Low Boost and check engine Light

[aceblaster]

Also, does anyone else seem to have a rough start-up? When I start my car it seems to be really harsh, lots of engine movement and possibly a misfire?

 

[joelgas]

Also, does anyone else seem to have a rough start-up? When I start my car it seems to be really harsh, lots of engine movement and possibly a misfire?

I had the same exact thing happen when my air intake temp sensor went out. Not saying that this is your issue, but all of your symptoms are sounding very familiar.

 

[aceblaster]

I had the same exact thing happen when my air intake temp sensor went out. Not saying that this is your issue, but all of your symptoms are sounding very familiar.

Where is that sensor located? Do you know of a way to test it to see if it is bad or just replace it? And did you have to go to Mazda directly to get the sensor?

 

[aceblaster]

I had the same exact thing happen when my air intake temp sensor went out. Not saying that this is your issue, but all of your symptoms are sounding very familiar.

Where is that sensor located? Do you know of a way to test it to see if it is bad or just replace it? And did you have to go to Mazda directly to get the sensor?

 

[joelgas]

Where is that sensor located? Do you know of a way to test it to see if it is bad or just replace it? And did you have to go to Mazda directly to get the sensor?

This happened to me on a Saturn I owned. I'm not sure where ours is located. I think that it actually may be incorporated with the MAF sensor.

 

[aceblaster]

This happened to me on a Saturn I owned. I'm not sure where ours is located. I think that it actually may be incorporated with the MAF sensor.

Alright, well I'll see if I can locate someone near me to switch MAF sensors with to see if that is it.

 

[aceblaster]

Another question. Every time I turn my key to the on position the fuel pump primes for a few seconds, immediately after the pump stops, if I turn the key off and back on, the pump prims again. If i keep doing this repeatedly the pump runs every single time, I know that with any other fuel injected vehicle, even if it is direct injection, the pump will only prime once every 60 seconds or so if the key is turned on and off without starting the engine. I'm curious, do all mazda speed 3 fuel systems act like this??

 

[Darth Vader]

I don't hear the in-tank prime but once if I don't start the car, just solenoids clicking and binging key-in chimes(shrug)

DI cars run mechanical fuel pumps that are lubed by the fuel in them. They HAVE to be full of fuel for sure right away. That's what the in-tank does.

 

[oaklandopen]

the MAF is actually a dual sensor....MAF/IAT. and there is also a MAP sensor

 

[aceblaster]

Still trying to figure this out. I'll try and keep everyone posted on my findings. Feel free to throw out any more suggestions. Thanks for the info so far guys.

 

[oaklandopen]

Do you have the actual shop repair manual? You may just have to go right down the list of steps.

Or you'll have to bite the bullet and uninstall your mods one at a time and see which one may be giving you the problem, if a mod really is the problem

 

[aceblaster]

Do you have the actual shop repair manual? You may just have to go right down the list of steps.

Or you'll have to bite the bullet and uninstall your mods one at a time and see which one may be giving you the problem, if a mod really is the problem

Did the shop repair manual come with the car? I haven't bought any manuals for the car since I purchased it.

As far as the mods go, I'm fairly positive that the mods aren't a factor. I went about a month and a half (2500 miles) after my last mod before I started getting any CEL's or problems. I'm in the process of finding another local MS3 owner to help me troubleshoot some of the sensors and parts just in case though.

 

[oaklandopen]

I asked about the shop manual because I posted the list of possible problems and you said you went through them. I got that list from the over 2000 page shop manual (also contains regular 3)

Still, just cuz you don't think its a mod because its only been X amount of time doesn't mean something hasn't faied either on the part itself or as a result of the part. There are so many possible points of failure, it could be like going through a dictionary just to find out the zebra did it

 

[oaklandopen]

I had my cai on for a few months and few thousand miles, threw a code, and discovered some of the tubing came loose and had a leak. Lucky for me I got the code and found the problem right away upon a quick glance and wiggle test

 

[aceblaster]

I asked about the shop manual because I posted the list of possible problems and you said you went through them. I got that list from the over 2000 page shop manual (also contains regular 3)

Still, just cuz you don't think its a mod because its only been X amount of time doesn't mean something hasn't faied either on the part itself or as a result of the part. There are so many possible points of failure, it could be like going through a dictionary just to find out the zebra did it

The list you gave me I have went through about %70 of it. But like I mentioned before I'm trying to find someone in my area to troubleshoot the rest of the list with and with my aftermarket parts. I'm still planning on checking them out, I was just throwing out there that I think it's something else. But I'm still going to check it out.

 

[oaklandopen]

Okey dokey. This shop manual would be cooler if it was only for the speed, and if I were to print it out since adobe blows

 

[aceblaster]

I wanted to cross something off my list of To-Do's today so I pulled off the FMIC pipe that connects to the throttle body.
1st- I cleaned out the throttle body just in case it was getting stuck.
2nd- took off my BOV and resealed the Gasket.
3rd- when through all my couplers on my FMIC and made sure everything was tight.
4th- checked hoses going to the Boost control solenoid/wastgate.
5th- Reset the ECU

Now I'm just waiting to see if the CEL comes back.
The Gasket on my BOV was pretty beat up so I'm hoping that was the problem. When I sprayed Carb cleaner on it before it seemed ok but I only physically inspected the top of the BOV.
I'll post up once the CEL comes back or I decide it's not going to come back.(cross fingers)

 

[oaklandopen]

Carb cleaner on the bpv gasket? I might have used a little touch of grease instead

 

[focoms3]

If your throwing a CEL with too lean of conditions have you ever thought that the problem was your fuel pump? They had an issue with some earlier '07 speed 3's and actually changed the fuel pump design, although your car is an 08.5 this might not be the case.

But the ECU would definitely turn down the boost if it wasn't getting enough fuel pressure. I'm going through a similar problem, don't have a dashhawk to actually check my #'s but it's going in to dealer next week.

 

[joelgas]

If your throwing a CEL with too lean of conditions have you ever thought that the problem was your fuel pump? They had an issue with some earlier '07 speed 3's and actually changed the fuel pump design, although your car is an 08.5 this might not be the case.

But the ECU would definitely turn down the boost if it wasn't getting enough fuel pressure. I'm going through a similar problem, don't have a dashhawk to actually check my #'s but it's going in to dealer next week.

That may explain possibly why the fuel pump keeps engaging after he turns the key on and off. Maybe its not generating enough fuel pressure.