93 z28, auto, new/rebuilt motor, patc 700r4/4l60 level 3 trany, 2000 5x converter, le2 heads, le intake, le cam 58mm tb, gm opti, lt headers. put the new motor in, had a hard time getting it to run from the get go but after setting the fuel pressure as low as possible got it to run fare and idle at 1k, trany would slip at shifts and was not engaging at low rpms. in trying to get the idle to work at normal fuel pressure i took out the pcmforless tune chip to see if there was an issue with it and with no change switched it back, well heres were the problem gets worse, i put the dang thing in upside down and it screwed the pooch, wouldnt run right and was throwing a 51 code of coarse so i then found the upside down chip and took it out, put the memcal in and it would not run right at all. i sent the ecu and memcal in and they check our to be good. got it back and now using the paper clip way i get the 12 flash but no codes. with my innova scanner im getting a prom error code and a rich right 02 code. also some ac codes but pretty sure there cause i havent had the system recharged yet. so far ive had the ecu and prom checked both ok, found a problem with the evap and replaced bad parts, set and tested the tps, 2 sets of new plugs one set fouled. the car will not idle low way rich wants to idle at 2k and runs good from there up. ok on to the tranny, it didnt seem to work right so i took it out and sent it back to patc to be checked and put the stock trany back in with a stock converter. once i got the stock trany in i thought for sure the patc trany had problems. stock trany will not disengage or seemed that way cause im idling at 2k so i change the 58mm tb with the 52mm i have and get the idle down to 1000 when warm but wont idle for first couple minutes after startup. now the trany still seems like its locking at low rpms cause it almost kills the motor (probly because im rich) even at 1000 and the rpms will go down to 7 to 800 but i have to hold the brakes stiff on to stop the car, still slips really bad at shifts, seems like the shifts are harder at low rpms, so any ideas were to look? most dealers wont work on modded cars so im thinking about callin around monday to see if i can find a well recommended shop to do some diagnosis on her but im thinkin they will charge me to tell me what i already know.

 

Doesn't sound right. How did you interface the electronic 4L60E to the 93 ECM, which does not control the tranny? 93 has an "Engine Control Module" (ECM), not a "Powertrain Control Module" (PCM)..... or are those just typos?

 

its a typo. should say 4l60, my bad. any ideas, im gona test the grounds to the ecu just in case theres something there and then unplug the trany tcc plug and see what that does. when i got the news the trany was good the guy at patc told me to try that to make sure its not the trany. the air fuel being way rich has got me stumped.

 

I had to take our '95 Z28 in for work because the A/C compressor wasn't engaging at all.

The mechanic discovered code 51, PROM error, coming up. When the mechanic cleared the code, the compressor started working again.

Your story is like a big deja vu to me. We've owned this car since '95, back when my parents were still married. Unknown to any of us, my dad put a hyperchip in the car for a period of time and never told any of us, and guess what? When he slipped up and told us that, we were all livid! Let me just say this... if our car starts idling at 2000 RPM AGAIN, like it did 10 years ago... I am going to be sooooo pissed!

I have no idea what a hyperchip even is, whether he put it in upside down, or anything. The electrical stuff like that has always confused me.

 

I answered your "chip" question in the post on the "General 67-02 F-Body Tech" forum. There is no removable chip on your 95. All your father could have done is add a Hypertech "module" that inserts between the PCM and one of the harness connectors.

 

My sister texted my dad because she was pissed about this problem, and this is what he said:

""The ECM chip that I swapped years ago (but returned back to stock few months later) has nothing to do with the old car issues you are dealing with today."

He's done professional instrument control crap in the past, so anything is possible with him. Part of his job has always involved electronics, wiring, soldering, etc. When you say "chip" Injuneer, are you referring to the ECM chip?

Can you briefly tell me the difference between ecm, ecu, and pcm?