converting to fuel injection

jakes_hachiroku
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converting to fuel injection

Postby jakes_hachiroku » Thu Dec 29, 2016 6:52 am

hey guys, its dumbass here again hahah
so I sorted out my block issue and am just about done putting the motor all back together and ive been thinking about this for a while but have never done something like this before. and that is converting my dcoe weber setup to fuel injected. I guess my main question is what is the ABSOLUTE MINIMUM sensors I will need to run if I use an aftermarket manifold (mrp) and some aftermarket ecu. wouldn't mind the benefit of fine tuning with my high compression but also my weber are pretty sweet so if its to much of a hassel **** it! I ask what sensors are absolutely necessary because I basically have no harness I bough the car with these webers on the original motor and when I built another one I just kept them lol.
any help?

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s24a
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Re: converting to fuel injection

Postby s24a » Thu Dec 29, 2016 7:46 am

I guess my main question is what is the ABSOLUTE MINIMUM sensors I will need to run if I use an aftermarket manifold (mrp) and some aftermarket ecu.

A typical speed-density setup like the 20V blacktop uses will have the following:
o Crank sensor
o Cam sensor (if you want sequential injection)
o TPS sensor for throttle
o MAP sensor for intake manifold pressure/barometer
o Inlet Air Temperature (IAT) or Manifold Air Temperature (MAT) for induction air temperature
o Engine Coolant Temperature (ECT)
The above is a minimum set for a speed density system or a Speed-Throttle (N-Alpha) setup with barometer capability
The sensors have to be compatible with the type of aftermarket ECU you plan to run.
Good information is to Google "DIYAutotune" as they make system that can be used with most Japanese vehicles and can take Japanese distributor signals.

o Closed loop will require an Oxygen sensor in the exhaust, preferably a heated one for best response.

If you want a airflow system, the MAP sensor is replaced with a Vane Airflow sensor (VAF) or a Mass Airflow Sensor (MAS).
Again, the ECU and SW have to be able to accept these pieces.

You can use an EFI system simply for the injection, or go full-bore and also use them to control spark advance as well. If so, then possibly a knock sensor.

You might also want idle speed control, so in that case some sort of ISC motor or solenoid will be required.

Suggest you immerse yourself into the internet an read up on EFI systems and adaptation/installation of above to get a better handle on the level of effort.
If you want to calibrate it, that is another whole subject, but there are a lot of benefits that you can derive if you do it right.
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson

jakes_hachiroku
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Re: converting to fuel injection

Postby jakes_hachiroku » Thu Dec 29, 2016 8:27 am

s24a wrote:
I guess my main question is what is the ABSOLUTE MINIMUM sensors I will need to run if I use an aftermarket manifold (mrp) and some aftermarket ecu.

A typical speed-density setup like the 20V blacktop uses will have the following:
o Crank sensor
o Cam sensor (if you want sequential injection)
o TPS sensor for throttle
o MAP sensor for intake manifold pressure/barometer
o Inlet Air Temperature (IAT) or Manifold Air Temperature (MAT) for induction air temperature
o Engine Coolant Temperature (ECT)
The above is a minimum set for a speed density system or a Speed-Throttle (N-Alpha) setup with barometer capability
The sensors have to be compatible with the type of aftermarket ECU you plan to run.
Good information is to Google "DIYAutotune" as they make system that can be used with most Japanese vehicles and can take Japanese distributor signals.

o Closed loop will require an Oxygen sensor in the exhaust, preferably a heated one for best response.

If you want a airflow system, the MAP sensor is replaced with a Vane Airflow sensor (VAF) or a Mass Airflow Sensor (MAS).
Again, the ECU and SW have to be able to accept these pieces.

You can use an EFI system simply for the injection, or go full-bore and also use them to control spark advance as well. If so, then possibly a knock sensor.

You might also want idle speed control, so in that case some sort of ISC motor or solenoid will be required.

Suggest you immerse yourself into the internet an read up on EFI systems and adaptation/installation of above to get a better handle on the level of effort.
If you want to calibrate it, that is another whole subject, but there are a lot of benefits that you can derive if you do it right.




well right now my ignition is run off an msd 6al so that's covered so would it be possible to set something up for just air flow sensor, o2 sensor and injectors? or will an oem ecu or aftermarket ecu need more info to keep car running?

