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Cold start problems
Posted: Mon May 01, 2006 9:53 pm
by EGG80X
I noticed recently the engine hesitates to accelerates below 3500rpm on cold starts once its warms up its fine....... also still having idle dip when the engine is cold too grrrrr
Posted: Mon May 01, 2006 10:24 pm
by fig
Join the club!
Where are all the so-called experts when you need 'em
Someone must know of a solution?????
Posted: Tue May 02, 2006 10:00 am
by Garry
I fixed my idle dip by cleaning the air bypass passage. Both my MX5's ran like crap when they were cold on light throttle low RPM. Quite normal according to several Mazda Dealers. Though replacing the oxygen sensor helped my SP considerably.
Posted: Tue May 09, 2006 3:04 pm
by DanielB
My NA 1.6 experiences this too. On a cold start, if i bring the revs to say, 3,000 and hold the throttle there, it will slowly dip down to say, 1,500 then climb back up, and does this over and over until the car is warm
No idea what the cause of this is. New plugs/leads does nothing.. It feels as though the car is only running on 3 cylinders when it's doing the above.
Posted: Tue May 09, 2006 4:06 pm
by Andrew
You guys tried this -
Matty wrote:I'd be guessing contamination of the throttle body - either clean it, or adjust the bypass screw.
Posted: Tue May 09, 2006 4:14 pm
by JBT
Be careful what you use to clean the throttle body because it can be damaged with the wrong solvent. See miata.net garage or search that forum for more info. Also see the post
here by Fra66L.
Re:
Posted: Tue May 09, 2006 4:16 pm
by Craig
DanielB wrote:My NA 1.6 experiences this too. On a cold start, if i bring the revs to say, 3,000 and hold the throttle there, it will slowly dip down to say, 1,500 then climb back up, and does this over and over until the car is warm
No idea what the cause of this is. New plugs/leads does nothing.. It feels as though the car is only running on 3 cylinders when it's doing the above.
Crappy running whilst cold and OK when hot is usually attributed to the Oxygen Sensor. It can't get a reading so it goes into a limp mode.
Re:
Posted: Tue May 09, 2006 4:17 pm
by Andrew
JBT wrote:Be careful what you use to clean the throttle body because it can be damaged with the wrong solvent. See miata.net garage or search that forum for more info. Also see the post
here by Fra66L.
Here is his post to stop any confusion -
Fra66L wrote:Normal NB8A problem.
Try taking off theintae crossover tube and caefully cleaning the throttle body and butterfly plate with a VERY SOFT, CLEAN rag and some (oxygen sensor safe) carby/throttle body cleaner (pressure pack can). I do this every oil change and it pretty much eliminates the problem.
The throttle clearances at idle are marginal and once you have a nice coating of Ick (technical term) thanks to EGR and PCV, the clearance is worse so a regular clean keeps things happy...
Cheers,
T