Ive been trying to figure out what my cars thinking, one day it runs great, the next day it runs rich, idles high, and runs hot, HOTT, likle pegs out the temp gauge!!! the gauge goes from 180-260 in no time!

after a 30 minute drive, i pulled up in the shop & heres what my scantool had to say about my 85 tpi camaro at idle:

coolant 164 f
egr duty 0%
rpms 1050, was 750, idled up when i plugged in scanner!
IAC 45
inj pw 0!
ECM CLSD loop
MAF 2140 grams/sec
mat 114 f
o2s(MV) 400
o2s crsscnts 140
tps .58

setting codes: 33, 42, 43
also:
i was driving last week with my cutout open, and suddenly the car jolted, and the code for esc set the ses light on

Im still new to reading this stuff, but id like to know what the hell it all means
before something comes apart~!! thanx!

 

Have you tried a known good ECM/PROM to see if these problems reoccur?If not ,I would try to locate a set.If it doesnt help then at least you have eliminated it.Then you would start checking out each code number.

 

the ecm is a new gm 870, and the chip is the stock 85 5.7 corvette prom

i need to know what this stuff means so i can understand what needs to be changed to tune it correctly!

I have a 730 ecm that im eventually gonna swap in,but that maybe a while, im trying to find diagrams for the ecms pinouts, so i an repin my 870~730

 

coolant 164 f
egr duty 0%
rpms 1050, was 750, idled up when i plugged in scanner!
IAC 45
inj pw 0!
ECM CLSD loop
MAF 2140 grams/sec
mat 114 f
o2s(MV) 400
o2s crsscnts 140
tps .58

setting codes: 33, 42, 43
From what these say..I would say your MAF is kinda high..have you checked it?..Back in the day..it was an easy check..lightly tap on it while its running and the idle would become irractic.This reading might be a default value not true sensor reading.If your scanner has Air Flow grams/sec compare it to the MAF value should be the same,if it isnt I would be looking into swapping a known good MAF sensor.
The 730 is a speed density set- up and that would eliminate that MAF sensor,you might want to look for a manual or schematic for a 90 camaro cause I have that 730 in my ride.I think the v8 and v6 of that era had that 730.

 

well the maf is brand new, a month after the 350/zz4 build the maf crapped on me, a reman was $279 at oriely, at GM it woulda been $515
good ole robert bosch design! aka expensive german parts!

ive tried tapping on the maf, it makes no difference, but if i unplug the maf, the car wont even start!!

i just don want to swap the 730 ecm in, and something not work right! then al of a sudden, i have a $5000 paperweight!

i would just swap in a 650 holley and intake,but i like mileage!

i just need to find the pinouts!

everyone tried to charge me $200 a pop for a shop manual but im not even sure the ecm pinouts are included in those, and id need the 85 and 92 manuals($400) i cant see putting that much into books i'll never use again!

the davisz28 guy has done the swap but he went from 870~164 and then from 165~730, im gonna be skipping over the 165 and straight to 730, but im limited on where to get diagrams, i would just yank a complete 730 harness,but I have the Only TPI car within 100 miles that i know of! abd the salvage yards all tell me good luck finding a complete harness!

If i could get the ecm pinouts and underhood sesor schematics for an 85 tpi 305 and a 92 tpi 350 i could swap some wires, install the map, and jumper the esc and that'd be that!

i have already bought a new 5.7 chip, aujp, and burnt a chip with the increased bore, and 24# injectors, that should at least get the car started and running!

 

They dont have any junkyards in Texarkana?..or is that the nearest place you spoke of?..I have to agree with you..you need some schematics.I dont have any on hand other then a 91-92 and I dont know how different it is to the 85.The only thing I can do for you,is I can make a note and see if there is something at work on the 85 ECM schematic.I am on vacation and dont plan on going back till Thurs.so I will see what it has and let you know.
The price of those manuals is blackmail..not a price!!!..I dont have a scanner if I do get something... if you had a fax machine I could get them to you or just mail them...but let me see what I can dig up first.I'll email you probably sometime Thursday night(AZ Time).

 

My 85 Z28 and Changing a '165 ECM to a '730

I was surfin and came across this web site ,might want to check it out..check it out and tell me if it helps any?...

It has the wiring schematic for the ECM your looking for?

 

i have visited that page, my problem is, i am going directly from 870~730

davis went from 870~165~730

i need to figure out how to do the swap without the relays and stuff that 165 requires!

i figure, if i have both complete pinout schematics of the 85 tpi and the 92 tpi, the swap should be gravy!

i just want to make sure i have good reliable diagrams, otherwise, i could short the ecm!

 

Okay,I did a research on what your trying to tackle and the 85's are kinda on their own.The schematic for the 85 TPI is the one you need.Cause I already have the 92 TPI.I understand the 85 has a mass air flow module and the ECM only uses 2 ECM connectors rather then the 92 or 730 will use three connectors.Once I find something I'll post it..otherwise I think my best bet is at work.

Whats the difference of that 86 schematic on the web page then a 85?

 

the 85 has a piggyback maf module on the ecm, and the 86 doesnt. it has some relays under the hood instead. a friend of mine told me to get ahold of somebody that has alldata, and that most shops carry something similiar.
im sure someone else out there has done the exact same thing,but they havent posted very much info on the swap!

thanks for looking into it!

if you find something at work thursday, let me know!

 

Have you looked at the Tech Articles recently ??....they have the 85 wiring schematics posted?..didnt see them there before.

 

yeah,but they dont have the ecm pinouts!
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btw, did you find anything at work?