Would not this be a upgrade that would sell. Why not have water-jet or CNC made brackets and build kits to sell. Its a great idea to update our ignition systems.
Since the spec's say it can run off of 5v-24v, I've done at least a first pass tied it right into the TPS ref 5v and ground on the relay board. If I find this causes issues with the TPS (only used for accel shot and flood clearing) then I'll rewire accordingly. The sensor wires actually reached my firewall without adding wire :shock: So for the moment it's running unshielded, but I do have the shielded tach wire still running to the pickup coil in the HEI, it'll be an easy switch over if I do have electrical issues. I expect less issue out of a Hall sensor than a VR, but I could just be naive. To do this again, I have $3 in 3ft aluminum box tubing, $3 in 3ft of aluminum angle stock, $35 in a junkyard '90 Escort trigger wheel and machine work to modify a pulley and trigger wheel, then apparently $20 in a sensor. There are misc. cost of the bolt, rivets and spring pins to hole the trigger wheel. So it's still a ~$61 mod after the EFI conversion. From a thread currently going on another forum about coil on plugging about any V8.
Thank you Paul! I tried running it with out a pull up circuit (I'm no electronic wiz), and didn't get a tach signal, so I bumped it up to a 12v feed and tightened the clearance up on the sensor to about 1mm, and still nothing. So I headed down to radio shack and picked up a pack of 3k resistors (they didn't have 2.7k), wired it into the harness in the engine bay and bingo, I had a tach signal! Flipped the fuel pump kill switch back on and the car fired right up! whoo hoo. The timing is a bit off, so I need to go and calibrate the trigger angle, but so far so good. Thanks again for those links and recommendation :TU:
The recommended shielding is good, keep it short and away from ignition wires. A stock magnetic pickup generates a signal with no pullup resistor. That Cherry sensor definitely must have a pullup to have any output signal. Remember 12V wiring can be subject to spikes, I have seen up to 300V when cranking. Under a microsecond, too short to hurt a light or coil, but can blow a transistor. To protect your sensor, use a filtered supply from your engine computer to the sensor and pullup. 5V might be fine, check what voltage the computer wants. Bruce Roe
I have it running off a 12v feed supplied by the MegaSquirt now, grounded similarly. I have the wires running as far below the sparkplug wires as possible as it goes under the cap. Eventually I'd like to go to LS coils mounted on the valve covers, but that presents a breather and oil fill issue, so still sorting that out in my head. I have the trigger angle dialed in now and the tach signal is rock solid across the rpm spread.
Great job! :TU: Having the engine fire up and run after all your work is definitely a feel good situation. :grin: Paul
Thanks, it really is. It's times like this though that really show I'm not an electrical wiz that some people think you need to be to go EFI. I had someone on another forum explain to me what a pullup circuit does, lol. You'd think I'd know that by now? =P
That's one of the reasons we are here, to combine all of our skills and knowledge to help each other succeed. It's really incredible if you think about it. I'm still willing to make a sensor bracket out of solid stock with a slotted hole for sensor adjustment. Just pay for shipping Paul
I know it has nothing to do with your particular build, but you'd know better than anyone. Is it possible on a Buick motor to mount the sensor ring behind the balancer? I was checking out a setup that mounted a ring inside the timing cover of a chevy motor and could be used on other applications, but it has to be mounted behind the balancer and preferably inside a spaced out timing cover. I was thinking of maybe adding a small cover to the front of the timing cover, behind the balancer, as a sensor ring housing. I'm not sure if the balancer can be moved outward at all though. I imagine it'll cause issues with belt alignment at the very least.
As you mentioned, it would need the balancer moved outwards as the clearance behind the balancer is very small due to the oil pan. I don't know what keeps the oil slinger from rubbing the timing cover, but a disc with windows (as opposed to teeth) could probably be welded to the slinger (to provide 2-point contact with the crank snout for stability) and a hole drilled in the timing cover with an o-ringed sensor put in it to read the windows in the disc. Thanks Paul, but I think I'll run with this locked down set up. I pulled the second washer out of the end of the mount (first picture) and it centered up the sensor perfectly with the trigger wheel.
