GM 8.1 choking Out?

[Jyrocharlie]

It's a gm service bulletin. I have never seen a part number for it. I made mine when I had a 89.

[Champs]

It does have air deflector. thanks

[Champs]

Originally Posted by vettenuts

What happens if you warm it up fully before driving, does it still do it? If not, sounds like an open loop issue.

Did you install the Workhorse MAF or an aftermarket? If aftermarket, the calibration may not match the original. Do you still have the original you could swap and verify?

It was aftermarket...I will unpug and check to see if problem goes away. Thanks!

[Champs]

Originally Posted by Jyrocharlie

This fixes that air flow problem. it can also prevent a cracked manifold from over heating. I don't know how many years of 454's had this problem.

I do have air deflectors in pace. thanks

[Champs]

Originally Posted by DiverBob57

Have you had the O2 sensors checked? Also, there is a Workhorse forum with several 8.1 experts that can offer suggestions.

https://www.irv2.com/forums/f22/

They were checked out when i first got it...500 miles ago but will check them out. Thanks

[Champs]

Originally Posted by RS505

Fuel Filter?

fuel pump and fuel filter was just changed. Fuel pressure is good.

[Champs]

Originally Posted by Unplanned

Get a "ScanGaugeII" and watch your numbers for fuel trim and also the MAF flow.

If you have good power once you are going down the road, your cats are fine.

With that much oil and junk in the intake, I suspect your MAF is dirty again. Give it a cleaning with MAF cleaner, and try it again. It doesn't take much to cause them to give false readings, and send a lean fuel mix. If you run it too long on excessively lean mix, it will destroy your engine.

The maf was just changed with aftermarket sensor...no miles since so still new and clean. What would cause oil to be accumulating on outside of air filter housing or too many possibilities to list? Thanks

[Champs]

Originally Posted by vettenuts

What happens if you warm it up fully before driving, does it still do it? If not, sounds like an open loop issue.

Did you install the Workhorse MAF or an aftermarket? If aftermarket, the calibration may not match the original. Do you still have the original you could swap and verify?

I did intstall and aftermarket maf...that might be the problem. I know when i removed the old maf and air filter the air filter was completely clogged and full of opil residue. I havent tried letting it run for 10 minutes before driving but will try that. Thanks

[Wrenchch3]

If you don't install the MAF at the same angle as you took it out. It will cause this problem

Originally Posted by Jyrocharlie

Unplug your mass air, If the problem goes away, the mass air is your problem.

[Wrenchch3]

Meaning the wire hook up to MAF angle as old one

Originally Posted by Wrenchch3

If you don't install the MAF at the same angle as you took it out. It will cause this problem

[Champs]

Originally Posted by Wrenchch3

Meaning the wire hook up to MAF angle as old one

Thanks

[Champs]

Originally Posted by Wrenchch3

If you don't install the MAF at the same angle as you took it out. It will cause this problem

That is interesting. Cant say its at the exact angle but will disconnect and try that. It is a Blue streak maf...will that make a difference to since its not a workhorse maf? Thanks

[hydro45640]

Forget what you have been told so far. Take your motor home to a shop for a computer diagnosis. They will give the answers.

[VanDiemen23]

Yeah - read the codes. But why in the world are you changing so much stuff with just 22,000 miles on the clock?

Plugs would have gone 75-100K, MAF - rare failures, coil packs - really? Fuel filter and pump at that mileage?

I suppose there are some long term storage/lack of use issues that can come up but throwing that many parts at an engine that will go 100K with nothing but oil changes (and the aforementioned plug wire issues) is just introducing the potential for screwing other things up inadvertently.