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Yes, it looks like the timestamp is 3 decimal points. Easy mistake to make, no one's expecting that many decimal points. All of it is definitely idling so there may be another log or more lines in the same log for driving.
 

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Discussion Starter · #43 ·

I hope this works this time. This was a drive we took before the 3rd gear pull. My grandson pulled these from the AP. He probably didn't notice he only got seconds of the WOT pull. This one seems to have more info.
 

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Take this with a grain of salt because I don't have a lot of experience. It looks like there's an obstruction in the intake path. Also full throttle at 2k rpm is terrible for this type of engine. Rotating assembly can't survive lugging for very long. Less than 50% throttle below 3k rpm and stay between 3.5 to 6.5k for WOT.

  • Not enough air, at WOT especially at higher revs, MAF corrected should be closer to 200g/s while yours rarely gets above 90.
  • Ignition timing is 15-20 BTDC at WOT & 4k+ rpms. It should be low single digits. But again that follows higher airflow & boost so symptom rather than cause.
  • Target boost relative is 16-18psi at WOT which is pretty reasonable so atleast the ecu is not trying to reduce power actively.
  • Target and actual are closely matched for throttle & fuel pressure so both systems are probably fine.
  • Wastegate duty is ~40% which is pretty reasonable if the turbo is building 16psi boost but seems high for 2-3psi. But again not sure about this one.
  • Assuming the engine is warmed up, the different voltages on tgv don't make sense, maybe they are sticking?
 

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Discussion Starter · #45 ·
So it’s a tumble generator valve….could that rubber gasket that goes between the charge tube and intercooler that I found missing, get sucked the whole way into the motor and plug one of those? I have no idea, just always wondered where that seal went to.
 

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Given that the car ran fine for a while, it's possible the gasket ripped & pieces went into the intercooler or even further. I don't know how to look for it without pulling the intercooler, intake manifold and TGVs out. Both TGVs sit between the intake manifold and intake ports. It's a fair few hours of work and hunched over the engine. If you are up for that, you could knock out some preventive maintenance as well by replacing all gaskets & walnut blasting the intake valves which is due at this mileage anyway. OEM gaskets & harbor freight tools for blasting will cost under 150$ in total but it would cost between 500-800 at a shop.
 

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Discussion Starter · #47 ·
Well I dropped the car at the dealership on Monday morning. They called my grandson this afternoon and said both cats are clogged. Now I know I checked for excessive back pressure with a gauge in the A/F sensor on the front j pipe and it never came off zero. Temps with my heat gun seemed in line too but they said both are clogged. So he's just getting them replaced and see how it goes from there. I feel bad my trouble shooting wasn't better. I do remember thinking at idle there wasn't a lot of exhaust coming out of those pipes but I just figured it was normal, I'm used to a V8. So as of now they claim the new cats will fix it. I'll let you know once it's fixed if that was it for sure. I told him to tell them we're taking the old cats with us. We have a guy who pays nice money for the used cats down the road from us.
 

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Thanks for posting the update. Do they have any theories as to why the cats got clogged? Incorrect tune maybe? It's very unusual on this engine.

Don't feel bad lol, it's one of the most uncommon problems for this engine and you got close enough with the idea that something is clogged in intake or exhaust.
 

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Discussion Starter · #49 ·
Thanks for posting the update. Do they have any theories as to why the cats got clogged? Incorrect tune maybe? It's very unusual on this engine.

Don't feel bad lol, it's one of the most uncommon problems for this engine and you got close enough with the idea that something is clogged in intake or exhaust.
They didn't say why as of yet. I'm thinking they may have been on the way out when he got the car because it had a brand new A/F sensor installed and he had to get a new maf sensor the morning after he drove it home. It had the first 93 tune he called it put on with the AP and didn't mess with it until it quit boosting. He's wondering if leaving it warm up too long caused it. He said he waited till the water temp was up to 190 before driving. I had told him once it idles down he should be able to get going but he warmed it up every time.
I did think it was clogged but the dang gauge not registering back pressure made me second guess myself. We will cross our fingers that this corrects the issue. If it does I'll be relieved it's not an engine issue. He already had this short block picked out somewhere online that had better rods, etc. Lol. I wasn't really looking forward to pulling that motor. Haha.
 

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Idling won't cause clogged cats, not unless there's a major problem with tune or fuelling. Maybe that missing gasket made it run rich or lean and damaged cats.

Highly doubt anyone waits for it to rev down, much less warm up before driving. Long as you don't do WOT to redline on cold oil the engine will be fine. 170F+ on oil is enough, water temp doesn't really matter.
 

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Discussion Starter · #51 ·
Idling won't cause clogged cats, not unless there's a major problem with tune or fuelling. Maybe that missing gasket made it run rich or lean and damaged cats.

Highly doubt anyone waits for it to rev down, much less warm up before driving. Long as you don't do WOT to redline on cold oil the engine will be fine. 170F+ on oil is enough, water temp doesn't really matter.
New cats are on and car runs great! They said it was in limp mode and that was the engines way of protecting itself. We reset that ecu multiple times with the Cobb AP but not by undoing the negative battery cable. So I don't know for sure but it's running great! Thanks for all the help.
 

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Discussion Starter · #53 ·
That's good to hear. Did you ever find the missing gasket?
Nope. I'm picking up the old cats Monday at the dealership. They tried to pull a fast one on my grandson and said they needed to keep them. That is true on warranty cat replacements but not when you purchase on your own. So I called and said I'd be by to get them. Service manager put me on hold and said he had to go find them. I was on hold 15 minutes. I bet somebody already had them loaded up. haha. I'll look inside and see how they look. Could that gasket have melted in there? Lol. I'll let you know.
Another note on this issue. In all my searching online about no boost there was one article that kept popping up. It was a guy who had just bought a salvage wrx and it wouldn't build boost. His answer was he replaced both cats and it then built boost. So I should have tried more troubleshooting on the cats I guess. Just glad it's done!
 

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Nope. I'm picking up the old cats Monday at the dealership. They tried to pull a fast one on my grandson and said they needed to keep them. That is true on warranty cat replacements but not when you purchase on your own. So I called and said I'd be by to get them. Service manager put me on hold and said he had to go find them. I was on hold 15 minutes. I bet somebody already had them loaded up. haha. I'll look inside and see how they look. Could that gasket have melted in there? Lol. I'll let you know.
Another note on this issue. In all my searching online about no boost there was one article that kept popping up. It was a guy who had just bought a salvage wrx and it wouldn't build boost. His answer was he replaced both cats and it then built boost. So I should have tried more troubleshooting on the cats I guess. Just glad it's done!
Sounds about right for dealerships lol. The gasket was on intake side so if it's still there it will be stuck somewhere in intercooler.
 
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