I have the 1.6L DOHC non-turbo four cylinder in my 1994 Mercury Capri and it idles at 2000rpm on cold startup. Where do I start looking? Thank you.

 

umm a merc on a mazda forum, well a car is a car, anyway its supposed to idle that high when its warm, now if it stays that high after the temp gauge reaches the middle THEN you have a problem

 

When I start my engine, and it's cold, it idles around 2500 and makes its way down.

 

My reason for posting this vehicle is that during its production run from 1989-1994 it was powered by both the non-turbo and turbo version of the 1.6L DOHC four cylinder MAZDA engine and transmission. Mine is the 5-speed. My "problem" is that it idles at 2000 rpm on cold start and is now remaining there even after reaching normal operating temperature. I restore Chrysler Convertibles for a hobby and Im not familiar with Ford/Mazda sensor systems. I was thinking it may be a faulty coolant sensor. I can find no vacuum leaks. I have not attempted to retrieve any fault codes either. Anyone have experienced this problem with this engine? It has to be a simple fix unless it requires O2 or MAF replacement. Anyone? Thanks.

 

wouldnt know but it sounds like you have the protege motor, mazda and ford dont mix, so even though its a mazda built motor, it still it built with the dimensions and sensors ford makes. i can guess that it may be your maf, iat, ect, or thermostat, the o2 sensor is going to determine if your mix is lean or rich but not control your idle if its up to temp

 

Finally found the high idle problem! There were two bolts missing from the airbox that were creating a vacuum loss. New bolts...better idle (850 rpm) Thanks all for your replies.

 

heh its always the simple stuff

 

Yeah,
So easy to overthink sometimes! Thanks.