We have been working on a customer's vehicle with an electronic injection unit supplied by Hilborn. We wired the truck, and set everything up, and the owner took it home to do some more work himself. He is now ready to start the truck up and he came in today with a question. The truck runs the carbine "computer" with the dials to set the "program", and an MSD 6A box. the issue is that he checked with the people who set these up for Hilborn, and they sent him NEW instructions, and told him that the power sources for the MSD and the computer MUST be separate. We have a power wire from the Bat to a junction block where both the MSD, and the computer connect. The computer then has a relay and a fuse. The MSD has a fuse. Will it really cause interference if these both pick up power at the same junction block, as opposed to both being on the same terminal on the bat?
what am I missing that would isolate the interference, if they both still connect to the same post, only at the battery not a junction block?
Hooking it up directly to the battery is gonna be the absolute "cleanest" signal possible - so I'm inclined to ask, "why fight it?" Moreso since the vendor seems to NOW require it - sounds like THEY learned a lesson on this too.
computers work on very low voltages and readings can be compromised by surges/drops in power.... especially when wired to something that builds power.
How many amps do each unit consume? Maybe the problem lies in how many amps it pulls, not that you have proper circuit protection. Also, grounds can cause more problems with low voltage/current draw items than with high draw circuits/components. Usually best to go with what manufactuer suggests, do to they have used more trial and error than most first time buyers.
we have wired a bunch of similar cars, but never with this computer. Before I tell the customer to haul his car across town for a few hours of work I would like to understand why it needs to be done. Hilborn claims that it is due to electrical interference from the msd, not in amp draw.
I see you wired it with the 28 page instructions and now you got a 45 page instruction andit wires totally different. Yes you need to do as he says and also you should use #8 wire if the batt is in the rear as well. Are you dealing with andy at hilborn? i had hell with a faulty tps that came with it, mine was a hat on a blower and at 1/8th inch open throttle the competer thought it was wide open and would go just that and try to bend the throttle plates in the hat. good luck.. and remember where the said dials were when you got it as that is usually in the ball parko already ..
Theres a guy here on the HAMB that is with Hilborn customer service, you could probably do a search and find his user name and PM him to get his input.....
[FONT=arial,geneva]EFI Spe******t: Phone (215) 643-4607 Fax(215) 643-4608 Call Andy at Hilborn. He is on the east coast. Tell him Wil Sakowski sent you from Sakowski Motors. He is a great guy and is totally on. Do what he says and it will work. I have worked with him on projects, to much success. My guess it that it wil work the way you have it, but it will work better or without the possibility of problems if you run the wires as specified. If there is anything you can do to provent problems, do it. I don't think it wil hurt it to run it the way you have now, but why deal with the headache. I also depends on what gauge the wire if from the junction box from the battery. ... Just hook it up right. good luck Wil www.sakowskimotors.com [/FONT]
I will agree that andy can answer any of your questions. I went through the same thing when i wired my electronic four port and i also have an msd 6. He had me run two seperate feeds from the battery. They need a real clean signal to work properly. If you have any questions just call andy. He's a great guy and will go to any length to help you out. G***er Girl
I will agree that andy is tons of help, and he got us through the initial install with some odd issues with this car. We are going to let the customer fire up the motor, and then rewire the msd when he brings the truck back to wire the tail lights. If we have any issues then I will call andy, but I would still like to know how connecting both to the bat "cleans" the signal.
I've run a couple on my dyno and you "can" run it from a block but you "can" have problems sometimes too. The engine in the picture is hooked up to a common buss bar. This is a Arias Hemi/Chevy with a bird catcher setup with the Carabine EFI
Connecting both supply wires doesn't "clean" the signal, but it helps avoid corruption in the first place. The battery is a fairly low impedance (resistance) source of energy. When you use a single wire from that source to supply multiple loads you invite what's called "load crosstalk". This is because the load currents from each load create voltage drops across the common length of wire due to the wire's resistance. These induced voltage drops can confuse the CPU and ***ociated circuitry in the fuel management system, also the sensors supplying the ECU with throttle position, manifold pressure, etc. Be just, or perhaps more careful with how you handle grounds. Since most of the sensors are referenced to ground they are sensitive to noise present between various "grounds" on the block, frame, battery terminals, whatever. Cheers, Mark
yeah, what mark/maw said. also, think of the battery as a vibration dampener, the closer you are to the battery, the better buffer it provides, both from accessory power loads switching on/off(voltage spikes), alternator 'noise' and circuit boards/computers. I install and troubleshoot relatively technical GPS systems on aircraft and incorporate another computer system to communicate with said GPS to control the hydraulic chemical dispersal system, we wire everything directly to the battery (with proper fuse/circuit protection) because of 'dirty signal'. if it's too far from the power source, even simple things like lights turning on/off will cause problems but the main thing is the little tiny voltage spikes/dips that are just part of circuit boards operating, (you can't even pick them up with a multimeter) will give eachother hell, intermittently giving you problems. an O/T example is the 94-98 dodge diesel automatic transmissions have an electronically controlled transmission, if the TCU isn't grounded close or directly to the batt, many(but not all) will intermittently have problems with locking/unlocking the torque converter and somewhat quickly will burn up the transmission. chips on circuit boards are retardedly sensitive to a 'dirty' power supply
I agree with Mark also. As another example, i work on Generaters and have found that the newer units with multiple engine components running off a magnetic pickup want seperate pickups for seperate components. At first they tried running them off of one Mag pickup but that caused intermintent problems. The solution was seperating the signals. After finally realizing this it stopped many headaches.
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