91 Miata 1.6L (Short nose, good keyway)
Will not keep a steady rev under constant load. In the Video, the throttle is being held at around 10%, and you can see the cable is not moving- but the engine dips and revs by itself. Does this cold or hot.
- Idles fine
- Runs to Redline fine
- Not down on power
- No engine codes
What we have done-
-New Coil Pack (tested good)
-New Timing belt +pulleys (double checked)
-New AFM (MAF) (Tried 2 others from running cars as well)
-New Plugs/wires
-Checked for Vacuum leaks (cant find anything)
-New Fuel Pressure Regulator
-New Fuel Filter
-Ran Injector cleaner
What could it be?
Ecu? CAS? Something else?
http://www.youtube.com/watch?feature...&v=XXtHwdUbba4
91 Miata Engine trouble...
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91 Miata Engine trouble...
Brock Clayton
92 Miata - Turbo
93 Miata LE #466/1500
83 RX7 (in theory)
92 Miata - Turbo
93 Miata LE #466/1500
83 RX7 (in theory)
- n33d4sp33d13
- Seasoned Autoxer
- Posts: 650
- Joined: Thu Apr 15, 2010 9:07 pm
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Re: 91 Miata Engine trouble...
i had sorta this same problem in the colt and unfortunatly never really figured it out till the engine was rebuilt. i know my car has a idle air control valve (probably called something different on a miata) that i have tinkered with that has fixed several issues i have had with idle and misfires. i always adjusted my idle with my cable but turns out i was supposed to adjust the timing then adjust the IAC then tighten the cable. if your car has a IAC or something like that it could be that. i know the only similarities a miata and a colt have r they are both japanese but you never know. did you check the timing?
Steffen Clark
#13
White/Orange 1991 Mazda Miata ITA/ STL
Dark grey 2014 Subaru WRX STI D Street
White 1984 Plymouth Colt Turbo SMF
1991 Mazda "hacked" Miata A Mod
Red 1984 Plymouth Colt Turbo
Red 2019 Toyota Tundra
#13
White/Orange 1991 Mazda Miata ITA/ STL
Dark grey 2014 Subaru WRX STI D Street
White 1984 Plymouth Colt Turbo SMF
1991 Mazda "hacked" Miata A Mod
Red 1984 Plymouth Colt Turbo
Red 2019 Toyota Tundra
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- Veteran
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- How many miles is the Indy 500 times 2?: 1000
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- Location: Christiansburg, VA
Re: 91 Miata Engine trouble...
sounds like the frequency of the surges is increasing. Have you sprayed for vacuum leaks w/ carb cleaner or similar? Also, does it exhibit the same behavior at any rpm?
-Henry Lehmann
BRR Solo Chair, Treasurer, and Equipment Steward
"If you want to get it done, you have to do it yourself."
BRR Solo Chair, Treasurer, and Equipment Steward
"If you want to get it done, you have to do it yourself."
-
- Pylons are afraid of me!
- Posts: 392
- Joined: Tue Jun 07, 2005 1:26 pm
- How many miles is the Indy 500 times 2?: 1000
- Competition Car: Miata
- Location: Blacksburg, Va
- Contact:
Re: 91 Miata Engine trouble...
It was a faulty Throttle position Sensor. FIXED!
Brock Clayton
92 Miata - Turbo
93 Miata LE #466/1500
83 RX7 (in theory)
92 Miata - Turbo
93 Miata LE #466/1500
83 RX7 (in theory)
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