7.3 intermitent engine shake

lincolnlocker · Jun 28, 2015

02BigD said:
Afternoon mini project?

It amazes me, years go by, different forums, and it's still heck to get some people to hook the dang truck to a scanner...just throw parts at em. Figure it out sooner or later...

yuppers!

live life full throttle

JD3020 · Jun 28, 2015

Especially with how cheap scanners are now days, hell you can turn your smartphone into a scanner for $30. 0 reason to not own a scantool of some sorts.

lincolnlocker · Jun 28, 2015

JD3020 said:
Especially with how cheap scanners are now days, hell you can turn your smartphone into a scanner for $30. 0 reason to not own a scantool of some sorts.

only thing is with the smartphone that i found with the torque app is that you have to have a higher end obd adapter.. which i think is 80 to 90 bucks for a good one cuz the cheap one i have wont link up to my 7.3s. but works just fine on my 6.7... but still the adapter and a 5 dollar app is well well worth it!!!

live life full throttle

ja_cain · Jun 28, 2015

lincolnlocker said:
only thing is with the smartphone that i found with the torque app is that you have to have a higher end obd adapter.. which i think is 80 to 90 bucks for a good one cuz the cheap one i have wont link up to my 7.3s. but works just fine on my 6.7... but still the adapter and a 5 dollar app is well well worth it!!!

live life full throttle

I can do cylinder contribution and buzz test with the $20 dollop adapter I but off Amazon. Cargauge pro is the app you want. I'll post up the instructions from another forum/thread when I have a chance. Used it to figure out my harness was shorting out on the valve cover. It isn't the most intuitive piece of software, but once you get the hang of it, it can be quit useful.

lincolnlocker · Jun 29, 2015

ja_cain said:
I can do cylinder contribution and buzz test with the $20 dollop adapter I but off Amazon. Cargauge pro is the app you want. I'll post up the instructions from another forum/thread when I have a chance. Used it to figure out my harness was shorting out on the valve cover. It isn't the most intuitive piece of software, but once you get the hang of it, it can be quit useful.

sweet

live life full throttle

Yerkie · Jun 29, 2015

Yeah I know at this point I have to plug it up. I wanted to take a look for myself at the uvch and replace just as preventive maintenance later down the road. Now I just need the time to take it to someone I'll probably take it to the people I bought it from

Yerkie · Jun 29, 2015

Yeah I'm gonna take it in Wednesday to do a compression test and plug it up to the computer again to try to find anything out of wack. Last time I had it plugged up nothing was coming up wrong. As for the uvchs I just wanted to replace them as preventive maintenance later down the road.

I just hope I can find out what's going on cause it's just annoying and feels like it's slightly down on power

Yerkie · Jul 2, 2015

Ok so i had the truck in the shop and they ran balance test , contribution test and checked for codes and the icp/ipr duty cycle. What they found was on the balance test cylinders #5 and #8 failed at 2.0-2% if that sounds right and the duty cycle for the icp was 10%.

I talked with the guy and he mentioned running an oil rail pipe connectly the both oil rails to help the oil pressure run more consist on both sides. Also replacing the ipr to see if it was getting hung up whdn the engine got to temp.
Finally replacing injector #5 to see if the problem goes away.

What do you guys think any other opinions are welcome? Thanks!

Yerkie · Jul 2, 2015

I posted in the other thread i got going but i had the truck scanned, contribution test and balance tested.

Icp/ipr duty cycle was 10% but cylinder #5 and #8 failed the balance test they were coming up 2.0-2% if that makes sense.

Now i debating on running a oil rail pipe across the top, or replacing the ipr or injector #5.

What do you all think?

ghohouston · Jul 2, 2015

I wouldn't waste my time with the oil rail crossover. I'd fix the problem (injector (s)

Yerkie · Jul 2, 2015

To be honest thats what im thinking to hit the injectors first i just am wondering if the ipr could cause this or would it be visible on all injectors?

Arisley · Jul 2, 2015

I would think it would be noticeable on all injectors.

Yerkie · Jul 2, 2015

Thats what i was thinking for the overall im gonna be a pro at pulling those valve covers off at this point.

One question i had for you guys is if number 5 and 8 injectors are failing the balance test is that a common problem? Like a bad cps says makes 3 & 8 fail sometimes?

TyCorr · Jul 2, 2015

It cant hurt to run a balance line but whats really wrong? That in and of itself isnt an issue. Tons of modded trucks with isolated oil rails. No issues. Perhaps sending the whole set of injectors out to be inspected would be better. If you have the injectors isolated.

And you said compression test right? What were those #s?

ghohouston · Jul 2, 2015

Not that I've ever heard of. I'd say #8 is a toss up, and #5 is bad for sure.

Yerkie · Jul 2, 2015

I wish I was able to send them out but its my one and only daily driver, I never got the numbers off the compression test he just told me that everything was as it should be and nothing different then the other. Im going to I think hit the passenger side bank and take a closer look at #5 cause from what I have hear #8 being the last cylinder usually runs slightly more then the others.

someone correct me if im wrong

lincolnlocker · Jul 2, 2015

if number 8 has a LL or AE on it, its prolly not the injector.. they are known to throw off balance and is normal.. is called the cackle injector to make it sound quieter i guess.. what cps are you running? is it bone stock or tuned? if its bone stock then 5 might be bad. if its tuned, try switching tunes to see if 5 still fails.. did they do a cct or a rotational velocity test?

live life full throttle