Runs rough under load

[max49]

The high dollar ($85.34 w shipping)10.4MM "Taylor 409 Wires" from Summitt Racing have 79286 on the box. I have 5 of them left and they look really cool. I have lots of experience with burnt wires and IMO they are glitzy and would look great on cars at the Barrett/ Jackson car auction.


I am sorry but these wires are much bigger insulation around the wire but rubber caps are terrible. They never lasted any where near as long the cheap AC Delco style wires. The last one burnt/ melted in less than 50 miles going across Monarch Pass.
Any auto parts store will have wires, just ask for them for a 3500 Chevy pick up with the 8.1. ($20-$30)
Keep spares because this problem is reoccuring unless you find what you need to get the heat out from back there. I put my 2nd bilge blower on the right side of the engine, but it has'nt really had a good test yet.
All my burnt wires were #5 and I put a blower on it. Then the burnt wire moved to the other side ,#6, so I put another blower on that side.
Seems these 8.1s need a lot of heroic life support measures. Some of the lucky ones got free ventilation kits under warranty but Workhorse picks the 'haves and the have nots' and I was chosen to fend for myself. They replaced one, as in 1 wire under warranty and after that I figured it was not worth the time, gas and inconvenience of taking the MH in for them to take 2 minutes to change 1 SP wire.
Definitly call Dale OEMy to get exactly what you need for your fuel filter, he'll get it to you in a couple of days.

[ctpres]

If above no help - check O2 sensor. Just went thru what you describe and that was answer to our problem.

[carguy]

If you put on new wires you should go ahead and change the plugs while you have the wires off. The plugs usually have fouling from bad wires and for the small price of the plugs it will make sure you don't have to take it back apart.

[garyspang]

[QUOTE=IrishRover;1069569]Greetings,

I have a 2007 Adventurer with a Workhorse chassis. My main issue is when on the highway and putting the engine under a load (going up a hill) as the downshifting occurs and I then feed in the gas pedal, I am getting a popping and bucking going on until I ease off on the gas pedal.

I had the same problem (2003 GM 8.1L Vortec). Replaced all known sensors to no avail. Culprit were deposits left behind on valves, plugs and cylinder walls. Inspect your plugs for any deposits. Problem surfaced about 30,000 miles after ethanol was added to the gas (101,000 mi at present).
My solution was not instant. It took over two years of experimenting. I will tell you my process.
0. Increased fuel rail pressure by 10 psi for 0% injector boost, as per lap-top display, at 60 mph: no improvement. Setting retained.
0.5 Replaced all sensors. No improvement.
1. Used 3 cans of aerosol SEAFOAM at throttle plate. Partial cure
2. Continued use of SEAFOAM fuel additive: no further improvement.
3. Used OTC 7448 www.otctools.com fuel rail injector with professional fuel injector cleaner: no improvement.
4. Used MARVEL MYSTERY OIL as a gas additive: Problem got worse, re-cleaned with aerosol SEAFOAM.
5. Used Z MAX gas additive in the OTC 7448 fuel rail tool along with gasoline: noticeable improvement.
6. Continued to use Z MAX in gas tank and oil (after oil change): gas mileage went up by 0.5 mpg but no further improvement. Still use it in oil.
7. Used TECHRON CONCENTRATE 20 fluid oz with gasoline in the OTC 7448. Problem solved 99% . Occasional ping occurs, but that is supposed to be normal.
8. Am using 20 oz TECHRON CONCENTRATE in every 80 gallons of fuel as a preventative measure. Engine runs like newunder all load conditions.
Bought two cases of TECHRON CONCENTRATE on sale at half price. Good bye to pre-ignition and intake manifold backfire.

This was a most frustrating experience, but with about 12,000 gallons of fuel with questionable locally added ethanol passing through the engine something like this is of no surprise.

[Coached]

I can't tell you how many times I've given this bit of advice. I had an '05 Adventurer with the 8.1 Vortec with the Banks set up. I experienced various problems with it and had hoped that the Banks get up would address many of them. Wrong. Banks did increase performance but did not alleviate any of the other things. I went to one of our local "hot rod" shops, you know, a place where they make all kinds of cars go really fast and do all kinds of other crazy things. Many of these shop owners use RV's to pull trailers with cars on 'em to go to the races. They are used to investigating, analyzing, fabricating, installing, and testing a whole bunch of different methods and combinations that are required to work under a whole variety of situations!? These Guys, for the most part, know their stuff and, usually, are pretty enthusiastic about a challenge from a "motorhome guy"? I was surprised how many motor homes and fifth wheel pickups I saw while there. Yes, they did make a variety of changes, not many of them that were real big either, but the results were great. And they're there either at the end of the phone line, or in person when I need them. Saves you allot of time, experimentation and frustration and usually provides better results?

[garyspang]

[QUOTE=IrishRover;1069569]Greetings,

Hi IrishRover
Your description fits the issue that was solved in the following post: "8.1 L Vortec misfire and ping solution (non plug wire issue)"

By garyspang