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I have 99 regal sc 3.8L I have a 3.8L motor anc transmission out of 01 regal. They say it can't be done via chevrolet and junk yard. I have both wiring harnesses and computers. I have both bcms too. The bcm are wired differnt. The computer wiring harnesses interchange. I have already put in the 01 motor. The 99 computer will crank the 01 motor but no start. the 01 computer is not cranking the motor, the security light is on with the 01 computer and has the bcm locked the ecm out . The 99 harness will not interchange due to injector connectors are different. I like you sd like a good challenge. But I will say this, No I yell this. Help please. I live on a limited income due to stroke in 2011. I could really use some help please. Thanks and God bless.
I guess that no one has any ideas. I have both ecm's. Which one should I flash? 1. the 99 gsx sc ecm to 99 na engine which came with the car? 2. the 01 ecm which is the donor car where I got the engine that I put into my 99? 3. Pull the bcm and dash wiring from 01 donor car and install it into the 99 gsx?. Number 3 is a lot of work. lol but I cannot just change the bcm because the wiring is totally different on the two cars. Today I rechecked everything. The 01 ecm that came with donor engine/tranny combo wakes up the ecm but will not send the signal to the crank wire( yellow=black ). I have fire but no pulse on the injectors. The 99 ecm will crank the engine with spark and fuel injector pulse. I am thinking that it is flooding the na engine from the donor 01 regal. Any ideas?
To be more clear I have 99 buick regal gsx 3.8 sc. I bought a 01 buick regal Ls 3.8 na car for a donor for my 99. I have taken out both motors and trannys. I installed the 01 3.8 na into the 99 gsx. Now I am trying to make the 99 gsx power up and run an 01 engine. I thought it would be easier than it has been. I have been tinkering for 3 days trying to make the 01 engine run in a 99 body.
If it were me, I would use the 99 fuel rail if the injectors fit the intake. If not, use 01 fuel rail and swap fuel injector connector to match 99 harness.
.I have 2 cars 1. 1999 buick regal gsx 3.8L supercharged. I had the tranny overhauled 30k ago. It is out again. I have bought a donor car for my 99. 2. 2001 buick regal Ls 3.8 naturally aspirated. I took the motor, tranny wiring harness ecm out of the 2001 and put it into the 99. I took the cradle wiring engine wiring harness and computer out of the 2001 and kept it with the engine, tranny combo. The computers are identical on the pin out. The 1999 ecm will crank the 2001 engine. The ecm sends spark and fuel pulse to engine but will not fire the engine. I think it is flooding the 01 engine. The ecm from 2001 sends the wake up signal to ecm but will not send the signal to crank the engine on the yellow black wire due to security light on. The 1999 ecm has no security light so it will crank the engine. So it goes back to an issue with the bcm on the 01 ecm. I have no check engine light on. I do not have a scanner just test light and ohm meter. The 99 ecm recieves wake up signal to ecm and sends crank signal to crank relay and it cranks the 01 engine. The 99 ecm will tell 01 engine to ignite spark plugs and sends a fuel injector pulse. But floods the engine. The 01 ecm receives wake up signal to the ecm but will not send crank signal to crank relay because the ecm is not recognized by the 99 body control module bcm and sets off the security in the 99. I do not have a scanner.
Last edit: 8 years 5 months ago by jdrcop1984. Reason: wrong thought process
They are likely larger injectors for the super charged engine you will definitely need to match the donor engine with the donor ecu for engine controls can you swap harness that goes to doner engine with it?
