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Working on a car now with a 24x system on it. it runs, but not good. Ignition is not firing every time and drops out randomly. if you can get the car to rev up above 3500 or so, it will clear up and spark becomes stable and it sounds better in that range. (i am watching spark with my timing light on each of the cylinders) it will idle, but has a roughness to it.
so, all the wiring and pcm parameters are correct. we have checked all that multiple times. we have gotten a seemingly correct waveform on the scope at one point. engine is built with aftermarket crank, unknown timing set, and i dont know if there is any spacers behind the reluctor. Thrust is fine. 96-97 timing cover. we changed to a good set of 30# injectors and heat range 5 plugs to help with the fouling we were getting. (had 95#'s and heat range 7 previously)
the crank sensor is not centered on the reluctor ring.... looks to be too far foward by .080" or more. my intuition tells me the thing is not reading the reluctor clearly, and is on the ragged edge of being all the way off the edge of reading at all. sometimes it reads, sometimes it doesnt.
what do you guys think? does anyone have experience with a poorly adjusted crank position sensor, and how far off was yours?
unless anything changes, i will be tearing it back down and fixing this issue.
I had a similar issue late last year when I put my 24x kit on. At 5500, the car would fall on its face because it lost signal to the crank sensor, but after countless hours of trouble shooting and phone calls, we shimmed the crank sensor using standard GM crank sensor shims.
Once the shims were added, it would rev to 7k smoothly. At that point, we thought we were out of the woods but then it developed an issue with it "missing" at low rpm under load from 2k - 3500k. Once above that, it clears up. Re-shimming it by adding more or less .010" shims only made it worse.
At this point, the tuner and I truly believe it is a crank sensor/reluctor wheel issue, but I gave up on it for the moment. Been trying to enjoy it rather then sitting in my garage or the tuners garage and having to throw more money at it.
Thanks for the info. This car acts similar to yours in that it is missing down low and especially under load, but clears up probably somewhere around 3500 or so like yours. The car is probably going to be in my hands this weekend, so in another few days I will get it torn down. I am going to measure everything to put it EXACTLY dead nuts in the middle of the crank sensor. I am also going to measure the clearance between the reluctor to sensor. Also going to measure the cam gear face to make sure cam sensor is ok. I will try and update this once I get everything sorted out.
Thanks for the info. This car acts similar to yours in that it is missing down low and especially under load, but clears up probably somewhere around 3500 or so like yours. The car is probably going to be in my hands this weekend, so in another few days I will get it torn down. I am going to measure everything to put it EXACTLY dead nuts in the middle of the crank sensor. I am also going to measure the clearance between the reluctor to sensor. Also going to measure the cam gear face to make sure cam sensor is ok. I will try and update this once I get everything sorted out.
Forgot to mention that when looking at the reluctor wheel, mine also sat forward in reference to the timing cover opening. I am using EFI Connection's reluctor (for double row timing set) and EFI billet timing cover.
As far as distance from sensor to reluctor, there should be at least a .030" gap between them. If the front crank bearing has excessive wear, you may need to shim it more.
Here are the shims on EFI's site. (Which were not available through them when I bought the kit last year) Also, they have a better explanation as to why you need to use them in certain cases. https://www.eficonnection.com/home/p...ensor-shim-kit
I wouldn't worry about the cam sensor because my understanding is that it is only used at startup. If the cam sensor wasn't reading right, the car wouldn't start.
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24x crank/reluctor issues 