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s24a
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Re: converting to fuel injection

Postby s24a » Thu Dec 29, 2016 10:08 am

An engine control system will need to know the following:
o What is the position of the crankshaft for timing injection. So need a crank sensor. You can use the four pulses from a distributor for that information as it is already going to the MSD.
o Control system needs to know whether the engine is cold or hot, and HOW cold or hot. So you need an ECT. Air temperature is also nice to have for smoothing the fuel delivery.
o The control system also needs to know engine state (idle, part throttle and WOT), so you need a TPS.
This also gives information on where idle/part throttle transition occurs, and part throttle to WOT occurs. Rate of change of the TPS is used for acceleration transient fuel added to base pulsewidth, so this single sensor does a LOT in information regarding fueling.
o If you change altitude in your driving, then a barometric sensor is needed for compensation. The MAP sensor can do both jobs, as it will read barometric pressure on key-on and also can do it at WOT at low rpm.
o Adaptive fuel trim depends on an oxygen sensor, whether you run a catalyst or not. Helps with tuning.

So again, back to my list, and you see every sensor I mentioned has a purpose.

As you have a modified engine, I really think that no stock control system will exactly match what you want over your carburetors.

I still suggest you read up on EFI control systems. Find your local library and see if they have any books on the subject.
Books include how to pick and modify (as in hardware for installation) a system to install on your engine, with pointers on sensor placement.
There are also some good books on calibration of aftermarket systems, with some example systems given in these books.

This is NOT a novice endeavor, so you need to really do your homework before jumping in.

Just as a rationality check for you, I have about 40 years of experience in automotive engine/powertrain control systems that I am speaking from.

Hope this helps you.

Hank
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson

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jakes_hachiroku
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Re: converting to fuel injection

Postby jakes_hachiroku » Thu Dec 29, 2016 11:27 am

s24a wrote:An engine control system will need to know the following:
o What is the position of the crankshaft for timing injection. So need a crank sensor. You can use the four pulses from a distributor for that information as it is already going to the MSD.
o Control system needs to know whether the engine is cold or hot, and HOW cold or hot. So you need an ECT. Air temperature is also nice to have for smoothing the fuel delivery.
o The control system also needs to know engine state (idle, part throttle and WOT), so you need a TPS.
This also gives information on where idle/part throttle transition occurs, and part throttle to WOT occurs. Rate of change of the TPS is used for acceleration transient fuel added to base pulsewidth, so this single sensor does a LOT in information regarding fueling.
o If you change altitude in your driving, then a barometric sensor is needed for compensation. The MAP sensor can do both jobs, as it will read barometric pressure on key-on and also can do it at WOT at low rpm.
o Adaptive fuel trim depends on an oxygen sensor, whether you run a catalyst or not. Helps with tuning.

So again, back to my list, and you see every sensor I mentioned has a purpose.

As you have a modified engine, I really think that no stock control system will exactly match what you want over your carburetors.

I still suggest you read up on EFI control systems. Find your local library and see if they have any books on the subject.
Books include how to pick and modify (as in hardware for installation) a system to install on your engine, with pointers on sensor placement.
There are also some good books on calibration of aftermarket systems, with some example systems given in these books.

This is NOT a novice endeavor, so you need to really do your homework before jumping in.

Just as a rationality check for you, I have about 40 years of experience in automotive engine/powertrain control systems that I am speaking from.

Hope this helps you.

Hank



thanks man! yea I figured it was a lot of work so and finding the intake manifolds with sensors still on them is getting a little tricky. and its not like my webers have let me down yet! just wanted to know what im in for if I were to do such a transition. BUTTTTT at this point building the engine was fun and all that wire work does NOT sound as fun. ill just tune up my webers at the moment hahaha

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s24a
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Re: converting to fuel injection

Postby s24a » Thu Dec 29, 2016 3:11 pm

The type of sensors used will be dependent on the type of control system.
For example, a GM system from the mid 80s to mid 90s used ECT and IAT sensors that were a NTC (negative temperature co-efficient) resistive type.
Meaning that at cold temperatures the resistance was high, and at hot temperatures the resistance was low.
Crank sensors were Variable Reluctance style, meaning that the sensor sensed a piece of metal on the target wheel on the crank and gave a rising voltage output pulse folled by a negative pulse crossing 0 as the metal swept away from the sensor head.

But other manufacturers used Hall effect sensors (square wave positive-only output as a target wheel passed them).

So you need to watch out.
Finding a manifold with sensors doesn't necessarily give you the set you need for a particular type of ECM and control system.

If you get some literature on some systems, like Haltech, Autronics or FAST, you will start to see what I mean.

Hank
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson

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SR85DET
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Re: converting to fuel injection

Postby SR85DET » Fri Dec 30, 2016 4:38 am

jakes_hachiroku wrote: ill just tune up my webers at the moment hahaha


Well if you ever do decide to sell those Webers, please let me know! I am going for one car with FI and one carb'd. Both have their benefits and disadvantages. It's nice to only need a handful of wires with carbs (aside from ignition)

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