Let the fuel injection programming begin!
07-31-2003, 02:03 PM
#1
Three Wheelin'
Thread Starter
Join Date: Nov 2001
Location: Northern Kentucky
Posts: 1,446
Likes: 0
Received 0 Likes
on
0 Posts
Let the fuel injection programming begin!
Well, after lots of waiting time, my Split Second PSC1-009 programmable signal calibrator has finally arrived. The intake in the Bastard already has a MAF sensor (not yet wired) on the INTAKE side, where it belongs.
The PSC is pretty neat...in a nutshell, what it does is takes the input off of the MAF sensor (i.e. 0-5 volts), adds a 2.5 volt offset (i.e. 0 volts becomes 2.5 volts out) and sends this signal back to the stock L-Jetronic brain. There is a 2D map in the system to allow many correction factors to be entered to massage the output voltage to match the exact fuel flow of the engine's requirements. You can add or subtract 2.5 volts at any given point in 0.1 volt increments (based on input voltage). Basically, it is an analog to digital converter with high resolution. The main variable is voltage, but this thing can also read a tach signal for engine RPM (probably won't need it with L-jet maps). So, I get near stand alone programmable fuel injection control for $350.00. The unit comes with software which is now on my laptop.
The car is still running on the old AFM, so I have logged data with both the AFM and the MAF in their respective positions. Plot these on a graph, curve fit with the old French curve, figure in the correction factors and create the map.
The goal is to get the car to start up and run just like it does now....then I will incrementally crank up on the fuel pressure and make corrections in the PSC to cut the voltage to the L-jet brain low enough to have it run well at idle and off idle.
I hope to eliminate the 2 additional Microfueler controlled injectors and throw the fuel in through 8 port injectors as it should be. I figure I need 70 psig at the fuel rail to do this....good thing I have the hot rod Bosch Motorsports fuel pump. I just hope my J.B. Weld job on the gas tank holds up.
I don't have to worry about the MAF or AFM voltage doing anything to the ignition timing as it does on Motronic cars....I have the old tried and true mechanical distributor.
Now the fun is really starting....
The PSC is pretty neat...in a nutshell, what it does is takes the input off of the MAF sensor (i.e. 0-5 volts), adds a 2.5 volt offset (i.e. 0 volts becomes 2.5 volts out) and sends this signal back to the stock L-Jetronic brain. There is a 2D map in the system to allow many correction factors to be entered to massage the output voltage to match the exact fuel flow of the engine's requirements. You can add or subtract 2.5 volts at any given point in 0.1 volt increments (based on input voltage). Basically, it is an analog to digital converter with high resolution. The main variable is voltage, but this thing can also read a tach signal for engine RPM (probably won't need it with L-jet maps). So, I get near stand alone programmable fuel injection control for $350.00. The unit comes with software which is now on my laptop.
The car is still running on the old AFM, so I have logged data with both the AFM and the MAF in their respective positions. Plot these on a graph, curve fit with the old French curve, figure in the correction factors and create the map.
The goal is to get the car to start up and run just like it does now....then I will incrementally crank up on the fuel pressure and make corrections in the PSC to cut the voltage to the L-jet brain low enough to have it run well at idle and off idle.
I hope to eliminate the 2 additional Microfueler controlled injectors and throw the fuel in through 8 port injectors as it should be. I figure I need 70 psig at the fuel rail to do this....good thing I have the hot rod Bosch Motorsports fuel pump. I just hope my J.B. Weld job on the gas tank holds up.
I don't have to worry about the MAF or AFM voltage doing anything to the ignition timing as it does on Motronic cars....I have the old tried and true mechanical distributor.
Now the fun is really starting....
07-31-2003, 02:12 PM
#2
Inventor
Rennlist Member
Rennlist Member
John.. - supa kewl. That process would/will drive me nuts, as I'm a born-again tweaker, so I would/will be adjusting till the cows come home...
Now that they have the mapping, can we call up Spilt Second and order up our own Bastard (928) controller now?
Which MAF did you end up using?
Now that they have the mapping, can we call up Spilt Second and order up our own Bastard (928) controller now?
Which MAF did you end up using?
07-31-2003, 02:39 PM
#3
Three Wheelin'
Thread Starter
Join Date: Nov 2001
Location: Northern Kentucky
Posts: 1,446
Likes: 0
Received 0 Likes
on
0 Posts
I am using a Pro-M 75 mm Bullet MAF. This is a ford style and I have the 36 lb Mustang curve installed. This is irrelevant, since I am doing a direct calibration. You guys could easily convert over to this type of system with a smaller MAF and the Split Second PSC....talk with Mark and tell him I sent you there. Mine is custom made, based on data I gave to Mark. He did an excellent job for me. The quality of the unit is top notch.
07-31-2003, 06:50 PM
#4
Intermediate
Join Date: Mar 2002
Location: Iowa
Posts: 42
Likes: 0
Received 0 Likes
on
0 Posts
John, Been following your rebuild, good job. I'm in the process of gathering all the parts to convert my 78 from mechanical fuel injection to electronic. Manifold is off an 80, which just came back from the polisher's. Injectors were sent to Rich at Cruzin Performance to be checked and cleaned. They looked brand new when they came back. I have a Halltech F10-8 controller that I will be using for this coversion. Software is loaded on laptop and I think most of the fun will be in the tuning of the controller. Keep up the good work.
08-01-2003, 01:27 PM
#5
Three Wheelin'
Thread Starter
Join Date: Nov 2001
Location: Northern Kentucky
Posts: 1,446
Likes: 0
Received 0 Likes
on
0 Posts
Yes, re-mapping a fuel curve is no easy task. Luckily, I have a good baseline from which to start. And to think I am only doing one variable.
