Poor acceleration, shifting

dnsherrill

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I've put this up on other boards and wanted to confirm some observations, maybe get different ones
1998 LSC- Jmod with 1-2 lower, 2-3 springs removed, 126k miles, no CELs,
Awhile back I got a custom xcal2 tune which highlighted the fact that my car is running poorly. When I go wot, my foot does bounce a little at times, that's apparent on the graphs. Most of these SCT xcal2 data capture loops will be with stock tune, some will be the custom tune, some will graph o2s, IMRCs, short term fuel trims, etc. :

https://www.youtube.com/watch?v=SXVTlU1rXpM
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https://www.youtube.com/watch?v=BIDEE9ZbXUs
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https://www.youtube.com/watch?v=R1HFKUyFE8w
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tach and speedo, stock tune
https://www.youtube.com/watch?v=St4MTcvE_ac
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tach and speedo custom tune
https://www.youtube.com/watch?v=1uZ9nzLRkIw
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fuel pressure gauge, startup to normal driving, each large number is 10 psi (10, 20, 30, 40 etc)
https://www.youtube.com/watch?v=5SYq-gkNFhY
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more fuel pressure gauge normal driving
https://www.youtube.com/watch?v=aiTWFD7ZDfE
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so far, it looks like my air flow rate is very low (about 5/8 what it should be)....and there's a strong likelihood the imrc's are not opening. I can move the pass side by hand IMRC lever with little effort. It's also been suggested I have a bad fuel pump. Occasionally after driving it hard, I stop the car, get out, get back in and smell gas. I need to confirm IMRCs are opening, or wire them open and do more test runs. Also suggested a possible vac leak, clogged cat, or a faulty PRNDL- however when I reassembled after jmod, I took extra care to get the rooster comb right- it was definitely right when I reassembled vb; recently replaced air filter, fuel filter with no obvious changes
 
went to my local parts store and scanned for these DTCs
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DTC1_zps5d19qhke.jpg

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DTC2_zpsdqoe4mzh.png

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DTC3_zpstxztodly.png

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I'm starting to think I could have a bad PCM...?
 
i think i am of the opinion that your tune sucks.
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It's worse with tune, but is that because it's not running right with stock tune? I'm trying to figure out what needs to be resolved running stock strategy, I can't tell anything about the tune until then....also noticed yesterday, more than before, inside the cabin has a strong smell of gasoline after driving about 10 mins,most noticeable with AC on.
 
Finally made time to get under the hood last night:
cleaned MAF sensor, new PCV (old was gunked but still rattled), new plugs (some oil on drv side plugs, #6 the worst)
Seafoam through brake booster port at back of I.M. ....recent new air filter and fuel filter
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also, I was able to squeeze my left hand onto driver's side IMRC cable then linkage and move it....the bare cable feels slack, but the plates move manually...there are no CEL's... I'm thinking it's got slack because it's not closing all the way?
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after Seafoam, a great white smoke event, and it ran a WHOLE lot better-chirped tires and ran like a scalded dog, the numbers on the DLF xc2 today are not much different...abnormal bank 2 IMRC, very low air #/min
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I may try another Seafoam...but will likely end up pulling IM to clean IMRC's...never done it before, a walk through would be appreciated
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the first clip shows IMRC numbers before seafohm, I was parked revving the engine, then drove a bit, this also shows manifold vac and MAP
https://www.youtube.com/watch?v=FjmOmjuCqYw
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the second clip is running data this morning, normal driving, after the tune up and seaf.oam last night, IMRC bank 2 numbers are slightly different (higher, but not a wider range), still wrong... air flow is still pathetically low!!! why???
https://www.youtube.com/watch?v=6QGQSRvhl7k
 

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