nbressette

I bought this ECU which comes with the ACFZ PROM.

https://www.ebay.com/itm/1987-1988-M...53.m2749.l2649

My research seems to show the ACFZ came out of the 87-88 Monte Carlo SS with an auto L69.

Does anyone know if this is a direct swap into my 85 z28 with a LG4 and a 700r4? I don't have AC which I think helps.

My goal was to get to the newer ECU and a PROM with a bit better spark map. I'll plug it in when I get it but I'm curious if anyone knows how (un)successful I'll be

ken5

I just purchased a similar ECM out of a 1987 Monte Carlo SS. 1228079 -ACFZ-MV9-L69-GT4. I just hit the jackpot, too! Anyways I was wondering how did everything go after you installed this ECM. What was noticeable and what problems if any? Please update soon.

nbressette

Install was silly easy, plug and play. I noticed a smoother idle and what seems to be smoother timing transitions under normal / fast driving. Overall its one of the easiest and best mods I did. I think the newer ECUs just have a better processor which allows the computer to handle timing changes / carb mixture adjustment faster and smoother.

ken5

Thankyou for the quick response. I asked because I have a 1992 RS v8 TBI that I swapped to a 1989 CCC Rochester Q- Jet Chevy L31 setup. After all the appropriate rewiring using a 1228330 ADAY out of a 1989 Brougham Cadillac. It ran flawlessly without losing 4th gear overdrive for about a yr. Well during this fall of 2018 I kept getting code #34 (Low Map). After I changed Map Sensor and erased the code by unplugging the battery. It would keep coming back. So, I connected my laptop running Tuner Pro RT & APU1 and an ALDL OBD1 Switchable Cable Connector from 1234 Electronics. I could actually see what the ecm was seeing. Next step was to measure ECM signal and it was 0.02 with key on and engine off and 4.93 with key on and engine running. The odd thing was the engine started being hard to start and idle erratic as if it had a vacuum leak. I went and rechecked everything to no avail and decided to get a 1986 Chevy Caprice ECM out of junkyard. Started and runs fine with no codes. So I went to test drive and immediately a knock sensor, no dist signal, and egr code appeared. The car was in fact a flood victem,I assumed by the interior seats and carpets. Anyways, I noticed that the code #34 was non-existant. So I logically leaned towards the ECM needed to be replaced. Replaced it with a BLUE STREAK 1228079 from autozone that was giving me the same latter 3 codes. Returned it for a full refund after showing Autozone manager diagnostic screen shot from Tuner Pro Rt. Bought 1228079 ACFW off EBay with no refund. Got the same 3 codes. Now pissed...I called an Automotive Electric Diagnostic Shop in Hendersonville, Tn. He recommended me to a salvage yard where he (the owner) had recently junked his wrecked vehicle ...wait for it ...."1987 Monte Carlo SS". Called the salvage yard and the 3rd Gen Jeti Lords were with me. The guy starts explaining to me about the car coming in wrecked, unaware that the original owner told me his son wrecked it while hot ******* it and where to find it. Unfortunately the car had been crushed but he still had the ECM on the shelf. So I jumped in my 1997 GMC Z71 and flew less than...wait for it...." 10 miles from my house" to retrieve it for $54.00 after taxes with dust included free of charge. I haven't installed it yet, but I might have to switch back to a HEI Dist due to no dist signal if it reappears. But pertaining to my question. I was just curious to the nut chattering excitement of this particular 1228079 ACFZ ECM. It isn't everyday you find a 3.73 gearing 1228079 ECM. I will update when the cold weather clears up here in TN. Thank-you

Map Sensor Data

Code 34

ken5

Update 2/16/2021:
Okay the problem was the MAP sensor was bad pertaining to the 1228330 ADAY out of a 1989 Brougham Cadillac and now she runs fine, but I do have a bad spark plug or wire. I have noticed that the Tach will bounce when idling in closed loop around 650rpms. So currently she is: Set distributor at 10* BTDC and set idle to 750rpms in drive. Also, I had to purchase an "Alldata" 3210 to set the E4ME. The dwell is at 28-32. The APT Valve Screw is set at 4 turns out from bottom. The Stop Rich Limit / Lean Mixture Screw is set at 3 1/2 turns out from bottom. TPS is set to 0.48 and Both Fuel mixture screws in front are set to 2 1/8 turns out from bottom. Now it took me some time to figure this thing out as well. Knock was out the roof one time at 255 knocks because my bottom header pipe bolts would come loose at the collector pipe. So I installed some junkyard 1986 Chevy S-10 exhaust springs on the bolts to keep them tight because of the vibration. I had to install a radiator hose spring in the bottom radiator hose to keep her from overheating due to the bottom hose collapsing when engine was trying to suck in some water. Now, she never gets above 205*f in the city traffic and with one electric fan set to come on at 185*f and a 180*f thermostat, with two holes drilled in the sides. I also believe the knock was high due to the fact that I have an LT1 SS Camshaft and I was using cheap 87 unleaded. I noticed that when I used Premium or Non-Ethanol Gas my knocks would drop down between 1-3 knocks.

ken5

Ps...All of the ECM's I purchased are fine. The other codes were due to the fact that Chevy rewired there G & H Vin cars different than the Vin Y cars. After rewiring the Monte Carlo SS ECM's the car would run flawlessly, but I would get a knock light when I punched it or going up a steep TN country hill. It became annoying. So I rewire the 1988 Cadillac Brougham ECM back in and that's were she's sits now. I have included all my settings because it took me years to find the right one. I just figured I would post my experience and help get somebody on the road. If you go the same route that I went you will notice. The E4ME will need to be rebuilt. The settings will need to be reset to your project. My son's 1984 C10 305 Original Q-Jet mixture screws were set at 1 1/8 turns out from bottom. I actually cut and removed his plugs, because I could not find the Factory settings on this carbs or have the tools. I will post the tools I fabricated and purchased to rebuild and setup these carbs. I will post back in a few days, because it's freezing (inclement weather) outside and the house is so much more pleasant at this particular time.