Searched for other similar problems -- all of which seem to refer back to the EGR valve. But before attempting to replace this valve i wanted to post my Exact problem and see if any other insights may be available.

At 750 RPM it idles rough, it will fall to 450-500 rpm and when that happens the engine shakes/misses and shuts off. Occasionally but not all the time, it will idle up over a 1000 rpm for a second or two then drops back down again.

I have cleaned the MAP sensor, checked vac hose leaks (none found),

Runs well when moving and idle up around 1000 rpm, but at a stop or even when slowing down, once the rpm drops below 500-700 rpm it runs very rough and sometimes just shuts off.

Please Help!

Thanks in advance.

 

Larry:
before you spend money on parts, how about pulling the throttle body and the EGR valve and cleaning them together with the IAC valve. While the throttle body is off you can also find the orifices for the EGR. In my 98 Protege they are at the opening of the intake manifold at the 6 o'clock and 12 o'clock positions.
Use only TB cleaner on the TB.
The EGR ports, passages and valve can stand something stronger like B12 Chem tool.
Get a new gasket for the EGR valve.

Also there is a vacuum hose that connects the EGR Boost sensor to the intake manifold. Find it pull it off behind the IM and poke in there with a strong wire. If you feel resistance push through.

These measures should help stabilizing your idle.

If your plugs and wires are old replace them. If you are using 87 octane fuel switch to 89 octane.

 

Thank you for the prompt reply tanprotege

This is exactly the info i was looking for. Alternatives to replacing the egr. It may come to that anyway, but i wanted to make sure i'd covered all the other bases first. The other similar threads mentioned the usual suspects but this is the first one i recall seeing that references the orifices of the egr *and* using only TB cleaner (if i'd sen them i'd have used B12 chem as it has been referenced many times as a cleaner).

Again, i DO appreciate your help (i've seen your helpful posts all over this forum so many many kudos 2U).

I'll let the forum know how things work out. Many thanks again.

Larry

 

You are welcome, Larry.

Many throttle bodies have a coating that makes it less sticky for dirt. If you use the wrong cleaner the coating gets washed off. I like using dedicated CRC brand products.

BTW this sticky is for the Protege but most of it applies to your 626 as well:

https://www.mazdaforum.com/forum/maz...%E9g%E9-31136/