I have searched and ether can find what I'm looking for or to dumb to see it.
I am doing a 4.9 swap and had planned on doing it with a carb because I could get a motor cheap. Well things changed and I got a complete running car that was crashed for cheap. So now I have the computer and now want to keep the fuel injection. So here are a few questions.
86 GT and I'm running the stack 4 speed.
1. Can I run the stock Caddy ECM? I know the VATS has to be bypassed but is that all?
2. I've seen many people who did the wiring themselves. Is there someone who has a how to on building the harness.
3. I've seen someone post they would build the harness for a fee. Any links to that page?
4. I want to use the Caddy a/c compressor. Is getting the a/c lines made all I have to do?
The donor car runs and drives with only 76k miles. It is a one owner old lady who crashed it into someone and it trashed the bumper, headlights, grill and hood. Both airbags deployed. I just had the engine scanned at a buddies shop and it is trouble code free.
I have the carb'd 4.9 no regrets. More power and simple to administer. I don't think I'd take on the fuely setup but I can understand your temptation. Good luck with it.
I have the carb'd 4.9 no regrets. More power and simple to administer. I don't think I'd take on the fuely setup but I can understand your temptation. Good luck with it.
I was fallowing your build then just came up with a complete car and thought I would just keep the EFI.
Why would it need to be programmed for a 4 speed? The engine has no control over the manual transmission. And with the bypass box ($15 on eBay) why would I need it removed from the ECM?
I was fallowing your build then just came up with a complete car and thought I would just keep the EFI.
Why would it need to be programmed for a 4 speed? The engine has no control over the manual transmission. And with the bypass box ($15 on eBay) why would I need it removed from the ECM?
Do you want a working check engine light? It will be on constant.
No transmission hooked up will mean the ECM will have constant faults. That along with any other inputs that the ECM might be looking for that are missing. You will also have faults from the missing ancient vacuum cruise control.
Depending on the ECM, you can also get faults on the outputs. For example on a 3800 swap, if the fuel pump relay output of the PCM isn't connected to a relay coil it will show a fault. Same thing with the high speed fan. OBD2 does this quite a bit. Not sure if the 2240 monitors any/some/all outputs to see if there is a load out there.
If you want to get away without having the computer programmed you will also need to purchase a VATs signal generator, or you will have to take take the vats module, and the key reader and stick them somewhere under a seat and hope they don't fail.
[This message has been edited by phonedawgz (edited 10-22-2014).]
Do you want a working check engine light? It will be on constant.
No transmission hooked up will mean the ECM will have constant faults. That along with any other inputs that the ECM might be looking for that are missing. You will also have faults from the missing ancient vacuum cruise control.
Depending on the ECM, you can also get faults on the outputs. For example on a 3800 swap, if the fuel pump relay output of the PCM isn't connected to a relay coil it will show a fault. Same thing with the high speed fan. OBD2 does this quite a bit. Not sure if the 2240 monitors any/some/all outputs to see if there is a load out there.
If you want to get away without having the computer programmed you will also need to purchase a VATs signal generator, or you will have to take take the vats module, and the key reader and stick them somewhere under a seat and hope they don't fail.
This.
Not sure I enjoy his avatar tho
I have a 91 Seville that has the 4.9L. You should realize that the car utilizes an on board computer even tho it isn't OBDII.
This car has so many sensors and is constantly monitoring everything. You can't just take the engine and plug it into the 4 speed.
Well, the carb setup is sounding much better again. What does all this computer flashing cost? I looked at the price for the wire harness and it is about $500!!! That is almost what I paid for the complete running caddy.
Via the climate control panel you can view the ECM error codes. Something also to think about is that GM since they put that functionality into the climate control panel, left off the ALDL blinking check engine light to see the code function.
So you need to use an ALDL scanner, or ALDL cable and laptop or android, or bluetooth ALDL adapter to view the error codes. You however get the ability to see the sensors and view the ECM outputs also.
Not worried about the trouble code light. I have a buddy with a full Snap-on scanner. I just want it to run and drive. A/C and cruse would be awesome. This is a budget swap and why I didn't try the SC 3.8 engine. (I also like the idea of a V8 in this little car) parts for the carb set up would be $200-$300. Just thought if I can do the swap and cost close to the same as buying a carb and stuff, then why not.
A stock 4.9 uses the PCM (power train control module) to monitor and control the engine and transaxel. It also communicates with the BCM (body computer module). The BCM is what runs the on-board scanner/diagnostic system via displays on the ECC (electronic climate control), FDC (fuel data center), etc. The following sensors and switches are monitored and some can be adjusted manually and automatically to compensate for problems...
INPUTS: pass-key theft deterrent heated windshield servo position cam sensor HEI module (dist ref) throttle switch set/coast resume/accel cruise on/off throttle position coolant temp manifold temp battery voltage manifold pressure power steering pressure switch VCC brake switch(auto trans) PRNDL switch ignition switch oxygen sensor ALDL request
OUTPUTS: computer command ride controller HEI module (bypass est) idle speed controller cruise control solenoids check engine light a/c relay fuel pump relay VCC solenoid VCC mod solenoid shift A solenoid shift B solenoid low fan relay high fan relay speedometer injectors
The system is pretty complex and very in depth. It is a full time monitoring, data logging, code reading, wiring checking, switch testing, and switch output controlling system with the ability to compensate for many conditional changes automatically. The TPS (throttle position sensor) learn function compensates for carbon buildup on the throttle body for example. I've never seen another car with this complex of a system built in before. Pretty interesting actually and could be put into a fiero if one were a glutton for wiring punishment. he he. The 4.9 and 2240 PCM were one of the highest technology engine/computer setups of their time. It was basically the peak of OBD1 technology with a few exceptions (93-95 northstar, etc.). The engine died with OBD1. The service manual is a freaking phone book!
