[Miata] '02 Miata Bucking Without CEL - Big Mystery!

[Bryan Wyatt]

While we're on the subject, are there any handheld readers that read pending codes?  I'm 99% sure the one I bought from my local FLAPS (that allows me to clear codes) can't read them.  Otherwise, this unit looks tempting--though I hope I get this thing solved now so it's not an issue.
 
Also, Bill, Larry's actually the second person I've heard mention a defective TPS.  Any thoughts?
 
-Bryan

--- On Tue, 5/27/08, Larry Alster <Larry at Miata.net> wrote:

From: Larry Alster <Larry at Miata.net>
Subject: RE: '02 Miata Bucking Without CEL - Big Mystery!
To: bryanewyatt at yahoo.com, "'Miata Power List'" <miatapower at miatapower.net>, "'Miata Mailing List'" <miata at realbig.com>
Date: Tuesday, May 27, 2008, 7:15 AM








It might pay to get an OBDII scanner that can log and drive around with it for when  the problem starts and see if you can find anything.
 
I use this unit   http://obddiagnostics.com/
 
You do need a laptop but you can set it up to log and you can also run it so all the functions are being shown on the screen at the same time so you can see the data real-time.
 
Bill could this somehow be TPS related since he says it only happens at partial throttle??
 
 
 
Larry
 
White Knight      1991 Crystal White   #99 CSP
Silver Bullet        1992 Silverstone     #17 SM2  FM I+ Turbo
Honey B             1992 Sunburst Yellow #99 SM2L  JR Supercharger
Whooosh           2004 Titanium Mazdaspeed MX-5
 
LowCountry Miata  http://www.lowcountrymiataclub.net
Masters Miata
RAGS 074
 

From: miatapower-bounces at miatapower.net [mailto:miatapower-bounces at miatapower.net] On Behalf Of Bryan Wyatt
Sent: Tuesday, May 27, 2008 7:05 AM
To: 'Miata Power List'; 'Miata Mailing List'
Subject: RE: '02 Miata Bucking Without CEL - Big Mystery!
 




I was thinking the same.  Knowing my luck, I could take it to the shop and probably have nothing happen...or it could happen on my way home.  

You know?  I went through crap like this with the old car (spent several months and a couple grand--probably--chasing down P0300's that never entirely went away).  I'm beginning to suspect that I just might be cursed...
 
-Bryan

--- On Tue, 5/27/08, Larry Alster <Larry at Miata.net> wrote:

From: Larry Alster <Larry at Miata.net>
Subject: RE: '02 Miata Bucking Without CEL - Big Mystery!
To: bryanewyatt at yahoo.com, "'Miata Power List'" <miatapower at miatapower.net>, "'Miata Mailing List'" <miata at realbig.com>
Date: Tuesday, May 27, 2008, 6:13 AM


I think I might discount the condensation thinking since you said this has happened before over 1000 miles ago.  Seems unlikely to me that the water laid around happily in the tank for over 1000 miles before acting up again.  Something that intermittent sounds more electrical to me.
 
 
 
Larry
 
White Knight      1991 Crystal White   #99 CSP
Silver Bullet        1992 Silverstone     #17 SM2  FM I+ Turbo
Honey B             1992 Sunburst Yellow #99 SM2L  JR Supercharger
Whooosh           2004 Titanium Mazdaspeed MX-5
 
LowCountry Miata  http://www.lowcountrymiataclub.net
Masters Miata
RAGS 074
 

From: miatapower-bounces at miatapower.net [mailto:miatapower-bounces at miatapower.net] On Behalf Of Bryan Wyatt
Sent: Monday, May 26, 2008 9:53 PM
To: Miata Power List; Miata Mailing List
Subject: Re: '02 Miata Bucking Without CEL - Big Mystery!
 




It's worth noting that this happened with the tank about 1/2 to 3/4 full.  Is there any way to clear out the condensation?  Some sort of alcohol-based solution?
 
-Bryan

--- On Mon, 5/26/08, Ray Ayala <ayala.ray at gmail.com> wrote:

From: Ray Ayala <ayala.ray at gmail.com>
Subject: Re: '02 Miata Bucking Without CEL - Big Mystery!
To: bryanewyatt at yahoo.com, "Miata Power List" <miatapower at miatapower.net>, "Miata Mailing List" <miata at realbig.com>
Date: Monday, May 26, 2008, 9:42 PM


My dad had that happen once and it turned out to be condensation in the fuel tank.  Apparently a few small puddles of water will drift around on the bottom of the tank and part of one will occasionally get sucked up by the fuel pump.

 

 


----- Original Message ----- 

From: Bryan Wyatt 

To: Miata Power List ; Miata Mailing List 

Sent: Monday, May 26, 2008 4:41 PM

Subject: '02 Miata Bucking Without CEL - Big Mystery!

 




All,
 
I'm not sure how to describe this in one word, but here goes the long version:
I was on my way home driving across Ohio this weekend and 3 separate times the car (an '02 with stock everything intake/exhaust/ignition and about 60k on the clock) began to buck uncontrollably.  The revs would bounce within a 500rpm range of whatever value they were at when the car began to buck.  The only way to "cure" the problem was to turn the car off and wait for it to cool down.  Unforutnately, the car didn't always start on the first try.  Very frustrating!
 
As I said before, the car is stock everything (I even put on a stock exhaust after I bought it).  I replaced the plugs about a month (and 1000mi) ago, but the car did this same thing on the old plugs.  It will even repeat the behavoir at random in the parking lot at work driving at no more than 25mph.
 
Any ideas?  Could heat soak be affecting the coils or wires?  Maybe even the Cam Angle Sensor?  The car seems to start up after I let the engine cool.  Is there a way I could effectively cool off the engine bay?
 
To repeat one last time...the car does not throw a CEL even after the car is restarted.
 
Thanks for your help!
 
-Bryan and The Tick
 



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