I own a 2004 Mazdaspeed Miata and recently have been having some I guess you could say "Strange Problems". I replaced my Fuel Pump with a walbro and replaces both my Cam and Crank sensor cause the car would die. Fixed both of the problems and the car ran great. It then started to shut off at times which I later found out was due to incorrect air gap setting on the cranks sensor. Which at the time was also tossing a p0300 and p0335. Fixed the gap and it ran great no problems but now im having a similar problem.... I don't know if im going crazy but I feel like my miata has lost some power in the past couple of weeks and is just not up to standards. Anyways I tried to recreate the scenario and it seems that anytime I hit a big bump or turn really sharp or jerk the car, that the car will completely lose power and shut off for 3-5 seconds with no response. If I pop it into neutral and coast the car will regain power like nothing happened and I can keep driving. I first thought it was just the engine shutting off but I had the radio on pretty high while driving to see if it cut out and sure enough it did.....Which means it has to be something electrical.... or atleast i assume. Anyways im stumped and any advice would be appreciated.

I should also add in the lately it takes longer than normal for the car to actually start....About 4-5 seconds or more to start sometimes, but then sometimes it starts right away

 

Check your battery, the hold down may have come loose and it's shorting on the body around corners.

 

Stock ecu still? Do the usual fixes. Clean the bog solenoid, maf, gap plugs. Double check the stock manifold that your rearward studs are still tight. Check for vac leaks etc.

 

I had a similar problem on a different vehicle. On that vehicle, there was a bolt under the dash that at some point had been replaced, and the new bolt was longer than the old bolt. Under the right bump/turning conditions that bolt would short out the electrical system momentarily, long enough to kill the ECU. Car would start right back up and nothing would be wrong.

My guess is you have a similar situation. Something is shorting the car out momentarily, long enough to kill the ecu but not long enough to blow a fuse.

 

Lol so sure enough Vitamin J was dead on with his answer....I went back to look at the battery and sure enough the bracket mount had moved all the way to the positive terminal. I thought this was strange and I barely pressed on the positive terminal and it started sparking out the ***....Moved the bracket back in the right position and so far have had no problem. I feel so stupid.... But thanks you all you guys for suggestions.

Also the Stock Throttle body tubes are know to slip off when they expand sometimes. Mind doesn't exactly slip all the way off but it does move a good couple of inches off the lip where it should be. Could this be causing a leak? It seems pretty sealed still but it's not all the way on for sure. In the mean time until I save up for the aftermarket tube im looking for a T-Clamp for it

 

Yes, it doesn't need to be completely detached to cause a leak. Is it? Spray some carb cleaner on it while it's idling, see if the idle changes.

 

Yea i'll test that out tomorrow. Just been experiencing a power loss when accelerating so I thought maybe that could be the issue. But no it does not slip off all the way. Just a couple of inches then it never moves from that spot. And no matter how tight I put the hose clamp on it still slips.....

 

If your throttle body inlet tube and diverter valve (BOV) are stock, they both need to be replaced. Rubber and plastic = fail. Both leak. Visit the MSM-specific site in my signature sometime. The gents here aren't always nice to MSM drivers since our cars aren't as manly as the big snail rides.

 

spark plug wire grounding out?