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BUILD The millenium 3800 turbobird


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RdRnnR

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So, pulled the vband loose cuz I thought I heard somethin on the passenger side and I guess when I tightened driver side it must've pulled through the clamp because it was scooted over a ways and definitely leaking. Couldn't hear it with downpipe directly underneath, or at least distinguish the two.

To remedy this I'm tryin to smash an old donut off one of the bastard ramhorn manifolds from my camaro out back between the bolt together ball end of this crap ebay kit in attempt to keep it all tight and push it back over where it needs to be.

No wonder so many of the cars with these kits never see past 8 or 10 pounds and why there's always people sayin they've cracked these manifolds. I for one feel lucky it was the clamp that slipped and that I'm not over here with the original manifolds off this one bending up junk exhaust from my pile out back to just make a new set of headers. But I'm about to that point. Literally the only good thing about that whole ass kit is the flanges on the headers and I'd put money those aren't flat either. Stupid 2.25 v band on it to boot so go figure instead of just throwin a good 2.5 on I had to smash it back to shape in the vise and hopin it works.

I'm not super optimistic tho I don't really see any way that could be throwin the sensor so lean when it's in the crossover right past the stupid ball joint. But I'm gonna guess that was probably leakin too.

It'd make sense tho. Ya know if they didn't fit my camaro right when I was having the exact same issues. And that I tore that car apart to build this one for the same thing and it turns out to be I carried the one thing that's a problem with me....only other things could be bov leakin vac possibly but thats easy enough to check and shoulda shown with the boost test.

Also changed flow rate on my injectors to 60 across the board but left the offsets. Loaded stock maf and map tables. And she is literally perfect on ve. 14.7 with a +-1 difference on wideband. 19.6 to 20.1 inches of vacuum. 18 degrees of timing. Barely fluctuation with brake pedal and chop the throttle all you want it won't won't comin back to idle. So smooth and quiet you can't even tell its on the downpipe. Command cl....and trims are buried positive, drowning it and in turn its tryin to bump timing to keep itself alive.

But how tf is my wideband accurate if there's big enough leaks to dick with my o2s that bad. Cuz I've seen some bad leaks in ls's not do this to trims. Or at least the sensors would still read.... Snapchat-434577608.jpg
 

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I feel for you dude. I guess I should probably mention that I have a full dxf of our exhaust flange for my 30 degree exit header flange.

I never really thought about changing it to just do regular flat flanges... cuz I hate straight exit pipes on our exhaust ports
 
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Im just not real sure what to do if this doesn't cure it. Fail the trims and try and maf only it with the wideband? Do I dare try and go off the ve table and just rape the shit out of the pe and hope I can keep it roped in that way? At least for now and use to the other car to build a set of new Manis with the good stock manifolds while the 3.8s still in it? Ugh o_O
 
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Definitely got the leaks calmed down alot after cutting a donut in half to fit and jamming some silicon in the joints but it could still use a little help.

But now I finally get o2 both banks no activity so I must've made some sort of impact....somehow. but I think that's because I did some switching back and forth on wires to make sure they were right and pry smoked the sensor maybe idk. Gonna recheck my wiring maybe try couple different o2s and see what happens. If not I'm tired of screwin with it for now and I'll just disable closed loop and try and work it out off my wideband.

Unless, and I know it's probably stupid but beings the wideband has a narrow output signal can I use that as signal to the pcm somehow? Idk why I care so much about the trims I just wanna make sure I can tune it out with the maf and I'm not gonna risk it randomly goin lean and all this goin to hell on me
 

Turbocharged400sbc

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Put a nearly dead double-a or Triple-A battery across the signal Leeds and see if you get one volt (check the battery with dvom....and note voltage) on the pcm o2 reading
 
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Put a nearly dead double-a or Triple-A battery across the signal Leeds and see if you get one volt (check the battery with dvom....and note voltage) on the pcm o2 reading
Damn that's a good idea.

I mean two same color wires are 5v signal and the other 2 power and ground for the heater circuit ya? Should it matter if either of those gets switch as long as they're on the right side of it?
 

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I don't think it would matter but I would not switch the signal return ground with the heater ground on the oxygen sensor circuit.
Power for the oxygen sensor will be the pink wire the purple wire should be the signal wire and then there will be two black wires for the signal return and the heater ground
 

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I don't think it would matter but I would not switch the signal return ground with the heater ground on the oxygen sensor circuit.
Power for the oxygen sensor will be the pink wire the purple wire should be the signal wire and then there will be two black wires for the signal return and the heater ground
I'm so glad you're back :fy:
 

Turbocharged400sbc

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Yeah the signal return ground will actually be Tan in the engine harness and it will go to the blue pcm c1 connector pin 29. The downstream catalyst signal return will be pin no 28.
23-27 are unused on the front wheel drive cars but if I'm not mistaken I believe they are for the bank 2 Upstream sensor for the F bodies.

Pin 10 and pin 11 on the clear connector are the upstream and downstream signal pens

Black wires on the engine side harness are for the heater ground.


The downstream sensor on our fwd cars use the white tracer. Same colors.
 
