- Actually it has a little jerk in it. Besides the driver!!!
- 2003 Mazda Miata LS MX5, 6-speed manual, 1.8 VVT engine, air conditioning, 150K miles, daily driver, owned about 2 years.
- Mostly stock but has coil-over shocks, BBS wheels, and a TVS900 supercharger from Fast Forward Miatas. The supercharger system is set up to run by the stock computer unless it is in boost. It runs very well.
- The problem is that it has an intermittent jerk feeling. Always a single jerk then it drives normally again. It doesn’t seem to have any particular things that trigger it. My best description of how it feels is to imagine someone had tied a long rope to the frame. I get up to speed then somewhere down the road, I run out of rope and it jerks the car slightly as it breaks the rope and keeps going.
- There are no codes. I have tried a different MAF, cam angle sensor, hotter plugs, pulled the fuel injectors out and cleaned them, transmission fluid change, synthetic oil, and soaked the piston tops with ATF.
- Any ideas? I have a new crankshaft position sensor and new fuel injectors on the way. What else can I try?
I'd go a different route with diagnosis. If you can beg, borrow or buy a scan tool with Live Data and Freeze Frame functions, pulling up the Freeze Frame data, monitoring the Live Data, and getting some enhanced diagnostics (Mode 6 data) might be the most useful thing you could do, even if you took it to a diagnostic mechanic for evaluation. Otherwise, you'll run out of guessing (and money for interventions) without getting closer to identifying the problem.
Sounds like a misfire, for which there could be many causes.
- LOL!!
Also ran Sea Foam and Chevron Techron thru it and changed the fuel filter.
Also checked for vacuum leaks with a camp-size bottle of propane.
How do I remove the (SOLVED) sign?
Removed.
Can you recommend a good scan tool? Thanks for all the replies so far.
Depends on how much you want to spend and what do you want to do with it. Search this forum to find more information.
Well, I always prefer to buy tools over paying some shop to do something I could have done. How much is it worth to me to solve it? I would hope $500 in tools and parts would get it done.
What do I want in a scanner? Hard to say dince I’ve only used them as CEL code readers. I suppose I need one such as described above. One that monitors all sensors including ABS, can record data while driving and can freeze frame the instant that the misfire (or whatever) happens. It also need to be pretty user friendly. I’m not a computer nerd by any means.
Do you know of one like that?
you should replace a dozen more things just to be on the safe side
I just ordered the OBDLink MX+ scan tool that works wirelessly with my iphone.