hey guys! Do you think its possible to use a MSD 6AL to operate fuel injectors instead of an IGN coil? Does anyone have the amp/voltage outputs the MSD supplies to the coil? I was thinking it was 13.8 volts at 6 amps,,, is this correct?? ChadS
You might ask ChadS. He's pretty good at this stuff. Wait a sec. Imposter! If no one else jumps in soon, I'll ask the guy who got my EFI going and see what he says and report back. Are you having problems or are you just tinkering?
Rick! I built a EFI fuel rail for a 50's 6 cyl engine with ford injectors. I figured,, that if a MSD's multiple pulse discharge works on a 12V coil, why not a 12 volt fuel injector(s)?? If I can get it to work, its EFI without a computer. Ive been trying to fuel inject every carburated motor I can these days. HAHAHA!! How have you been? The one and only,, ChadS
Im thinking if Ican borrow the trigger signal from the distributor, hook the MSD up to that connection,,, the MSD might power the injectors with a triple pulse band. Im also thinking about the injector timing,,,,,, so i have a MSD timing control box added to my 6AL, to advance or retard the injector timing to help dial in a proper timed sequence. All the injectors are wired and fire all together on this engine,,, 2 cyls per port on this engine so I belive it to have a constant vacuum signal thru the port, therefore,, needing a constant fuel supply from the injectors to that port. (3ports total) The IGN will still operate in normal functions,,, or I can add another MSD to control the timing too! Either way, Im trying to do something unheard of with parts never intended for what Im doing. But, anything is possible,,,, right??? Chad
The computer changes the pulsewidth of the injector signals according to the engine's needs for more or less fuel, similar to the metering circuits in a carb. How do you plan on accomplishing that? Not trying to burst your bubble here, just wondering what you have in mind.
The signal speeds up as rpms increase, signal slows down as rpms decrease. I will control how much fuel enters by setting the fuel rail pressure while on a dyno at my target rpms. I can also incorperate the carburator if I need help with the idle,, till I figure something better if it dont work. Im using the stock carb as a throttle body,, single barrel carb,,,, 3200rpms max. I have a electric fuel cut off on my carb,, so I can turn on the carb and shut of the carb's fuel supply at anytime,,, The pulse bands will at a constant rate,,,, but changes by engine rpm. at least,, thats what Im hoping it will do. chad
I kinda have an idea of what you're trying to accomplish (and it sounds like you're well on your way). BTW, does the EEC send a "-" or a "+" signal pulse?? (I dunno - just wondering). Sounds like you might have to blow something up to find out your answer on this one. Ha! What's the engine and application ("3200rpms max")? Good luck, if anybody can do it, I have faith that you'd be the one to do it.
Rick, its a tractor! A 1958 Farmall 460 with a C-301 6 cyl IH gas engine. The computer controls the negative side of the componets. MSD does the same thing too! its either gonna go,, or its gonna blow!!! HAHAHA!! Im trying to inject alcohol into it (methanol) But starting with gas for now till I see everything works out. They put that same motor in the IH trucks,, Im shooting for 300 hp out of a 5.0 6 cyl. Chad
Oh yeah! Fire dept on stand by! LOL! Ive looked bout everywhere to find a triggering device without a computer,, but heck I am not spending 3000+$ to do this. HAHA! I may en up putting a SD ford computer off a 6 cyl on it! Chad
Wait a minute...Am I off base here or what? I wasn't aware that the injectors were fired by the coil in the first place. I thought they were fired by the ECU, which changes the pulsewidth according to various sensor inputs? If I am understanding correctly, you just want to trigger ("fire") the injectors from the coil's trigger. I'm not sure you'll be able to tune it very well that way. How will you modulate injector pulsewidth to tune for various load conditions? Now, on a tractor, it may not seem like that big of a deal to make it all work, but on an automotive application, you're goign to have a tough time making it flexible enough to adjust for varying loads and engine speeds. Not saying it won't work....but it's going to be tough, and when you do get it lined out, it will definetly be one of a kind! Keep us posted on progress.
A ford distributor send the ecu information on crank postion, or cam postion,, Im thinking cam postion since it comes from the distirbutor. The notches on the distributor are cut specially so the ecu can idnetify each injector, a wider notch tell the computer its on number 1 and starts the sequences over again. Since it comes off the distributor,,, its like a points/pick up pulse that the coil uses to fire the plugs,,, the same mannor goes for the injectors. What I wanna do is hijack the outgoing pulse from the points or elect pick up to operate the MSD, the MSD then sends multiple pulses to the injectors, just like it would to the coil,,, Im thinking it may be the same voltage to operate. As far as being able to tune it,, If the MSD works,,,,, I can add the timing control feature, and dial in a better timed responce, I can advance the signal, or retard the siganl to help the actual injector timing. Now, then comes the problem,,, if it dumps too much fuel and floods,,,,,, I built this fuel rail, I made a "pill" that is just like a carb jet,, the smaller the jet, the higher the rail pressure, the larger the jet the lower the rail pressure wil be. I belive I can set the rail pressure manually while its on a dyno, keeping a close eye on plug colors under certain rpm load,,,, Only thing that can change the pulse bands is engine rpm,,,,,,for this design,,,, faster the engine runs,, the faster they will pulse,, slower rpms, slower pulses. Ive seen a few FI srtup for the older GM's,, and its kinda off the same principle,,,, set the line pressure, jet the orface so it dont flood out. Its very primitive,,,,, but the possibilites are beyond me!! LOL!!!! Chad
By "MSD" I assume you are refering to a CD multi-spark box? The output of those things are several hundred volts.
Yeah, I called the tech line today,,,, 450-480 volts at a capasitive charge. If you think about this,,, a normal 12 volt coil,,, 13.6 max running,,, is getting shot with a 450+ volt charge!!!!! DAMN!!! Thats alot of juice!!! Shoot, Ive seen Ford coils get hot and boil over with resistors in the leads. with way less that 13.8volts!! I wonder if the capasitor inside can be removed?? I know its 12v going into that thing,,, goes thru the chip board, and activates that capasitor that makes the 480v. then its a triple pulse at 12 volts??
