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post #1 of 10 (permalink) Old 02-03-2013, 06:44 PM Thread Starter
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mystery lt1, almost done

my winter project car log so far

i started by swapping the plugs out, which were no longer sparking from running so rich from PO trying to diagnose the problem. figure it's a good place to start.

yes, that's a header gasket laying there.. because i had to pull the headers to get out the plugs. from there i proceeded to yank the entire engine harness, throw the greasy burned peice of crap in my car, and drive home.

this was the worst kind of hell, even though i know my electrical. it's a lot of wires, man..

i found some serious hacking had gone on in there, the sensor ground bus was disconnected. the ecm was grounded to the sensor ground bus. easy fix! i pulled all the gm splices and soldered them up really good, just in case.

i yanked every single unnecessary connector while i was there, now it's an emissions and air conditioning free harness.

back in for test running, still needed some re-routing, but it fit pretty good, considering i wrapped it on my desk instead of in the car.. the wiring passing by the dipstick down the headers, i didnt plan for that.. i re-routed it down the firewall later.

unfortunately it still ran like crap, still wouldn't connect to the scanner, or read a bin. 'checksum error'. ecm fried, i'm guessing...

myltwon sent me an ecm pre-tuned without any codes or vats, threw it in, and it ran like a boss! ... with rapidly falling oil pressure because the oil was full of gross old foamy fuel, and it idled like shit. revved it out, a little, nothing. it went into closed loop, and the trim tables were rediculously lean. then it threw a maf code and started running worse. i shut it off.

great way to break it in, huh?

i drained it, put in some 10w40 with gm EOS and seafoam. now the pressure goes up more every time i run it.

then found no power to the maf.. trace it back under the dash, and find out; there's no pink power wire where there should be, on the chassis harness. snip..butt connector.. threw it on the injector power bus for now. no more maf code. running even better.

this silicone-free high temp 1LE intake elbow was $12, boat exhaust parts rock, in case anyone wondered how to get a cheap replacement..

i tested every single vacuum line coming from the intake except the brake booter for some reason, and they all had leaks and issues.

now it runs great, just idles kinda high, and still trims a bit lean, but that's to be expected.

it moved out of the garage under its own power, f#%kn eh! it leaked oil everywhere because the dipstick snapped in half while i was taking my headers out, but i have a lokar flexible stick waiting on my desk..

i ripped it around town, this car refuses to hook up, its sliding everywhere like a drifter.. but i soon found the brake booster was leaking.

the howling under the dash got louder. big vac leak, and it's pretty hard to stop the thing. just waiting for a new one.

but in the meantime, i shoved a ratchet extension in the brake booster; and loaded a mail tune from a similar car that someone else has.. and it runs perfectly.

drops right down to a slightly lopey 900 idle and hangs there, even from dead cold. trims in closed loop up to 3k are bang on. im scared to take it higher with no brakes.
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post #2 of 10 (permalink) Old 02-03-2013, 06:55 PM Thread Starter
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other stuff i've fixed... it's been a long road full of gremlins.. this body looks like it sat for almost a decade before the engine transplant

- fuel pump line to sender head cracked
- tank and fuel system full of gross sludge
- drivers window motor fried
- starter dead
- primary ground to engine mount weak
- battery terminals damaged
- bump stops rubbing tires....deleted..
- connected headers to stock exhaust with a bunch of 45's and clamps
- headlight switch on column broken
- map seal torn
- icm not greased
- plug wires torched on headers (need otvc soon)
- calipers seized
- p/s lines leaking
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post #3 of 10 (permalink) Old 02-04-2013, 05:20 PM
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WOW !!! You have extreme patients and sheer tenacity if nothing else. I probably would have given up before I got started. Trouble shooting electrical gremlins is bad enough without having to go behind, and figure-out someone else's electrical prowess (or lack of). I guess it should be all down hill for you from here. Good Work and Good Luck.

'97 Camaro Z-28, M6, 383, Vortech YSI w/ FMIC & Godzilla B.O.V., Water/Methanol injection, AFR 190 Heads, 236/248 Comp Cam, BBK 58mm T/B, LT-4 Intake Manifold, 60# Injectors, 24x Conversion Kit, Holley HP-EFI, LS-2 Coils, Moser 31 Spline Axle, Moser 9" Rear End
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post #4 of 10 (permalink) Old 02-27-2013, 07:57 PM
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Re: mystery lt1, almost done

No doubt an amazing feat! Good luck!

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02 Trans Am Firehawk #153
Arctic white on black leather
LS1 A4

Originally Posted by ShowNoMercy
You have a automatic, a dyno will only hurt feelings.
Go race your car
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post #5 of 10 (permalink) Old 02-28-2013, 12:24 PM
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Nice work ! Where did you git that elbow for 12 bucks ?
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post #6 of 10 (permalink) Old 02-28-2013, 12:40 PM Thread Starter
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trident rubber 90 degree 4" wet exhaust elbow, it's EPDM rubber. have to talk to a local boating store.
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post #7 of 10 (permalink) Old 03-04-2013, 11:46 PM
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Nice job

93 Trans Am lt1, 94 Caddy StS 4.6 Northstar, 84 Buick Le Sabre Estate Wagon 5.0
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post #8 of 10 (permalink) Old 03-05-2013, 04:54 PM Thread Starter
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pulled some voodoo last night

this thing had a lot of unburned fuel run through it and oil pressure wasn't too happy

i de-sluged by getting it nice and hot and running a few quarts of ATF through it for a half hour

filter came out full of brown sludge, idle oil pressure doubled and it touches the top of the gauge at WOT now

dont try this at home
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post #9 of 10 (permalink) Old 03-05-2013, 06:52 PM
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Looking good!!!! i HATE electrical work.. i'm dreading when i wire up a dual battery, lots of lights and a winch on my fj cruiser for off roading...

Former owner of one of the most powerful firehawks known to man.. 95/584 ..she will be missed and not forgotten.. May her new owner treat her well and not wrap her around a tree
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post #10 of 10 (permalink) Old 03-07-2013, 02:13 PM Thread Starter
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