I have a Mazda Miata,2000. It stumbles and occasionally misses on acceleration,just off idle. I have replaced timing belt,spark plugs,plug wires,coil packs,catalytic convertor,upstream and downstream O2 sensors. what can be causing the stumble and miss?
Asked by migration_wallyHD Jun 14, 2015 at 07:52 AM about the 2000 Mazda MX-5 Miata SE
Question type: Maintenance & Repair
initially,the car missed and brought up a code for an engine miss. I replaced spark plugs,wires,and coil packs,since all were original. the miss continued,excess gas in cat convertor damaged the convertor. I replaced it and both O2 sensors. there is no OBDII code showing now,yet,but a stumble and miss on acceleration just as I leave idle or low engine speed causes loss of power
12 Answers
firebird338 answered 9 years ago
Did you replace air filter and clean throttle body and change fuel filter if have not done so in a while ?
migration_wallyHD answered 9 years ago
new air filter,new fuel filter,sprayed throttle body. If anything,the stumble/miss is more pronounced. I had to disturb the throttle position sensor to clean the throttle body. maybe that is the problem??
firebird338 answered 9 years ago
Put in some fuel injection cleaner in gas tank.
migration_wallyHD answered 9 years ago
the stumble became more frequent and pronounced after i sprayed the throttle body. I removed TB,took throttle position sensor off to isolate it from the spray. whatever it is,it is getting worse
firebird338 answered 9 years ago
Clean throttle body again but this time use a old tooth brush to clean inside of throttle body while holding open choke and also use a micro fiber cloth and wipe the place were the choke sets when it is closed.
migration_wallyHD answered 9 years ago
I cleaned TB again,per your advice. when i went to restart car,battery died. low voltage may be the culprit. i doubt I'll find a battery for a Miata on Sunday
Have you checked your idle control valve or idle air control located under the throttle body they tend to cause stalling, irratic idle, and idle droop on decel.
migration_wallyHD answered 9 years ago
going away on vacation;will get back with you guys next week. thanks!
migration_wallyHD answered 9 years ago
I removed the IAC,sprayed it with cleaner. I had done this with success on Ford 3.0 V6 engines. it made no difference. the problem is getting worse. I discovered a dead cell in the battery,installed a new one. sometimes low voltage affects electronics,but it made no difference. The car stumbles on rapid acceleration,misses,especially coming off low RPMs. I checked the wiring connections to the camshaft position sensor also
firebird338 answered 9 years ago
Have your fuel injectors tested may have bad injector is injectors.