Car is still running good. Starts up quick. On to chasing other computer controlled mysteries. The auto-idle rpm targeting doesn't seem to like below freezing conditions, so that's the next thing to sort out. I could always go back to a straight coolant temperature controlled IAC movement.
Josh at Yoshiefab http://yoshifab.com/store/index.php?_a=viewProd&productId=45 built a unit for me for a buick 455. Long term project but slowly putting together the pieces.
I didn't see any pictures of the mount. pmueller offered to make a nice sensor holder for me (and I bet it'd look awesome). Currently, I now have around 2,000 miles on this set up and it's working like a charm. The auto-idle rpm targeting is working pretty decently too, didn't have to reset the idle at sea level or back at 6500ft. Having a slight hiccup with some setting when I lift on the throttle quickly (like while shifting or sitting in traffic) causing the idle to rise to ~2,000rpm and taking 3-5 seconds to settle, but it's a setting I just need to sort out, minor annoyance.
I'll additionally mention that yoshiefab also has a 24-1 wheel for the optical pick-up inside the CAS. I plan to try this approach for full sequential inj. and distributorless spark.
I don't plan to ever go sequential on this engine, but a Grand National cam sensor with a 455 gear on it drops right in and gives a good enough reading for sequential injection. I want one just to drive the oil pump, but am now considering cutting down a 3.8 distributor and just run the oil pump.
Cool thread. Keep up the good work, if your looking for a cam sensor try looking in the parts for sale on turbobuick.com I saw quite a few in the $40 range a few days ago.
It's been a long while since I updated this but figured now is the time since I have two sets of 8 LS coils headed my way to truely go distributorless. I also have since converted the HEI pickup coil to a cam sensor. In well over a year since I installed the trigger wheel on the crank I've had zero issues with it, as well as the bit over a year with the sensor mount, also zero issues and still rock solid tach signal. The cam sensor mod I did to the HEI is pretty crude but works perfectly and I have been running sequential fuel injection since about May of last year, which was chronicled in my project thread here. First I marked which tooth I was going to keep on each the reluctor and pickup coil. Pulled the distributor apart. Pulled the pickup coil apart and ground all the teeth off except one. The picture of the reluctor didn't turn out but I did the same on it. Set the crank to ~30* before the missing tooth (3 teeth). Then lined up the pickup coil and reluctor. Done, the cam sensor flags the next missing tooth as TDC on #1. This works like a champ. Here is a tooth logger data log from the MegaSquirt III. I originally had the cam tooth on the wrong side of the missing tooth which showed up in these posted logs. Here is a zoomed out view. The Green line is the trigger point the MegaSquirt uses, and the blue is the tooth counter and you can see the gap where the missing tooth is. The red line at the bottom would have spikes if there was an error syncing up the cam with the crank sensor. Aka it only counts say 340 teeth between cam signal spikes. Zoomed in. You can see the cam signal is coming in near the end of the third tooth AFTER the missing tooth. Again I fixed this after I took the picture. Here is a view of the duration logger rather than the trigger point logger. You can pick if you want the tooth to be read on the rising edge or the falling edge. This is important if your cam trigger and missing tooth are set very close to each other, as is in some OEM applications. I'll update this again when I get to actually mounting up the 8 ignition coils, which I hope to do in the next month or so when I put my engine back together (heads are out for porting if you haven't kept track on my project thread).
I got a couple of sets of coils in the mail today. One set for the Skylark, and a set for the OHC six engine. I also got a spare set of 4 for the Skylark. I had picked up a set of ventless (passenger side) valve covers for the 455 to mount coils on. Because they are ventless I have to figure out how to modify them to put oil in the engine and a breather on it. However, with the spare bracket I think I might be able to cut the bracket into three pieces, 1 coil, 2 coils, 1 coil, and make room around the breather and oil cap with out too much trouble. Could be easy. Of course I might look at ditching the coil bracket and simply make mounts on the valve covers to directly bolt the coils too. I think with some clean up these will look pretty good. Lines up pretty good with the spark plugs. Once cleaned up I think they'll look good! And for the heck of it, the Pontiac OHC six.