I've got a strange problem with my car. I've got a 2007 speed3 with 54k on it. At about 50k,when I would start the car,it would do one of three things. One, it would start fine. Two, it would start but, you had to crank it over for about 4 or 5 seconds before it would start. Third, it would crank with a rough idle,then smooth out. I did a complete tune up including new denso iridium plugs. Nothing helped. Took it to the dealership twice. They said I needed an AEM airflow straightener for my MSCAI. That didn't help. They found the egr valve sticking open & the back of the throttle plate dirty. The cleaned both of those and it ran fine for about a day. Then the tech line said it was my MSCAI and they wouldn't work on it anymore until I put the factory air box back on. I did that and took it back to the dealer. No luck again. I found a dealer in Birmingham, Alabama that said they were aware of the problem in MS3 and MS6. I took it down there so they could do a intake and combustion chamber cleaning. It was amazing the amount of black carbon that came out of the tail pipe. It made the problem less frequent, but it still randomly starts rough and/or takes longer than normal to start. Any ideas?
Intermittent Hard Start
- Thread starter tfarmer69
- Start date
blackdragon0731
Member
- :
- 2008 Mazdaspeed3 Grand Touring - Black Mica
Does it idle rough after a full fuel up? Might be your purge valve if its doing that. That's what my issue was!
First point: Check the gap on your plugs. This is probably not your problem, but it's easy to do. Make sure that you gapped those plugs at .030. Don't assume they came properly gapped.
Second point: EGR valve may actually be defective, or it may just not have been cleaned well enough. See # 3 below.
Third point: If the cleaning helped but only for a day or so, I think it was not done well enough. Consider doing your own Sea Foam treatment. There are other threads here on how to do it. You do not put it into the fuel system, because our high pressure DISI system and close to 2000 psi injector spray is not Sea Foam friendly. Check the thread by Darth on this for how to do it properly. Also, if Sea Foam does not get the job done there is an excellent "how to" on another forum. I can't cross post to it under our rules but if you go to the mazdaspeed forum you will find a thread called: "How-To clean your 1st Gen Mazdaspeed 3 EGR." BTW, if it is totally stuck and blocked you should be getting a check engine light code P0401.
There is also a similar new thread here on your issue:
http://www.mazdas247.com/forum/showthread.php?123788848-CEL-help-Code-P0401
Finally, just almost as an afterthought, but worth considering: Have you checked the fuel filter? At your mileage it might need replacing anyway.
Last edited:
Darth Vader
Member
The fuel filter is a drop the tank, pull the fuel pump assembly, disassemble the assembly to check/replace. The in tank only has to prime the main engine-driven pump. Likely cause of this symptom alone? No. You'd see high rpm power die off first. Starting and idling takes only a tiny amount of fuel comparatively.
Quicky on Seafoam: undo the blue clip on the hose going down the front of the engine, in front of the intake manifold. This is the easiest way to suck Seafoam into the engine, a bit at a time, for about 1/2 of the can, then flood out the engine to stall it with the remaining bit in the can. Let sit for 20 minutes or so then, start it up and watch how fast your neighbours call FD.
Quicky on Seafoam: undo the blue clip on the hose going down the front of the engine, in front of the intake manifold. This is the easiest way to suck Seafoam into the engine, a bit at a time, for about 1/2 of the can, then flood out the engine to stall it with the remaining bit in the can. Let sit for 20 minutes or so then, start it up and watch how fast your neighbours call FD.
Thanks, Darth. I was stupid about the fuel filter location being in the tank with the low pressure pump. Agree, that there should be high speed starvation if that is the problem.
I remembered your thread on Sea Foam application technique and am glad you jumped into this thread with your sage advice. Hopefully OP can get his problem solved.
I remembered your thread on Sea Foam application technique and am glad you jumped into this thread with your sage advice. Hopefully OP can get his problem solved.
It's surprising to me that the dealer cleaned it instead of replacing it. I cleaned mine, but did not clean out the recirc tube nor did I do the sea foam treatment. Maybe they didn't clean out that tube either (metal tube that goes from EGR to intake mani. I'll be taking mine apart again soon to redo and complete the job.
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- 06 LS MS6
07 BM GT (shell has been struck from the roll)
thats interesting,
what controls the fuel rail pressure between keyturn and actual engine start.................
fuel pump actuator, if you've ever noticed there is a whine when you turn off the car that's the system pressuring up so next time when you turn the key it's "primed" and pressure is ready to go. Or you can always just turn the key to ON position and see if you hear the whine as well.
I believe that whine is the electric motor circulating coolant. I had the same system on my Lotus M100 Elan. It keeps oil from cooking in the turbo bearings.
The one fp on this car starts pressurizing when you turn the key. The cam driven high pressure pump is pressurized when the motor turns over.
The one fp on this car starts pressurizing when you turn the key. The cam driven high pressure pump is pressurized when the motor turns over.
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