After that we will likely have to change pins for some wires that stay with the vehicle at the ecu we will need full diagrams for the both ecu to compare pin functions I can supply them if Tyler doesn't beat me to it.. but it will be a day or 2 before I get to that computer with diagrams
Is this the chip key? The security issue will need resolved maybe swapping the ignition from the other car will fix it I believe security takes place in ecu not bcm on this car
The pulse time is controlled by the engine essentially controlling the fuel but here's where it gets tricky a bigger injector nozzle sprays more fuel so the ecu has to lengthen the pulse time. in open fuel loop it will run rich and fuel trims will be way negative as ecu is cutting fuel
According to this diagram the 99 ecu sends the crank signal on pin 23 c2 and gets starter enable on 76 c2 . The 01 is opposite of that can you verify color codes to be sure this isn't a typo on Mitchell? I find it very strange to switch colors and functions ....
update: My car lives again. I hired a local mechanic friend with scanner. He done scans with both computers in the car. He said 99 sc ecm should start the car but no fuel pulse at crank. So we shot minimal ether to it as he cranked it and it ran. I drove it around town an it did okay. But would occasionally would not start. A little ether did wonders. Then this eve I drove it 6 miles out of town and the on board display read out showed it was getting shitty gas mileage. When I was getting off the highway to turn around it died and restarted and died then surged a few times and ran again. I still have no cruise control, battery light is on but It is charging, the check engine light is on, and the trac off light is on. So I still have issues, probably in wiring. Any help? I am still leaning towards pulling dash wiring harness with bcm and installing it in my car. Anyone want to help? Free wiring experience. Also I might add I was talking to mechanic that reflashes ecm's. Yesterday it was 150 dollars, today I talked again to him before I had the car running and he made a phone call to people that has flash contract with and they said had to flash bcm too. The total would be 250 and no guarantee because The 99 bcm is not compatable with 01 ecm's. Wow. It is not supposed to work. In fact the 99 sc ecm is not supposed to run the 01 na engine. But it does. One of the codes I noticed today was no boost signal detected. But fuel trim was good at idle. In fact the mechanic said it was on the lean side. Any thoughts or ideas would be appreciated. Thanks all.
okay I slept on this. Options.....If I keep the 99 ecm.....I need to fix the check engine light. I bet it throwed another no signal from the boost on non existence boost from the sc. I need to find the two wires from that circuit and determine the reading whether it needs to show voltage or resistance and wire in a resistor or whatever that would trick the ecm that the sc is still there and make it think there is zero boost all the time. I do know where the wires and sensor was on the 99 harness. I remember seeing the sensor. But I still have the crank no start issue to fix too. And lastly the battery red light on the dash as well. Also I would still like to get the 01 ecm firing this engine as i am sure that the fuel mileage would be greatly enhanced. It showed at 65 mph last night It was getting around 20 mpg. My sc engine would have been getting 26 or 27 mpg. Also the cruise control is not working as in it is not showing that it is even turning on via green cruise light on dash coming on. I am thinking that the no tcs light is causing this as well. Ben I appreciate your thoughts and input on this. Thanks again.
I'm not sure if that'll be the only problem you'll run into with the 01 ECM you'll have to try it and report back the symptoms so I can look at other sections of wiring
Update......I had to remove dash wiring and bcm from the donor 01 Regal. I got it installed after I changed lock cylinder to my existing steering column. I starts and runs like a champ. I now have 4 codes. c1276, c1277, p1571 and p1689. My service vehicle light soon is on, trac off light is on and air bag light is on since I did not hook them up. The donor car had the front lightly hit and set off the two front airbags. It had side airbags too that did not deploy. I took the entire interior out of the 01 and installed it in 99 buick. I have pulled the interior wiring and will put it in later. Maybe I have to change the brake modulator too? Maybe the rear abs on my 99 buick regal is not registering? I don't know yet. I say this loud and clear the difference between supercharged cars and non super charged is a huge difference. Especially if body control modules are different. If you want a supercharged car spend the money and buy a supercharged car its definitely easier even if you have a donor car. If I had to buy all the individual parts It would have cost an arm and a leg. I kept the 99 supercharger tranny combo, with engine ecm, body ecm, steering column with the correct key for the bcm, engine harness, dash harness, and probably the brake control module for the bcm. Short story shoot me if I choose the attitude....I can make it run. I am so tired..... Any help on the body codes would be appreciated. I realize they are all traction codes, But why are they there? Thanks
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