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I don’t see any issues. 15 minute swap back to the factory MAF especially since you are reusing the stock bubble. Just unbolt the CF merge, filter, box, and bolt in the stock MAF. If you don’t have a filter don’t worry about it since you may not be going out to drive it. You’re just running it in the garage but need to determine why it is so rich with correct injector corrections. Swap stock injectors back in. Leave the GM MAF in place just disconnect from the MAF plug. Super simple to go back to stock known good injectors, MAF, and no extra fuel control. See how it runs after that. I guarantee it will save you hours and hours of work. Also, plug that hose nipple on the front pre-turbo pipe that used to be there for the charcoal canister.
 

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Discussion Starter #22
My catch can vent taps into that pre-turbo nipple . That was a picture taken months ago , before everything was back together. I have installed an aluminum air box , so swapping the old MAF back in isn't a 15 min job, not to mention I need to pull the manifold back off to get to the injectors, but I can do it. I should have the new MAF tomorrow, so I want to try that as my last effort before going back to stock . I understand what you mean about returning to a known baseline and not just throwing new parts at the problem. I have zero confidence in the MAF's I have though, so nothing to loose by replacing that part . I know one came off a junker, as it has grease crayon from yard on it. Other one looks brand new, but doesn't have any markings on it to indicate its not a Chinese Knock Off. I bought the 660 injectors from a reputable source and they came with testing documentation, but who the hell knows for sure ? So, Im not ruling those out yet either , but I will go to stock before just replacing those willy nilly. I realize even if new MAF improves things, it may not totally solve low AFR #'s.

Also , I have to be totally honest here , and this is for anybody reading this thread for tips in the future, I can't swear that this car was 100 % before the upgrade. The last time I drove it , it suddenly lost power above 3,000 rpm . I was a few miles from home , and able to limp home with it, and manuever it in and out of garage , but the car was acting like it had a boost leak. I assumed I had a bad turbo, at the time and made the "HUGE" mistake of beginning my upgrades before correctly confirming the cause of the problem. Once I started unbolting everything, I found that the nipple on the back of the plastic OEM Y pipe had been epoxied back together at some point. It appeared to have broken off again , and I decided to press on , assuming that was causing a major boost leak , and the route of my power loss. I still think that is the case, but in full disclosure, something else might have been going on. I regret this decision , especially now , having spent 2 years listening and reading how tricky diagnosing these cars can be.

I'm about to head into another winter , so in truth there is no reason to be carelessly hasty, but after getting so close, I really want to figure this out. Somewhat glad I have at least one person throwing up caution flags and steering me in a logical direction.
 

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One fix at a time
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You might want to try at least swapping the stock injectors in so you don’t have to do any fuel correction and then mess with the MAFs. It will run in limp mode either way but at least it won’t be drowning in fuel. The GM MAF/MAFT will run with stock injectors as well. It’s possible your latency values are extremely far off and you could start messing with those as well as the scaling, but it would be nice to make sure everything else is working properly first.
 

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You're not going to get it running right until you've confirmed you've got stable fuel pressure. There's about 4 tests to go through. The first being that when it's idling you'll see 43 PSI on the gauge with the vac line removed. When the vac line is reconnected it will drop to 33 PSI. That's how they all are when they roll out of the factory. When you fit a bigger pump and hotwire you mess it all up. Every time without exception.
 

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Discussion Starter #26
You're not going to get it running right until you've confirmed you've got stable fuel pressure. There's about 4 tests to go through. The first being that when it's idling you'll see 43 PSI on the gauge with the vac line removed. When the vac line is reconnected it will drop to 33 PSI. That's how they all are when they roll out of the factory. When you fit a bigger pump and hotwire you mess it all up. Every time without exception.
I had always planned on verifying , the fuel pressure was correct. I installed the fuel pressure gauge , so that I would always be able to monitor it. I am not saying that I am relying on that one gauge to be accurate at the present, but it appears to be working . After my present situation , I am most likely going to add another AEM pressure gauge in the dash ( if I can find room!) , but I’m not going to get sidetracked on that. I’m hesitant , to continue with running this engine rich, as Turbo Since Birth has warned. Perhaps a quick test to see what happens to the fuel pressure with a vac line removed wouldn’t hurt . I already did a test on the coil packs , and they checked out. I started to do a PTU test earlier, but it was hard to get alligator clips on the ptu harness , so i never completed it. I have a spare motor from a NA car, so I’m going to harvest a spare connector to make a pigtail that I can use to connect the PTU to a meter & D cell battery.

I’m also in the process of gathering the old injectors & oem MAF to reinstall those to get back to a baseline. I guess I might as well but the original plugs back in . I had upgraded to a colder plug , but , I would think that is more relevant at boost conditions , than idle , but maybe someone has a different view on that.

I’m also going to map out the fuel & air circuits on paper , so I can do an inspection on relative wires and connectors to possibly find an issue there. I’ve witnessed brittle plastic harness connectors in other places , which is common for an old car.
 
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