I've been having some starting issues with my car and I can't figure it out because the issue is so intermittent.

For some background, the car is tuned on AEM EMS V2, with an old comptech supercharger kit, ACT pressure plate and street lite flywheel with OEM clutch disc, 1000cc ID injectors with a 450 walboro fuel pump and Science of Speed hard wire kit. I've always had a weird starting issue on a cold start. After the supercharger install and having the car tuned, occasionally the first crank will "lock up" and I'll have to try again before it cranks and fires. The starter was original and would stick. Which I understand is a common problem with S2000s.

Over the last year or so, I've had an issue where the car randomly will not crank and will not start. I can hear the starter solenoid engage and the starter gear extend, but it will not crank. My first thought was a weak battery. Tried charging with no change. I had the battery tested and it was bad, so replace it. Again no change. So my next thought was the starter had gone bad or was sticking. I turned the engine over by hand a few times and heard what I thought was the starter gears retracting. I thought the starter had failed and stuck, so I replaced it with a reman unit. That resolved the issue for a bit.

A while later, same problem. I again went through the same steps I went through the first time. The car can sit for awhile and I don't have a trickle charger, so I charged the battery and had it tested again. This time, the battery was in perfect health. I thought that the reman starter was possibly bad, so I replaced it with a new Bosch unit. Again, problem solved. I should not that I bench tested the old starter and it worked fine then. I chalked it up to not having enough strength to actually turn the engine over.

Another time later, it happens again. This time, I invest in a trickle charger because the battery is low on charge. I charge the battery and set it on the trickle charger. This time, I get a crank or two and it stops, similar to what I had been experiencing after my modifications. I try again. And now it won't crank. I go and purchase a multimeter so I can monitor the system while I attempt to start, thinking is a signal issue. Get the multimeter hooked up, and the car starts. The only difference this time is it had been on the trickle charger for about a week before I purchased the multimeter. I think to myself that it must be a battery issue and I need to be more diligent in keeping the battery healthy. From then on, whenever the car is parked at home, it's on a trickle charger. I had no problems for about 3 or 4 months with this set up.

Until today. I take the car out for a quick errand or two. It's starts up fine and I run my errands. I make 3 or 4 stops during that time and have no issues. I get home and park for about an hour. I had not hooked up the trickle charger as I needed to do some work in the garage. An hour later, I'm ready to move the car back in and the issue presents itself again. Again, no crank no start. I can hear the solenoid engage and the starter gears extend just like before.

I'm not really sure what else to check, other than forking out for an OEM starter. I thought that maybe the flywheel was damaged or not installed properly and it was causing things to bind, but I had the clutch and flywheel replaced a good year before I installed the supercharger kit without any issues. I also thought it might've been an immobilizer problem, but that gets eliminated with the AEM EMS.

Does anyone have any thoughts on this? This is making me not trust the car as I'm worried it'll happen away from home (thankfully every time this has happened the car has been at home). I've never had any issue with the car otherwise.

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I've been having some starting issues with my car and I can't figure it out because the issue is so intermittent.

For some background, the car is tuned on AEM EMS V2, with an old comptech supercharger kit, ACT pressure plate and street lite flywheel with OEM clutch disc, 1000cc ID injectors with a 450 walboro fuel pump and Science of Speed hard wire kit. I've always had a weird starting issue on a cold start. After the supercharger install and having the car tuned, occasionally the first crank will "lock up" and I'll have to try again before it cranks and fires. The starter was original and would stick. Which I understand is a common problem with S2000s.

Over the last year or so, I've had an issue where the car randomly will not crank and will not start. I can hear the starter solenoid engage and the starter gear extend, but it will not crank. My first thought was a weak battery. Tried charging with no change. I had the battery tested and it was bad, so replace it. Again no change. So my next thought was the starter had gone bad or was sticking. I turned the engine over by hand a few times and heard what I thought was the starter gears retracting. I thought the starter had failed and stuck, so I replaced it with a reman unit. That resolved the issue for a bit.

A while later, same problem. I again went through the same steps I went through the first time. The car can sit for awhile and I don't have a trickle charger, so I charged the battery and had it tested again. This time, the battery was in perfect health. I thought that the reman starter was possibly bad, so I replaced it with a new Bosch unit. Again, problem solved. I should not that I bench tested the old starter and it worked fine then. I chalked it up to not having enough strength to actually turn the engine over.

Another time later, it happens again. This time, I invest in a trickle charger because the battery is low on charge. I charge the battery and set it on the trickle charger. This time, I get a crank or two and it stops, similar to what I had been experiencing after my modifications. I try again. And now it won't crank. I go and purchase a multimeter so I can monitor the system while I attempt to start, thinking is a signal issue. Get the multimeter hooked up, and the car starts. The only difference this time is it had been on the trickle charger for about a week before I purchased the multimeter. I think to myself that it must be a battery issue and I need to be more diligent in keeping the battery healthy. From then on, whenever the car is parked at home, it's on a trickle charger. I had no problems for about 3 or 4 months with this set up.

Until today. I take the car out for a quick errand or two. It's starts up fine and I run my errands. I make 3 or 4 stops during that time and have no issues. I get home and park for about an hour. I had not hooked up the trickle charger as I needed to do some work in the garage. An hour later, I'm ready to move the car back in and the issue presents itself again. Again, no crank no start. I can hear the solenoid engage and the starter gears extend just like before.

I'm not really sure what else to check, other than forking out for an OEM starter. I thought that maybe the flywheel was damaged or not installed properly and it was causing things to bind, but I had the clutch and flywheel replaced a good year before I installed the supercharger kit without any issues. I also thought it might've been an immobilizer problem, but that gets eliminated with the AEM EMS.

Does anyone have any thoughts on this? This is making me not trust the car as I'm worried it'll happen away from home (thankfully every time this has happened the car has been at home). I've never had any issue with the car otherwise.