Drops to low idle after boost

[BOOSTR]

Have you pulled the spark plugs to see how they look? If they are the originals, changing them along with the pcv will help with your dipping rpm issue. That CEL has nothing to do with your rpms.

I've never cleaned my egr nor do I intend to. I do get that cel on occassion(even with the antifouler setup) and simply remove the 2nd O2 sensor and clean it with electronics cleaner or brake cleaner. That works everytime. I'm not replacing a sensor that serves no function other than to annoy me with a cel on occassion.

My advice to you is to go to the nearest Advanced Auto and pick up 4-NGK stock #4291 plugs, a can of Seafoam and a Purolator PV 1047 pcv. (check that number its for a Mazda Milennia supercharged)

 

[Flspeed]

Ok, i will give that a try this week.

 

[Flspeed]

This droping idle issue is getting worse. Now the idle will drop when I give it gas when the car is not in motion. Today I did the non fouler fix and refitted all the vac line. WTF is the problem(argh).

 

[Flspeed]

I think I might be getting somewhere. I found that the hose going to the wastegate was loose and did not have a clamp on it. So I put a clamp on it and ran it. The idle problem seems to be gone, but now I noticed that when I hit about 4200-4500 rpms it feels like boost cut. I dont have a gauge in there yet so I cant see what is really going on but it feels like I am hitting ppeak boost.(dunno)

 

[Spooler]

What do you mean by boost cut? Do you suddenly loose all power (my car had that, boost leak) or your car doesn't seem to boost as usual? In either case, I would look for a boost leak. Soappy water or a pressure test.

 

[Flspeed]

I took it out to see how it spools and right around 4200 rpm I heard what sounds like the boost is leaking back through the BPV. Is this possible?

 

[speednv]

well mazda has a re flash for the pcm for that concern so take it to the dealer and have them reprogram the pcm it will cost you about $100 but it should get rid of most of that boost drop problem... mine was doin the same thing until i reprogramed it

 

[Flspeed]

Now things have changed yet again. This morning I didnt notice the boost issue at all but it was cool out so I dont know. The idle drop problem is back. But it definitely was when the car car good and warm.

 

[Spooler]

Heat soak is pretty harsh too on hot days or when you're stock in traffic for a while

 

[Flspeed]

Well I put my car in the Mazda shop agian today and still got nothing accomplished. They reset the idle and chargd me $105 and it did exactly nothgin. The car still wants to stall when I give it gas and try to let it settle out. Of course they said that was all they could do with no cat which is bull%$#@. They said there was no updates for the pcm and that the short ram intake could be casuing problems. I am going to get some new plugs and look into a new intake this weekend. I am thinking of doing the sea foam thing but dont really know anything about it. Is it a safe product to use? What should I do to my car to prepare and run the sea foam. Any help on this would be appreciated. Thanks.

 

[BOOSTR]

Seafoam requires no prep, just take the hose off the pcv and pour 1/3 of the bottle into the hose. Works great when you use a small funnel in the hose. Turn off the engine and restart after 5 minutes. Definitely change your plugs as I said previously. Old plugs and clogged pcv will cause idle issues. What is your vacuum reading at idle?

 

[Flspeed]

I dont know about the vac at idle. I dont have a gauge setup yet. I have an old sunpro gauge I might use for right now.

 

[Flspeed]

Well I did the sea foam, new PCV, new NGK platiniums, and it still has the same dropping idle problem. It seems like the throtle response is a little sluggish too. I dont know if its all connected to the same issue. Now Im up for any ideas. Please.

 

[Flspeed]

Anybody have any ideas?

 

[Flspeed]

I put a new EGR in today and cleaned the MAF. The idle problem still exist. I cant figure this out. It is only when the the motor is heated up. What would cause problems when heated?

 

[Flspeed]

Today I refitted all the vac hoses and I found a old boost/vac gauge so I plumed it in. I am getting between 20 and 25 in. of vac at idle. When the idle drop comes in the vacuum drops to about 15 in. then makes its way back up to 25ish. I also noticed I am only running about 5psi of boost. Is this normal for these MSP's?

 

[Spooler]

Mine idles at 23 in. and boosts 6.5 psi. All I have on my car is a K&N drop in

 

[Flspeed]

Is the wastegate adjustable at all?

 

[ruskeyjdm]

I got the same problem, i cleaned my egr and changed my plugs. Im running about 27-28 in. at idle. Still idleing low after boost....

 

[y0sky]

try replacing the bpv it sounds like it could be leaking