I have a 2001 1.6L Protege with low idle. When Im in DRIVE and parked at a light or stop the idle is around 200-300, the car shakes a little. Sometimes drops to 150 or so.
In PARK its at 500 tops, when its supposed to be 800 to 700.
Any ideas on what may be causing it? Faulty Sensor? Or a vacuum leak?

Car has 45k on it, good condition. Fluids changed regurarly.

Any help would be appreciated.

 

welcome to the forum. First things first..

is all of your scheduled maintaince up to speed?

when was your last tune up?

when did you last change your air filter?

do you have any check engine lights or error codes?

are you using good fresh gas (not stale)?

have you had your Fuel injection system cleaned?

when did you last replace your fuel filter?

When did you last clean your throttlebody?

How does the car drive normally? up hills? coasting? on the interstate?



Vaccuum leak is a big possibility but it' hard to diagnose that over the net. I'd check the other things I mentioned first.

 

EGR could be the culprit - would cause this...

 

Thx for all the replies.

The car is off lease, one owner and from what I can tell he kept up with the maitneance, don't know when the last tune up was, or the air filter changed but planning to go to the dealer to check the problem out. So far I have NO check engine light or error codes, using fresh gas, thinking of buying additives to clean the Fuel injection system. The car drives normally, no big struggles up or down the hill, no stalls (so far), drives fine on the highway, goes 3200rpm at about 110 to 120khm/hr . Just when its in Drive stopped or in PARK the idle is bellow what it should be.

I had this problem when i test drove the car, was at about 150 RPM needle bouncing up and down, they fixed it........untill the idle started to drop from over 800 to 200 over a period of a week. Im guessing they just increased the idle speed thinking it that should make it work fine. All fuels are relativley new, engine has a new baterry, will check on the status of the air filter.

What is an EGR?

 

i only know that "EGR" is a valve

i dont know what "EGR" exactly stands for though..

 

EGR is exhaust gas recirculation. It takes exhaust gases right out of the manifold and reintroduces a small fraction back in for combustion to help with emissions. Sometimes the valve gets a lot of gunk buildup and causes rough idlind.

 

Brought the car in to the shop. They took apart the EGR valve and checked all the sensors and the comp. Car now runs a tad smother but same idle speed on 300 in DRIVE when stopped and 500 in PARK. Dunno, might be normal for a 1.6L. Any ideas.

 

After I put my Rex away for the winter, I decided to turn my attention to my often disregarded Protege. It also had a similar low idle proble, in addition to an acceleration issues, especially in 1st gear -- I fixed both problems, took about 2-3 hours in total. The following may help.

1. Redo the timing, not sure what the factory setting is, but the timing is easy to advance (just 1 screw)

Over time, it looks like the wire that activates the throttle gets loose over time (this happened to mine).

2. Take off the Air Hose and clean out the throttle body

3. Change the PCV

4. Lubb throttle controls

Try the above and see if that helps.

I did this to my 99 protege (1.6L with 184K and it drives like new now).

Good luck

ps* if you want some other tips on getting the protege into tip top form, let me know.

 

After I put my Rex away for the winter, I decided to turn my attention to my often disregarded Protege. It also had a similar low idle proble, in addition to an acceleration issues, especially in 1st gear -- I fixed both problems, took about 2-3 hours in total. The following may help.

1. Redo the timing, not sure what the factory setting is, but the timing is easy to advance (just 1 screw)

Over time, it looks like the wire that activates the throttle gets loose over time (this happened to mine).

2. Take off the Air Hose and clean out the throttle body

3. Change the PCV

4. Lubb throttle controls

Try the above and see if that helps.

I did this to my 99 protege (1.6L with 184K and it drives like new now).

Good luck

ps* if you want some other tips on getting the protege into tip top form, let me know.

 

Can i adjust the timing on my P5 with just one screw? Please tell me how!

 

Yeah, that'd be nice. Too bad, though.
I didn't know you could do it on the 1.6!

 

We can't this is the first time Ive heard of it.
Everything is ecu controled, mazda would have to go out of there way to make a car that would void its warrenty at the turn of a screw. Would be pretty slick though.

He must mean adjust the idle or throttle screw or something like that.

 

I believe it is the throttle screw...anyways, did the suggestions help at all? I am by know means a "protege expert" but yes, the timing is controlled by the ECU (like everything in the car) however, there is still a manual component... at idle, adjusting the throttle screw will allow you to advance the rpms. Advancing the rpm's at idle should solve your poor idling.

 

Don't you have to adjust the throttle stop on the bracket?

???

And won't this still just mask a problem?

 

If you tighten the throttle screw and bring up the rpm's at idle, you have solved the problem...it's better than opening up the block to see if internals are damaged. I have a theory the throttle controls get loose over time....just my 2 cents.