GaryDoug

This app doesn't report History trouble codes, only Active ones. I never saw a condition when my pcm ever showed any difference in the two types. Maybe some day...

threehourshower

the AIR plumbing is still there, just unplugged. its been bad since i got the car so i just never replaced it.

Anyway, i guess i should tell you guys why i feel so lost here.. last august i had a shop swap my LT1 because of a knock and tick issue. I found a good deal too, the shop next to my old job said theyd charge me 1200 total, parts and labor. A deal it was, and a 1200 engine swap was definitely what they delivered. oil pressure sensor doesnt read on the dash, nor does the temp. had a NIGHTMARE of an issue last summer when the fans wouldnt turn on at all. that turned out to be a wiring issue. other things i noted that have since been corrected include a forsaken vacuum line (the one that runs with fuel send/receive lines), the vacuum controlling the A/C vents, the serp belt ate away at a wire connected to the positive battery terminal, the starter sparks because its not shimmed properly (id fix that myself but i ALWAYS break the damn nose cone that makes shimming so hard in the first place)

ill be honest here; as i am asking you folks for advice, I have the car listed for sale. Im not sure i have the finances to cover all the necessary parts (and labor if its out of my league but ill usually atempt anything at least once). I love my f body but she doesnt love me back.. if i can fix the issues i MIGHT hold onto the car but ive grown weary from the lack of reliability. Thoughts?

Injuneer

Doesn't sound like anything major. You need to spend some time on Shoebox's site, if you haven't already:

http://shbox.com/1/4th_gen_tech1.html

Oil pressure sensor is on the top/back of the block. Single wire. If the wire is off the sensor, gauge will read 80psi.

http://shbox.com/1/oil_pressure_sensor.jpg

Coolant temp sensor for gauge is on the driver's side head, between #1 and #3 plug. Single wire. If wire is off sensor, will read at bottom end of scale.

http://shbox.com/1/temp_sensor2.jpg

See wiring harness showing the two connectors mentioned above.

http://shbox.com/1/harness.htm

What specifically is wrong with the EVAP purge line in the fuel line bundle?

Vacuum source, and vacuum check valve for HVAC - attaches to vacuum port right above fuel pressure regulator vacuum source:

http://shbox.com/1/fp_reg.jpg

http://shbox.com/1/vac_check_valve.jpg

threehourshower

oil pressure gauge is absolutely floored, no movement at all. and the temp is through the roof on cold start both single wires?? are you thinking what im thinking?

anyway ive already replaced and repaired the necessary vacuum connections. What i really need to do is get the three delete plates. whats funny is the evap purge line is run over a foreign frame over the intake manifold due to foreign vehicle donor for the swap... as far as shoebox's site goes, well im pretty sure im there more often than here. Needless to say great job, praise be to he that enableth the would-be mechanic.

But the main concern here is the incorrect o2 sensor readings burning up twice my gas and my driveline vibration. The first HAS to be a pre-sensor leak. i have had exhaust leaks on other vehicles, but never any that caused me problems like this. ill hit those bolts with pb blaster right away. thank god for making your own schedule. if my leak is not the manifold gasket then ill probably be letting the next owner have fun with that. and those bolts had better not give me much trouble.

for the driveline vibration, ive read that i could take awhile to diagnose actually. What i know is that it is not congruent with RPM. tells me to look from tranny back. Im starting with the mounts but if they appear to be fine i will rotate the driveshaft 180 degrees assuming its easier than changing plugs and wires with stock manifolds. I read that that sometimes the steel driveshafts can become unbalanced and potentially be cured by the rotation. perhaps i should even look for an aluminum replacement. Somebody else i described it to said he was sure it was my rear differential. To that i say...no. simply out of my element and definitely not worth my time to learn. i have more money to make working my job than working on the car (which has come out on top for a few weeks now). Thoughts?

Injuneer you have been instrumental in helping me work on my own vehicle this past year, especially with this thread, taking the time to read my data logs and translate car to human for me. anybody that doesnt seriously consider your advise is a damn idiot. plainly stated. you and shoebox are the heart of the fourth gen community here, who knows what kinds of exchanges would be left uncorrected?

threehourshower

Ok guys, here is an update for you. Ive been swamped with work but i managed to change the manifold gaskets and plug another leak i found in the exhaust before the o2 sensors. its running much better, but still it feels a bit off.

Here is another scan table i managed to run this morning. It starts off with a stroll around the block, and idle for a few minutes, and then a liberal drive through the main streets. I guess im wondering if I should still be looking for leaks?

May 14th

threehourshower

My high speed vibration turned out to be bad u joints on my driveshaft, so i had it replaced and so far all seems well with the drivetrain.

Now though, my exhaust leak has returned. It wasnt present yesterday morning after i thought i fixed the leak, so i went ahead and took it to the shop for the driveshaft. after leaving though, im having an exhaust leak again. It is definitely causing me a performance issue. Ive changed the manifold gaskets and JB welded a tiny pinhole i discovered in the passenger side AIR valve elbow (both sides are blocked after the valve. Now the leak seems to be coming from the flange just below the o2 sensor. Can it still cause a power loss issue like this? I dont care about the noise it makes, but it doesnt feel right AT ALL. I think ill look at changing these flange gaskets tomorrow (unless i can manage to just do one without dropping the whole thing) but im slamming my head against the wall here. my money is disappearing and all the problems i solve just seem to create or shed light on new ones. Im trying to sell the car so i just need it running smoothly. No SES anymore by the way. Let me know what yall think, because i might just drop my asking price to 2500 and call it a day. This is becoming so frustrating, wish I knew somebody around me thats good with f bodies

BONUS: Im taking the car back to the shop tomorrow. The mechanic that did my u joints left a jobsite flashlight (the kind that uses drill batteries) somewhere underneath and when i got home i found it lodged between the exhaust pipe and its shielding next to the rear diff. no telling exactly what happened down there but maybe the mechanic owes me some new stuff..

Injuneer

I'm way behind in looking at data logs... maybe get a chance over the weekend.

threehourshower

Ok Fred, take your time. Im grateful just to have had you reply in the first place.. anyway i think ive pretty much got a handle on the issues from this post, having replaced the u joints to solve my vibration problem and chasing down exhaust leaks for the performance.. i know i still have a leak but its not nearly as bad.. anyway i have to start a new thread, potentially my last. more info there.