rockiew55

89 Trans Am GTA 5.7 350 TPI

Howdy yall

my car is currently throwing 12 codes. it is running, at least idling i havent driven it since this started happening.

while idling seeming normal every 15-20 seconds or so it will surge for a couple seconds with rising rpms, and the return to normal for another 15-20 seconds. with scan tool plugged in, when the surging occurs the codes will change, it will always keep 8 codes right when ignition turned on, even after resetting the codes on ecm.The last 4 codes appear and disappear from scanning whenever the car surges. sometimes it will show 9 codes etc....up to 12 codes.

has anyone had this problem before?
i will soon have the alternator and battery tested. i will be attempting to check the grounds also. only thing i cant check myself unless i find a way how is checking if the ECM or PROM is bad. I will probably be sending them off to some company that can test them. anyone know a place? or maybe the voltage regulator has something to do with it also?

the codes it has are
24 Vehicle Speed sensor (vss) open or short circuit problems or park/neutral switch circuit problem
25 spark reference (24x) signal (low voltage) manifold air temp (mat) sensor or Intake air temperature (IAT) high temperature
26 Quad Driver module or quad driver no1 error
41 cam sensor failure or cylinder select error or EST electronic spark timing circuit open or shorted to ground. or ignition system fault loss of 1x reference pulse signal
43 electronic spark timing EST circuit, low voltage. or electronic spark control circuit problems
44 lean exhaust left side on dual oxygen model
45 Rich Exhaust indicated (left side on dual oxygen models)
51 computer problem faulty or prom
52 calibration package chip or ecm fault or PROM chip. or ecm system voltage high for a period of time
54 Fuel pump circuit fault or M/C mixture control solenoid fault or ECM fault/EGR solenoid #2 failure or fuel pump relay
61 oxygen sensor signal fault or port throttle or on board cruise control, or AC system problem
63 egr flow or on board cruise control sensor or map sensor or oxygen sensor

the codes that are not always on are
codes 24 25 26 45. they only appear randomly with the surging. the other 8 codes are always present.

thanks yall

Tuned Performance

iTrader: (92)

Sounds like a faulty ecm with all the bogus codes.63 & 26.
Sounds like a circuit board solder joint or crack.

Tuned Performance

iTrader: (92)

Btw your malfunction descriptions are alittle off for your application.
http://chevythunder.com/fuel%20injec...0pg%20a.htm#24
Ecm numbers followed bye superseded numbers.
1227165,16198259 or 88999194 & cardone 77-7165

rockiew55

Thanks for the reply, the descriptions of the codes i had were all just from my innova scan tool.

i wanted to order a new/used ECM from Hawks but i dont have the original service number, it looks like the sticker was ripped off by previous owners. there is plenty of other numbers on the ecm. none of them match the service number list on hawks website though. or the number you posted.

anyone know another way of getting the original service number? or a good shop that tests and repairs ECM/PROMS? Or a good phone number to call and find out vehiucle history by VIN. i tried local GM dealer and Pontiac numbers i found online, they didn't have the capability of of looking up original service number or part numbers for my car.

Tuned Performance

iTrader: (92)

I listed the service numbers above. I'd start with a ecm then if it's still doing the same thing I have gm memcals I can program to suit. You might want a different prom I've seen thouse Hypertech go bad .

rockiew55

Hey Tuned Performance still offering gm memcals? I got a new ECM and the codes are still present. I also had battery fully charged, and tested alternator. I cleaned up the ground factory ground straps, and added 3 new redundant ones.

so can i buy a memcal off you? do you sell prom chips too? or where to get one for my stock car?

89 Trans Am GTA 5.7 350 TPI

Thank you

Tuned Performance

iTrader: (92)

I'll send you a pm about what I have to offer

rockiew55

update to close this thread, if anyone runs into this problem and searches this. i figured out this 12 code problem a long time ago not to long after i posted this. my innova scan tool that came with gm adapter for obd 1 was to blame. it caused all these codes lol. It turns out it is not compatible at all. the surging idle however was the beginning of a possibly bad maf sensor, not sure on that because i got rid of the maf sensor, and replaced with a rebuilt one. so i never tried the original maf again. but the true problem was either the maf or burn off relay was failing. intermittently one or both not working even though relay tests showed they were working. after i replaced them both the codes went away and the car ran perfect. even though a couple weeks later code 36 popped back up again. still runs perfect though for now.

even though i bought a prom from tuned performance, and a new ecm. neither were probably bad, it was just the scan tool...