Chevy 8.1 Engine Issues Again!

[kcgaz]

I posted last year regarding our Chevy 8.1 Workhorse engine going into limp mode, well it happened again today while pulling a hill and towing our toad. Prior to it happening, our rig just acted like it had little power. The gas sat through the summer, with Sea Foam, is it possible that this could be the problem? Any ideas, experiences and/or advice is appreciated as always!

[wa8yxm]

I remember once having some engine work done.. Idiot left the blang sensor (MAP or MAF forget which) not hooked up.. Got that fixed.. and several years later I'm going down the road and suddenly Limp mode. Said sensor is the very first thing you see on that car when you look at the engine, he'd left the vacuum line off.

Several years later the car went into limp mode. I pulled off freeway read the code, called the mechanic and he told me "that's in the emissiions control area" I said "Thanks" .. the other end of the same vacuum line.

[ArchHoagland]

Had a similair problem which was intermittent at first and then pretty frequent.

Common wisdom on here said fuel filter. Had it changed $150. No help.

Next common wisdom said O2 sensor. Changed myself $100. No help.

Research suggested cleaning the MAF. Problem solved.

A can of MAF cleaner is $10.

[babock]

Hobo X 2 wrote:
Check engine light came on

Next time pull the code to see what is wrong. Might help you actually permanently fix the problem.

[Hobo_X_2]

This same problem happened to our 07 Voyage. About 20 miles down the road after getting fuel in Clayton NM power dropped. Pulled over removed fuel filter, drained, then reinstalled. I had just put new fuel filter on about 500 miles before. RV would get up to about 30 then rpm would drop. Went through process again, same results. Check engine light came on, I stopped and removed negative cable, operated lights, ignition switch, ect. Hooked battery back up and rig ran fine. Got to Raton and bought some Lucas Oil Fuel Treatment. For the next two or three fill ups I added Lucas Oil. Fortunately I had only purchased about 25 gallons in Clayton. By removing DC power the computer was reset. Now I add Lucas Oil periodically.

[RLS7201]

enblethen wrote:
the potentiometer is called the "throttle position sensor"

Thanks Bud, I was having brain fade when I posted. Yawn..........

Richard

[enblethen]

the potentiometer is called the "throttle position sensor"

[babock]

The burning of the oil degrades the O2 sensors. Same thing happens when an engine gets older and starts burning oil. Why would you want to do this on purpose?

Of course they are going to say it's safe for sensors! LOL SeaFoam came out long before O2 sensors were installed on vehicles. If your sensor lasts half as long using SeaFoam, you think you are going to be able to blame them for it?

Use something that actually works that has PEA in it like Techron. SeaFoam is a mixture of Oil, Naptha and Isopropyl alcohol. Gasoline already has a high percentage of naptha in it which is the only solvent in it actually doing anything.


BTW..there is no stabilizer in the world that will prevent phase separation. If you are getting enough water in your tank that you would get phase separation, you need to buy your fuel from a different source.

[RLS7201]

Back at the onset of the 8.1 Workhorse chassis, there was some issues with accelerator peddle potentiometer failure, causing an issue like yours. The potentiometer can be checked easily with an old analog ohm meter. Attach meter to potentiometer and slowly move potentiometer while watching meter. A smooth action of the meter hand would indicate the potentiometer is good. If the hand wiggles the potentiometer is bad.

Richard

[wa8yxm]

The 8.1 is one very built engine.. Basically you need to work hard to kill it.

My history with it.
Purchased in 2005. drove with only one issue till 2014 (Rodents chewed some primary (12 volt side of ignition) wires and it was missing on two cylinders. 2 new P-Tip spark plugs a bit of solder and tape and 100% again. Wife could not even hear the misfire but my ears are ... Well I am part mechanic.. Not fully trained, but trained non the less).

2014 It got murdered.. By that I mean the motor was KILLED by an external disaster

2017 Got enough cash on hand felt comfortable repairing.. put in a '04 and as of last Tursday.. Still purring like a kitten.. NOTE.. The gas, over the 3 years it sat, was used slowly by the monthly generator exercise and by a couple of power outages that did not bother me at all (like Hurricane Matthew which passed.. Far too close for comfort).. But the engine still purrs like Kitten.. Oh, I did Sea Foam it when I parked it.

During that time across from me was another 8.1. Been sitting there a lONG, LONG, LONG time. so long in fact the batteries would not even accept a charge.
Dropped in a new chassis battery.. Turned the key.. Kitten time again, Ran like new.. that gas was at least 5 years old and no seafoam either.

Hard to kill that engine.

Now dirty fuel, Dirty filters. Bad plugs, Rats in the wiring.. and bad sensors can cause issues.. I did have one "bad sensor" issue but.. Well that was a sensor of the 2004... (We reused the old sensor because the new one seals up different and it is in an oil present area) Tarnish on the connector pins.. Unplugged and re connected a few times and KITTEN TIME once again.

[tarnold]

Well, Seafoam can be bad on 02 sensors. Loaded up my 6.8 E350 with Seafoam, and, and within 20 miles it had knocked enough crud loose to cause a check engine light, "faulty 02 sensor".

[SidecarFlip]

babock wrote:
SeaFoam is 50% oil. Don't use it with engines that have O2 sensors.

Use something with PEA in it like Chevron Techron if you want something that is a fuel injector cleaner.

Another 'opinion' post. The net is full of them and most opinions are full of...

Says on the bottle 'safe for emissions engines'. Don't think the manufacturer would chance getting sued for false advertising.

Having said that, I tend to side with Mr. Wizard, Sea Foam isn't a good e-gas stabilizer, it has nothing in it to prevent phase separation.

Good injector, intake tract cleaner however. I use it regularly. I do not use it for e-gas stabilization.

[Bruce_Brown]

Sounds like a classic sign of lack of fuel. I'd check the fuel filter, fuel pressure, and try some fresh, high octane fuel.

Also, as has been asked, did it set off any codes and/or lights.

[newman_fulltime]

ArchHoagland wrote:

babock wrote:
SeaFoam is 50% oil. Don't use it with engines that have O2 sensors.

Use something with PEA in it like Chevron Techron if you want something that is a fuel injector cleaner.

Hmmm. I put five cans of Seafoam in my tank once a year before a long trip. I use it in both my cars.
All of them have O2 sensors.

Could you explain why you think that's a bad idea as I've never had a problem?

Seafoam does not hurt sensors

[ArchHoagland]

babock wrote:
SeaFoam is 50% oil. Don't use it with engines that have O2 sensors.

Use something with PEA in it like Chevron Techron if you want something that is a fuel injector cleaner.

Hmmm. I put five cans of Seafoam in my tank once a year before a long trip. I use it in both my cars.
All of them have O2 sensors.

Could you explain why you think that's a bad idea as I've never had a problem?