Greetings,

Some of you know all the work I've put into my car in the past 7-months and I've come a long way and really appreciate the help I've gotten here.

The car is about done now, but I'm having a problem with the idle. I adjusted the throttle cable, and later was told that the idle is set at the factory and the cable should NEVER be adjusted.

Here is how the car acts now. Has a bit of a high idle when I start it. but the CEL is not on and it drives alright. After driving for a while though, when I get to a stop sign the idle drops down about 500rpms and the CEL comes on. When I start off from a stop and give it gas the CEL goes off, and it does hessitate a bit when coming off a dead stop. When I take my foot off the gas now the CEL comes on, but then goes off again when I'l accelerating. When I park it after driving for a half hour or so, the idle drops down to 500/400rpm. The car is a '94 Mazda MX-3 GLS 6 cylinder Automatic.

So how do I fix this and do I need to get some kind of gauge from Autozone to do it? This is the last think I have to do to this car. I'm really excited about my car running well again.

Thanks again for all that have helped me. I have learned a great deal about my car, and have really enjoyed working on it.

 

It does sound like a vac leak.
When you are at a stop i want you to try something different.
You see, a similar thing happened to me at stops. It was the vac brake booster that was faulty.
So next time you are at a stop, i want to to get your foot off the brake pedal and apply the parking brake. The parking brake is mechanical and not vac controlled like the brake booster. You may also try putting it into neutral as well.
If it only happens at a stop it could be the brake booster or a different vac leak
OR as the engine isn't revving hi enough the vac leak can actually affect a rough idle, and when engine revs higher the small vac leak has no overall affect in as there is more air flow.
You may also clean your throttle body.

 

Hey BengalBrad! Good to hear from you.

Noggin is giving you some sage advise. Now the brake booster and booster hose are not the only possible sources for tiny vacuum leaks. It is also possible that another issue is causing you almost dying idle. In fact I have experienced the same with the '98 Protege. It is solved now but I don't know what exactly solved it. Please read my "Unofficial User's Guide to the 95-98 Mazda Protege". It is a sticky thread in the "Protege Forum".
(If you like the guide you may give it a yellow star or two).
Cleaning the whole intake system, the EGR system, and in particular the Idle Air Control Valve are things that contributed to fixing the issue.

 

just one question: when you adjusted the idle, was the engine in operating temperature? remember, after the engine warms up, the Intake Air Control valve (IAC) will lower the engine revs, and also compensate for when the AC compressor kicks in. to make things more interesting, there is an air valve that works only when the engine is cold. if you have no vacuum leaks, make sure the idle is adjusted at engine operating temp. the idle is always a little higher when cold and go down when warm. the idle should be at around 750 rpm, 650-750 rpm. another note. if problems persists, look at the throttle position sensor. it might need a little adjustment. of course, make sure you dont have any vacuum leaks.

 

Ok, so I decided to work on the timing. I thought I found the "one" screw to loosen the distributor cap, however, I had bang on the distributor cap to get it to move.....It never did. I did something to the distributor cap, there is an electrical connect on top that I believe I cracked.



Here is a pic of the cap, can someone please let me know how to rotate it?

The car doesn't start now. I did bang with a rubber mallet on the top of distributor cap on the electrical connection at top of Distributor Cap. The car was running while I did this, while I was hitting the top of the side of the the car it stopped running I get zero codes when I do the paperclip test. I am stumped here, can someone give me an idea of what is going on?

 

Did you check if there is a second bolt?
I suppose the distributor could be stuck caused by corrosion. You could try WD 40 at the base or use a oil filter wrench around the metal base for leverage.
One of the best penetrating concoctions is acetone and tranny fluid 1:1. The acetone penetrates and takes the tranny fluid along.
It sounds like you need a new cap.

 

Yeah, there is a second bolt, it's at the bottom of the distributor assembly. What I have seen and read said there was only one bolt and I found that and loosened it. It is a new distributor cap. I took a rubber mallet to the top right side of the distributor assembly; actually it is a black electrical connector that was the only thing I could find to hit with the hammer. See Picture. i gave this a good whack and the car died. The distributor cap DID NOT MOVE. The car cranks now, lights/radio come on, so it's not battery. Also, when the car died the pos cable on the battery jumped off the terminal..... so there must have been a surge of some sort. The main fuse is also fine.

I get no CEL... I am stumped here

 

for the picture, it looks like the distributor cap for a 6 cylinder engine. i did not know the 1994 mx3 had a 6 cyl engine. if it is a 4 cylinder, it has 2 bolts. here a picture of the part.

 

Juanky: The 6 cylinder was an option. It has 1.8 L of displacement. The 4 cylinder has 1.6 L and it is the same as in the 323. BengalBrad is referring to the bolts at the distributor base, not the cap.

BengalBrad: The picture does not show the connector well enough. But you may want to look if an individual pin or wire has been damaged/ bent. You may be able to jury-rig the connection.

I think you don't get a code because the damage occurred when the engine went off. Therefore the computer did not receive enough data. Go and check for spark. I bet you don't have any and the reason is the damaged connector.

 

ok. there is always something new to learn! thank you tankprotege,
i stand corrected.