Engine trashed?

Well here's the facts.

The truck drives like it's starving for fuel. Bogging, weird idle, can't handle heavy loads. Throwing a permanent code of P11F1.

The truck has a procharger installed and it ran fine for about 6 months. Then I started to get air/fuel ratio codes on cylinder 6. Stuck it in a trusted shop in January. They performed a compression test and found that cylinder 6 was 90 while the other cylinders were 150. They determined there was a leak in the exhaust valve. So I opted to have them lathe some upgraded valves and replace the intake valve with factory ones while at it. 7 months later the engine was back together and the compression of cyl 6 was up to 120. So I pick it up and drive it for a day only to return it again on the next day. It was still struggling under load especially in 3rd and when giving any boost. Still had cylinder 6 air fuel mix codes. They continued diagnostics for another month. Scoped the cylinder - didn't see any scarring. Smoked the intake - found no leaks. inspected the injectors - all seemed good. Air could be heard passing into the oil pan area. The assumption is rings could be bad causing 120 compression instead of 150 like the rest of the cylinders. They want me to get a new motor.

I asked them to swap the injectors with another cylinder. Then I picked it up. Last Friday I got it home barely. I had multiple misfire codes, flashing engine light, couldn't make it up a hill going home had to restart the truck, struggled to accelerate. So at that point I'm thinking fuel pump, tune or spark plugs.

Last night I replaced all the spark plugs and ignition coils. Today I drove to work and although no misfiring I could tell there was a lack of power and felt like a lack of fuel. I took it easy staying out of the boost too much and I avoided 3rd gear. When I got to work (about an hour drive) I had no engine light but decided to hook up my OBD2 reader. Sure enough there was a permanent code for P11F1 and a temporary code for P11F1 (air/fuel ratio imbalance cyl 6).

On my way home I'm going to unplug the upstream O2 sensors. Maybe it's going bad and causing issues in the 120 compression cylinder and not the 150 ones. Idk I've got so much repair into this motor I hate to just get a new one. The truck I loved 9 months ago is a truck I'm willing to scrap just to see it crushed. It's sickening. 70k miles on the truck. You can buy them with superchargers from the factory I can't imagine that having an impact on it. Plus it's a centrifugal so it's not even that aggressive of a supercharger compared to the ones from magnuson being a roots blower.

Anyone have any experience with this. I have a hard time finding compression values for these trucks but I seem to see somewhere that you want between 120-160 compression and even though this cylinder is on the low end it should still be able to handle the compression, shouldn't the boost also help that cylinder compress if it's losing air since it wouldn't be losing air fast enough to reject the boost? I'm wondering if the imbalance is fuel and not air. If there's anyone local to North GA or even someone remote that can look at data logs or see what my ECU is doing to assist that would be great. I reached out to OTT tune to see if they could assist as well as their local qualified tuner near me which is CRS Tuning in Flintstone GA but still waiting to hear back from either of them.

I'm sure most people will say the code is persistent with cyl 6, it's got to be compression. But is there a chance the tune is just out of wack? It would be very helpful to have another set of experienced eyes on the ECU as it runs.

Edit:
Originally I've was solely focused on the cyl 6 air fuel mix codes. After discussions here it seems as if that's less of an issue and the cylinder 4 misfires causing limp mode is more important. My focus has tuned to this code to be resolved before tackling the air fuel on cylinder 6.

 

Who sells prochargers? Start with them.

 

They aren't helpful lol. Basically a "you got yourself into this figure it out" attitude.

 

That's bs unless there is no way the procharger is to blame which may be the case.

 

Even if they are to blame what can I expect them to do about it? It's almost 2 years old. They didn't install it. There's no warranty. I can blame procharger all day long but it's not going to get the truck fixed lol.

 

They might have insight as to the engine tune if that is the issue

 

Ah, I'm actually currently running one of yotawerx tunes. I was a tune tester for them early on. Then had the cylinder air fuel mix issues. Inquired if they had a new tune. They stated there was a dyno tune they did that was a lot different then the one I had. Even after that was put into the truck I was still having issues with air fuel mix codes on cylinder 6. It's possible the first tune caused damage but who knows. Only real good way to tell is knowing what the raw data is going into the cylinder to see if it's a loss of compression or lack of fuel. Im not sure what those numbers should read.

 

Good luck it sounds like a mess

 

Seven months to do a valve job on one head?! After they put it back together, why didn't they do a leakdown test? That would give a better idea where the compression is going. Could be a head gasket leak for all you know.

Good luck.

 

prochargers = fix it yourself

 

Seafoam?

 

Tell me about it lol. They did a leak down and said it was in the cam area and no longer in the valves. So I guess it's piston rings. But is 120 compression low enough to cause the truck to limp?

 

LS Swap

 

Might be the move.

 

Who in the hell is doing this work, the Three Stooges? Leakdown says it's in the cam area means bad rings?

I would think it would run fair with 120# compression, but you'd possibly be seeing bad readings from O2 sensors due to poor burn in #6.

 

"Air could be heard passing into the oil pan area" - if this diagnosis is accurate, you have ring issues (maybe broken) with that cylinder. Regardless, the PSI needs to be within 10% of each cylinder and preferably much tighter than that (<5%). I would say an engine tear down is in order.

 

Lol. Truck drove home better with the O2s unplugged. Didn't handle boost well but I'd say that would be expected.

 

What a bummer! I guess I'll be on the look out for an engine...

 

Getting a quote from Toyota for piston ring replacement...pray for me