Hydra 2.17 randomly loses power- shuts car off
 

So this is a little battle I've been in for awhile now and now am stumped.

The Hydra seems to lose power/signal at random intervals. Sometimes within 1 minute of a dead cold start, sometimes 45 minutes into driving. I have noticed some particular issues under this condition.

When rolling and in gear- Two things. 1) Tach will dither 1 time down to 0 and pop back up. At this time, all power is lost until the tach returns to a RPM location. I've had this happen under acceleration (scary!) and while a light cruise and while engine braking. 2) The tach will cut out completely and not come back up. Under condition 2, it is required that I turn the key all the way back to OFF and back ON. If I am still moving and in gear, the tach will jump right back up and power is restored.

When stopped- If the car dies while stopped, I MUST turn the key back to OFF and then try starting the car. If it stalls and I just turn the key forward to turn the starter, the engine turns over buy never fires. Must turn key all the way back and then try again.

This issue used to just happen every once in awhile...but it's getting more frequent now and I'm starting to get annoyed....it's always fun when you're on a busy street making your way through an intersection and it just decides to ---- you and make you look like a n00b.

Halp? Has anyone seen this before?


Hydra 2.17 (I know I know)
Everything is a normal FMII add-on and no "extra" mods done to any sensors/electronics.

Crank or cam sensor. Sounds more like crank than cam, but cam is easier to check/replace.

Failing sensor for about a year?
I think I might have an extra cam sensor and will swap that out tonight. Cam sensor- I can get a used one (low miles) and see what happens. Some time ago I talked with Jeremy at FM and he said something about a 5v power supply in the Hydra....I think. Sometimes the problem is more frequent than others...so when it's not acting up, I don't really think about it.

Can you actually connect to the Hydra when this happens?

I have not tried. But I'll keep the laptop handy and next time I will try. I see where this is going. I assume if I cannot connect, the internal power is cutting. If I can, then it's a sensor. I didn't even think to try this.

I dont see what year ur car is but on my 99, disconnecting the cam sensor stopped the tech from working (0 rpm) however it did not affect the drivability at all. I'm running Adaptronic though.

have you ever jump started your car? I am DEFINITELY not an expert on the hydra but I have to say I agree the 5v regulator in the unit could be going bad, why else would it work after turning the key to off then back to start but not just from on to start? would it be possible that a voltage spike could have damaged the unit itself? I say the unit is at fault because every time you cycle the key from on to off then to start its like a reboot of the unit.

Voltage spike. Interesting. I think I jumped my car one time awhile ago, but this issue had already been happening.

This just reminded me of another issue thinking of voltage spike. The issue is sometimes when I first get in the car and start driving, the radio cuts out above a certain RPM under light throttle or when letting off the throttle to shift. I've noticed that if I turn on any accessory or add any single electrical load .. hitting the brakes to illuminate the brake lights, using myturn signal, turn the blower on, turn parking lights on etc... the radio comes back in. Symptoms of a voltage spike in the system?

Definitely overcharging.

What would cause this?
I did replace the alternator with what should have been a NB alternator about 6-8 months ago. I'd assume that if I had accidentally popped a NA alternator in there I'd have a different set of issues lol.

Might the overcharging and the power cut out be related?

Could be. Maybe the sensors don't like the extra voltage.

i know we dont run the same version but it seems to me i saw an email some months ago for a firmware update from fm addressing an alternator voltage regulation issue. maybe older versions have it too

Wrote an email to HydraEMS.

The reply was-


Yeah thanks a lot. I know my sh!t is old, but for f*cks sake, at least say if it sounds like a known issue or not so I'm not chasing down multiple things. Is it really that hard to help someone who isn't a recently paying customer? Hell, someone paid for the ECU...what does it matter how long it has been. Oh well. I guess I can get my hands on a crank and cam sensor and see what happens....though I have little hope that it will stop the issue. Next step would be to try the NA alternator.

Does or did your car have an aftermarket alarm? They're often spliced into the ignition circuit and can cause issues when they age (this happened to me, even though the alarm was long removed). Alternatively, you can do a rebuild on your ignition switch (fairly simple for a casual DIYer).

Here are FM instructions for the NA alternator swap, which helped my car a lot:

https://www.miataturbo.net/attachmen...ine=1339903843

Are you running NA or NB alternator

I had this issue

I was having overvoltage with the NB alternator.

This exact issue

I would read you r thread but i are drunkz.

Put the p in v

^Pretty sure he's running an NB alternator. Unless your running one of the latest versions of Hydra 2.7, the voltage regulation sucks. If you are running Hydra 2.1x, I would recommend the NA alternator swap. My car ran a lot better after I did this.

OK yah doppel you need to calibrate the alternator voltage.

You're getting overvoltages and hydra is cutting power. that is bad.

look at the FM manual it's in there

http://flyinmiata.com/support/instru...ECU_Tuning.pdf

This or you have a major short, probably at your battery.

The voltage the hydra displays is around a 1 - 1.5 volts lower than the actual output from the alternator. If the Hydra says bat voltage is 13.5 your closer to 14.5 - 15 volts witch will cause the Hydra to cycle on and off. Adjust the alternator duty cycle down until the hydra doesn't display over 13 volts its a pain.

+juan on NA alternator swap. Voltage control on the Hydra units is total friggin' garbage.

I have the same issues but not bad enough that it'll shut the car off. Or maybe... i'm not sure. I'm guessing it has something to do with my utterly horrible idle quality as well, which does sometimes stall out.