8.1L burping, coughing, what?

[ramblinboy]

At 3K and 4K RPM the engine sneezes, coughs, burps.
What in the wide world of sports is a goin' on?

["007"]

I would check your spark plug cables for burnt wiring replace with Taylor insulated protected ones.

[ramblinboy]

Originally Posted by "007"

I would check your spark plug cables for burnt wiring replace with Taylor insulated protected ones.

Thank you for the considered advice. What is going on in the ignition process?
Is it backfiring thru the carb? Is there a carb in FI?
Should I stick with OM parts or upgrade to modern application?

[1mainiac]

No carb on a 8.1 Could be a fuel filter which is on the driver side frame rail near the trans. Plug wires would misfire at any rpm so not likely them. Any lights coming on in the dash? Most mis fire issues I have fixed have been cam or crank position sensors they are not real hard to change but will give you many odd symptoms. If it were in my old shop I would hook up the Tech II and go for a drive and read any miss fire data. Another issue was TAC module which is under the dash on the left side of the steering column. This will cause the engine to receive wrong throttle info which can cause it to run lean and cough.

[ramblinboy]

Hmm TAC module eh?
Should I pull it and have it replaced?
Im 200 miles from home approaching Helena Montana

Originally Posted by 1mainiac

No carb on a 8.1 Could be a fuel filter which is on the driver side frame rail near the trans. Plug wires would misfire at any rpm so not likely them. Any lights coming on in the dash? Most mis fire issues I have fixed have been cam or crank position sensors they are not real hard to change but will give you many odd symptoms. If it were in my old shop I would hook up the Tech II and go for a drive and read any miss fire data. Another issue was TAC module which is under the dash on the left side of the steering column. This will cause the engine to receive wrong throttle info which can cause it to run lean and cough.

[gunnut]

Sounds like a lean condition if it is doing it at higher RPM's. If you are lugging under load does it do it? Is the sneeze cough or burp a backfire out of a tail pipe. Read my posts under 8.1 missing backfiring, and It's baaaack missing backfiring. Mine was a short in the coil wiring harness on bank 2, and later a loose plug wire. If you have a scan gauge or ultra gauge set it to read your short and long term fuel trims. When mine misfired, I was able to isolate it to bank 2 by watching the trims sky rocket. By the coil wire shorting out, the O2 sensor was trying to compensate, and would enrich the injectors on that bank, and it would backfire. Check the obvious first, plugs, wires (make sure they are tight on the plug), change fuel filter, and clean MAF sensor. Some people on here have also had same problem with a gummed up throttle body. I have also heard of crank position sensor doing same thing on pre 06 8.1's. One other thing to try, is open up the dog house at night and see if any of your plug wires are arching. Sorry for throwing out this much info., but I have been in your shoes and it is nerve racking.

[Brazel's RV Performance]

Spark plug wire(s)

[garyspang]

Hi ramblinboy
Use Techron to clean up the cylinders and plugs, then see if the service bulletin in the second link applies to you.
Oil mist may get into your intake manifold past the thick elastomeric manifold gasket and cause carbon deposits on your valves, plugs and upper cylinder. This will cause pre-ignition and backfire through the intake manifold. Oil consumption is not yet excessive as claimed in the bulletin. After I fixed the bolt tension issue, Techron was no longer needed and the engine runs like new for the last 13,000 miles.
http://www.irv2.com/forums/f22/8-1-l-vortec-misfire-and-ping-solution-non-plug-wire-issue-114150.html?highlight=garyspang


http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=49&cad=rja& uact=8&ved=0CE8QFjAIOCg&url=http%3A%2F%2Fwww.irv2. com%2Fforums%2Ff22%2Fpossible-cause-for-8-1-l-vortec-misfire-and-ping-solution-non-plug-wire-issue-221134.html&ei=t4KCVfyrKcn1oASJkIOgDw&usg=AFQjCNHJ WSI7PLXy5nMurRrcP1fayO_R8w

[az bound]

I suggest starting with the easy things first. Clean the MAF and check the filter.
New fuel fiter.

[dieselclacker]

Sure sounds like a plug wire. I would check last two wires on drivers side (5 and 7) first, as these two are known to be problematic on some chassis.

[ramblinboy]

I have filled up at Conoco who use Techron and added a small bottle to my 75G tank. Still there at 3&4K when climbing. Ill start with plug wires and fuel filter and get back to you. I have 53K on the engine and it purrs like a kitten otherwise. Love those 6 gears!
Thanks for all the input, rB

[Fred and Bonnie]

Originally Posted by ramblinboy

I have filled up at Conoco who use Techron and added a small bottle to my 75G tank. Still there at 3&4K when climbing. Ill start with plug wires and fuel filter and get back to you. I have 53K on the engine and it purrs like a kitten otherwise. Love those 6 gears!
Thanks for all the input, rB

Fuel filter change should be changed every two yrs. Your miss while hill climbing is a classic Sparkplug/Ignition wire failure indication. I would suggest high temp wires, such as Taylor's and replacing the plugs with AC Delco Iridium. I have found that at about 5ys mine start to act-up.

Fred

[allen1947]

I have a 2003 Holiday Rambled Vacationers, W22 Workhorse and has 16,450 miles. I have driven to Fall Creek Falls State Park in Tennessee many times over the years up state rout 111/8 highway, fairly long pull and never had a burnt plug wires. But talking to other workhorse chassis owners, some had the problem some didn't. After looking at several different (brand) coaches makes I can see the problem. My coach if you look over the front tires you can see the whole side of the engine on both sides. It's obvious that is the reason my coach has not had that problem. If I owned a coach that you could not see the sides of the engine I would consider buying the cooling kit from workhorse. If you are like myself I would figure some way to build my own air routing piping. Another though about high temperatures in engine bay. Five years ago when I first begin to have brake caliper problems I purchased a wireless temperature reader from Sears for around $50.00 and when I smelled burning brakes I pulled over shot the infrared beam at the rotor, sure enough I found the one. By the way those temperature readers can be bought now for half what I paid at Harbor Fright. Well that's my thoughts hopefully it can help someone. God Bless

[BEBOP]

I bought me a temp gun too for the same reason. Bebop