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Tan purple black and pink drivers has white lines in the signal. Tan and purple both being 5v pink at 12 and ground is well, ground so im assuming that's the heater ground.

Sensors white white gray black.

I think I've had signal and heater wires mixed up thinkin power and ground would go to the two different colored wires 😕

I'm so glad you're back :fy:
He was gone?
 

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He's back, that's all that matters.
 
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At this point I'm convinced at least half of the world's 3800 knowledge goes wherever he does. And it's not the easy half :bowdown:
 
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^^^If this happens and I don't see it somebody tag me in it. I'm not missin out on pandoras box :ROFLMAO:
 
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Yep had wires switched go figure, toasted one of the o2s for sure but I swapped it out and I finally got fuel trims on its own at least. For whatever reason they're still reading lean as hell tho. And I don't understand how my widebands readin down to high 9s when it goes into cl. Might see if I can tweak flow rates or somethin again but it's hard to think that'll help when it's definitely pigging it down and makin it run like ass.

20210519_233440.jpg
 
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Kinda thinkin I fried the o2 circuit on this pcm or the butt connectors I put in to get em to work are where the problem is but I'm entirely convinced the problems here at this point. Voltages are just dropped to .000 and twitch to .004 on both banks once in a while in hpt but at sensor its more like bank two is 1.28 and bank one is .446 which is probably where it should be.

Had 80 in the injector flow to lean it out and if I disable the long terms it'll sit at bout 14.3 but after sittin herself yfor a while lettin it run it just up and died. Like abruptly like I turned the switch backwards. Fired right back up without hesitation tho with nothin but the oil change light on but that's what makes me wonder about the pcm now. Good thing I've got a spare or two but it's hard to believe it's doin this and not throwin any codes when I've got em set to throw a light on first error.

Pry toss a box in it and pickup some new o2s while I'm in town tomorrow and figure out why my wideband isn't pickin up through serial or my pro link while I'm at it. We gettin there tho. I don't wanna jinx it again but I'd love to finally get a pass out of her at test and tune this weekend Snapchat-684181183.jpg
 
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I give on the o2s for now. Commanded it open got my wideband to read at least somewhat and brought her to town to pick up kids on their last day of school. Hopefully if I keep it out of boost it'll stay together at least to get fuel in check for now and get back home :ROFLMAO: 20210520_123412.jpg
 
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Ok. So. The longer story. Changed the pcm out this morning with my other 7440 which happened to be the original from this car. Wouldn't unlock through the original since I had the 99 file unlocked from screwin around with the catfish 🙄

Got out dhp and tried my ass off for a while to get it to work to try and change vins and save myself a 100 bucks and the damn thing won't register so it's just a paperweight at the moment but whatever.

Went through and rewrote the entire file for this car. The entire thing. Still no o2s and the same thing so I just failed closed loop altogether.

Wideband wouldn't read through serial or through hpt aem wideband logic so now im logging the 5v red analog wire on my prolink and transformed it to aem afr values. Seems to be pretty close if not on but I haven't really gone through the scan yet. Fueling seems to be holding pretty well but I have pe set to come in at 10% and 11.0 just to play it safe. Stayed out of boost for the most part and haven't gone over the scan yet but on the way home my daughter said she saw 6 or 7 degrees of kr so ill look at it shortly before swimming lessons maybe try and knock that out and get another scan on the way there and back.

No leaks under it! I really thought I'd have issues but apparently the spots in the shop are from the coolant overflow tank (which I've got another good one anyway) and drippin oil off from before.

This thing really runs amazing in open loop. No surge no stutter no stallin spittin or nothin and the trans feels great in it too. Hopefully a little tuning and we got us a race car finally!
 
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Ok so im pullin timing like crazy down to 0 right where it'd start makin power really feathering this thing and it's just piggin it's happy lil stinky oil smellin ass through town and I'm over here thinkin I've watched this thing dip to 9s and I've got alot of fueling work left to do and maybe some rich knock or somethins catastrophic the way its actin but it never really acts up other than obvious overfueling and the power issues to go along with it. That being said I haven't had it back in to boost yet at all but this thing feels like it wants to just rip.

But then I sit here for a bit with the kids and then walk outside and start checkin for leaks again and it hits me. Downpipe is dumpin right into the bottom of the floor on the passenger side by the knock sensor. No wonder it was so hot in the car and it's gotta be dingin that sensor like crazy under load I'd imagine. I probably better stick a pipe on this thing today before my luck goes bad again
 
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Good I'm gonna need it :ROFLMAO: glad I had the windows down thanks to no ac but that shiny turbo sounds every bit as good as it looks even out of boost
 
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Dumpstered up some junk out of my pile to make the angle back and get that downpipe out of there. Its like 2.25 I cut off the old Flowmaster from my camaro but it'll work til I cut the 2.5 off the back of my truck and make this all nice and flowin good. I really hope this is all that kr is and I can get it stuffed in here and take a couple cruises tonight and get it roped in well enough to hit the track tomorrow Screenshot_20210521-194448_Gallery.jpg
 

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