The 4.9 also has a few outputs that can't be ignored.
During wiring you need to put 12v to the power steering input on the PCM or the it will reduce engine output. A missing VSS (vehicle speed sensor) signal to the PCM will cause a similar effect. For manual install the auto trans inputs on the PCM must also be wired correctly to avoid issues with the ISC (idle speed control module). EGR is very difficult to remove as it effects many of the tables in the PCM programming.
The good news is most of issues are simple and PCM programming can solve a lot of them. You also get the option to adjust tire size to anything you can fit wheel wells, within reason. Cooling fan turn on/off temps can be set to whatever you want. And the 2240 PCM can control two fans. You can also adjust base and moving idle speeds which helps a lot for manual installs. Its well worth it in the long run. The simplest and usually the cheapest in long run is the have the chip reprogrammed and build your own wiring harness. Its time consuming but still only one wire at a time.
Oops. sorry for the long winded explanations. I can't sleep tonight.
[This message has been edited by Fieroseverywhere (edited 10-26-2014).]
I was fallowing your build then just came up with a complete car and thought I would just keep the EFI.
Why would it need to be programmed for a 4 speed? The engine has no control over the manual transmission. And with the bypass box ($15 on eBay) why would I need it removed from the ECM?
THIS IS NOT A " EFI VS CARB" THREAD.
But It is hoped that we can think of this forum as a place for debate without the adversity that sometimes accompanies it. I see nothing wrong with pointing out the advantages and disadvantages of carb vs EFI as members view them. I believe that this fits into the information presented on this thread.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
But It is hoped that we can think of this forum as a place for debate without the adversity that sometimes accompanies it. I see nothing wrong with pointing out the advantages and disadvantages of carb vs EFI as members view them. I believe that this fits into the information presented on this thread.
A stock 4.9 uses the PCM (power train control module) to monitor and control the engine and transaxel. It also communicates with the BCM (body computer module). The BCM is what runs the on-board scanner/diagnostic system via displays on the ECC (electronic climate control), FDC (fuel data center), etc. The following sensors and switches are monitored and some can be adjusted manually and automatically to compensate for problems...
INPUTS: pass-key theft deterrent heated windshield servo position cam sensor HEI module (dist ref) throttle switch set/coast resume/accel cruise on/off throttle position coolant temp manifold temp battery voltage manifold pressure power steering pressure switch VCC brake switch(auto trans) PRNDL switch ignition switch oxygen sensor ALDL request
OUTPUTS: computer command ride controller HEI module (bypass est) idle speed controller cruise control solenoids check engine light a/c relay fuel pump relay VCC solenoid VCC mod solenoid shift A solenoid shift B solenoid low fan relay high fan relay speedometer injectors
The system is pretty complex and very in depth. It is a full time monitoring, data logging, code reading, wiring checking, switch testing, and switch output controlling system with the ability to compensate for many conditional changes automatically. The TPS (throttle position sensor) learn function compensates for carbon buildup on the throttle body for example. I've never seen another car with this complex of a system built in before. Pretty interesting actually and could be put into a fiero if one were a glutton for wiring punishment. he he. The 4.9 and 2240 PCM were one of the highest technology engine/computer setups of their time. It was basically the peak of OBD1 technology with a few exceptions (93-95 northstar, etc.). The engine died with OBD1. The service manual is a freaking phone book!
The 4.9 also has a few outputs that can't be ignored.
During wiring you need to put 12v to the power steering input on the PCM or the it will reduce engine output. A missing VSS (vehicle speed sensor) signal to the PCM will cause a similar effect. For manual install the auto trans inputs on the PCM must also be wired correctly to avoid issues with the ISC (idle speed control module). EGR is very difficult to remove as it effects many of the tables in the PCM programming.
The good news is most of issues are simple and PCM programming can solve a lot of them. You also get the option to adjust tire size to anything you can fit wheel wells, within reason. Cooling fan turn on/off temps can be set to whatever you want. And the 2240 PCM can control two fans. You can also adjust base and moving idle speeds which helps a lot for manual installs. Its well worth it in the long run. The simplest and usually the cheapest in long run is the have the chip reprogrammed and build your own wiring harness. Its time consuming but still only one wire at a time.
Oops. sorry for the long winded explanations. I can't sleep tonight.
Great post. Im going to get it reprogrammed and build my owe harness. Just didn't know if I could test the engine before I got it programmed
But It is hoped that we can think of this forum as a place for debate without the adversity that sometimes accompanies it. I see nothing wrong with pointing out the advantages and disadvantages of carb vs EFI as members view them. I believe that this fits into the information presented on this thread.
i agree with Dennis here. Carbs on a 4.9L work very well. its been done many times, and they don't suffer at all from power loss if done properly. Naturally, the fuel economy isn't quite as good, but its not a huge difference if it is dialed in correctly.
I myself am an EFI man, and the sequential fuel injection of the caddy 4.9L is particularly efficient, but to each their own.
