats and threads fine into it. Who knows. I tested it last night motor cold with about the same results but I did notice that my overflow bottle released pressure when I took the cap off. I didn't think that it should have pressure since I haven't run the truck since Thursday but correct me If I'm wrong?