I'm trying to find the images or specs to make a crank trigger bracket to convert the stick 2.8 to DIS. I found some links in archived posts, but they seem to be broken-I can't access them.
I'm trying to find the images or specs to make a crank trigger bracket to convert the stick 2.8 to DIS. I found some links in archived posts, but they seem to be broken-I can't access them.
I thought WOT-Tech used to have an external 6+1 crank trigger, but I can't find it on their site.
I wonder if you could accomplish the same with a modified distributor to spin a 12 + 2 trigger wheel since it turns half the speed of the crank and accomplish the same. I'm not sure cranking speed would be fast enough for a sufficient hall effect signal to trigger ignition. I don't recall if there was a design produced for the multi belt system of the Fiero and I remain apprehensive of the few arrangements where signal notches were placed in the outer ring of the harmonic balancer.
I wonder if you could accomplish the same with a modified distributor .......................................
One of my boats had a 4.3 engine with a modified distributor. Solid state. No cap or rotor button. It used a coil pack and an ECM. A Yamaha outfitted engine. Will the 4.3 distributors fit the Fiero?
In jdv's link, it lists an 88 Beretta. That engine was a 2.8 and used coil packs. The sensor kit for that engine should work on the Fiero 2.8.
Not sure where you got that about the Beretta; the page is listed under "Do-It-Yourself > Engine Swaps & Conversions"... here's the product description:
quote
This remote crank signal trigger allows you to use your stock 3100 or 3400 rear crank sensor to run a 3500 engine. The 3500's reluctor wheel on the crankshaft is different, preventing you from being able to use a stock 3500 sensor.
The 3500 had a 24x wheel like an LS engine, so if you want to use engine management you already have but drop in an LX9 in place of 3100 or 3400, you can use this.
I agree that this unit should work on a Fiero 2.8 to use a 6+1 ECM... but since it's designed for the LX9 3500, the sensor mount might need some work to bolt up to a 2.8.
[This message has been edited by Will (edited 07-29-2021).]
The 3500 had a 24x wheel like an LS engine, so if you want to use engine management you already have but drop in an LX9 in place of 3100 or 3400, you can use this.
I agree that this unit should work on a Fiero 2.8 to use a 6+1 ECM... but since it's designed for the LX9 3500, the sensor mount might need some work to bolt up to a 2.8.
Those triggers are designed to mount to the face of an LX9 balancer/pulley, mounting one to a 2.8 will push the crank pully further from the engine, and prevent the accessories from lining up. it may be possible to machine the center out and weld the trigger ring to the crank pulley, but I'm not sure. if memory serves me right, most guys converting to DIS machined the notches into the balancer and made a bracket to hold the sensor.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
Will, I agree. I just saw the 88 Beretta listed at the left and didn't go any further. I was assuming it that was a listing of cars the sensor was compatible with. And yes, everyone, I know about assuming.
I wonder if you could accomplish the same with a modified distributor to spin a 12 + 2 trigger wheel since it turns half the speed of the crank and accomplish the same. I'm not sure cranking speed would be fast enough for a sufficient hall effect signal to trigger ignition. I don't recall if there was a design produced for the multi belt system of the Fiero and I remain apprehensive of the few arrangements where signal notches were placed in the outer ring of the harmonic balancer.
Hall works at near zero-speed (limitation is due to establishing a stable crossing threshold, not the Hall effect itself), and the signal is not speed-sensitive. It's the coil-based transducers that have a signal which is proportional to RPM.
A trigger wheel in the distributor could work, but then the wheel could be affected by slack in the timing chain and helical gears. I don't think the timing would be as stable as with a crank trigger.
It might be possible to do the 12 + 2 by replacing the stock star wheel with a 12 + 2 wheel, and by using a pair of fixed fingers to return the flux to the shaft, all while keeping the stock pickup coil, which could interface with the DIS brick. There may be also something to gain by replacing the stock magnets with stronger more modern magnets.
GM already put notches on the OD of the harmonic balancer of stock Fieros, and they didn't blow up, so I don't see the problem with adding more.
[This message has been edited by pmbrunelle (edited 07-29-2021).]
Hall works at near zero-speed (limitation is due to establishing a stable crossing threshold, not the Hall effect itself), and the signal is not speed-sensitive. It's the coil-based transducers that have a signal which is proportional to RPM.
A trigger wheel in the distributor could work, but then the wheel could be affected by slack in the timing chain and helical gears. I don't think the timing would be as stable as with a crank trigger.
It might be possible to do the 12 + 2 by replacing the stock star wheel with a 12 + 2 wheel, and by using a pair of fixed fingers to return the flux to the shaft, all while keeping the stock pickup coil, which could interface with the DIS brick. There may be also something to gain by replacing the stock magnets with stronger more modern magnets.
GM already put notches on the OD of the harmonic balancer of stock Fieros, and they didn't blow up, so I don't see the problem with adding more.
The bigger issue I see with adding notches to the stock balancer ring, is that they are known to slip over time and affect timing. I definitely wouldn't do this with an OE Fiero balancer, a new balancer would probably be ok though.
I picked up a NOS Fiero balancer, along with the Ford Escort sensor. Have a '7730 ECU, and the replacement distributor/oil pump drive, and coil pack. I was hoping I could find the CAD files so I could CNC cut the bracket. I can probably take the original timing bracket and extrapolate the sensor mount from that, but would be much easier to just find the CAD file.
f85gtron did this conversion. I believe he first did it on a 2.8 before dropping in a 3.4. He's out of Fieros now, but I'll contact him to see if he might be able to advise you.
f85gtron did this conversion. I believe he first did it on a 2.8 before dropping in a 3.4. He's out of Fieros now, but I'll contact him to see if he might be able to advise you.
I checked with 85gtron and when he did the conversion, he kept the distributor instead of going DIS. No sensor was needed. He used the signal from the distributor. He later went to a 3.4 and used the crankshaft sensor in the block.
