2003.5 Stalling when downshifting, rough idle

[Syonix]

This is the car that keeps on giving gifts! By gifts I mean problems.. lol. One after another ..

Just replaced my LSD, a new clutch assembly, belts and a water pump..


The car has a very rough idling and dips down and stalls after you've been driving it when you downshift or stop at a light. I have to feather the gas in order to keep the car from stalling. It doesn't always seem to occur and if I baby the rpms down then I can sometimes get it to not stall. Recently its starting stalling when i downshift as i pull into my parking lot. The car dies turning a corner going from 2 into 1 and I have to turn it back on quickly in order to make the turn..

I've cleaned my EGR valve recently and it didn't appear bad at all.

the car did just hit 100k, I've had it since 27k and never had it replaced.

 

[littlemimus]

This is the car that keeps on giving gifts! By gifts I mean problems.. lol. One after another ..

Just replaced my LSD, a new clutch assembly, belts and a water pump..


The car has a very rough idling and dips down and stalls after you've been driving it when you downshift or stop at a light. I have to feather the gas in order to keep the car from stalling. It doesn't always seem to occur and if I baby the rpms down then I can sometimes get it to not stall. Recently its starting stalling when i downshift as i pull into my parking lot. The car dies turning a corner going from 2 into 1 and I have to turn it back on quickly in order to make the turn..

I've cleaned my EGR valve recently and it didn't appear bad at all.

the car did just hit 100k, I've had it since 27k and never had it replaced.

get the cdm one.

 

[pavone]

any mods to the car?

 

[mazdaspeedp]

ya get cdn egr, replace wastegate with one from atp,and check ur exhaust manifold for cracks and broken bolts

 

[Syonix]

ya get cdn egr, replace wastegate with one from atp,and check ur exhaust manifold for cracks and broken bolts

Thanks,
You guys got links to the parts?

 

[MSP-2003.5]

I may be way off, but if you have stock intercooler piping, check the nipple on hot pipe and see if it is broke or cracked

 

[Wildfyre]

Yeah, sounds like a large boost leak to me. Have you double checked every connection that you took off from your last set of repairs? I'd check for boost leaks before throwing money at it replacing parts that *might* not need replacing.

 

[justanothermp5]

do you have a blow off valve?

 

[msp727]

it could be you IACV ( idle air control valve) or if you have a BOV that could be bad cause my car does the same thing all the time but i think its my BOV cause at idle air seeps out of it so i think my BOV is bad.... so cheack those also

 

[Laser Blue]

Since I put my car back to stock its doing the exact same thing. It will start and will idle perfectly in the driveway, but there is noticeable hesitation when I first start moving from a stop and when I slow down to stop the idle drops hard. Sometimes it catches itself and hops back up to about 700 rpms and then settles to about 550 and idles normally. Other times it just dies, but when I restart it, it again idles normally. When I'm going through the gears it runs fine and goes in and out of boost normally.
The other thing is that I still have my wideband and boost/vac gauges in place and the vac reads 24 at idle just like before. Could I have a leak that affects performance like that without it showing up on the wideband or is it something else?

 

[CHIQLES]

no its the maf location, if theres any type of leak it will do all thoughs symptoms even at stock location. I got 80,000 on mine and tried going back to stocker style but I had all thoughs same issues. so I just moved the maf back closer to the throttle.another issue is which people may not relize is that if you increase the volume on the pipes the throttle has more air volume to pull from before the maf senses anything getting drawn.
so if you have hard pipes there usally 2.5. I got a combination of the two running on my car hot pipe 2.25 cold pipe 2.5. I also have the aem intake which i think is 3 but may be wrong.

 

[msp727]

CHIQOLES is right i just relocated my maf closer to my throttle body and it runs alot smoother and it does not stall anymore. also the idle is perfect so all you got to do to solve this problem is relocate the maf good luck...

 

[Laser Blue]

I'm talking about the bone stock intake setup...
My car ran fine with my aftermarket intake, smic, hardpipes, RDV, etc. but I took all that off and put stock plastic intake box, stock pipes, stock BPV, etc on the car. The MAF is exactly where it was put when the car was built by Mazda. So what is causing my car to run so erratically when decelerating and coming to a stop?

 

[b_dues]

This is interesting. I have the same problem that both of you have. I am going to look at moving my MAF to the hot side and see if that works.

 

[CHIQLES]

You want it on the cold pipe not the hot one and make sure it's after your bypass/bov or you will still get the stalling while shifting down.

 

[NEWBMAZDA]

so the hesitation and stalling is because of the MAF? I also have the same problem as syonix. My MSP hesitates a lot and it sometimes stall when at a stop light or slowing down. I have to press the gas pedal a bit so it wont turn off. I was thinking it could be the my BVP or the WGA

 

[b_dues]

You want it on the cold pipe not the hot one and make sure it's after your bypass/bov or you will still get the stalling while shifting down.

I don't think you are correct. A lot of people are saying to move it to the hot side now. I think the cold side is old news, although mine is on the cold side because it does not seem possible for me to mount mine on the hot side.