mx5cartalk.com

Hi all. So today i went for fairly long drive, not constant. On the way home i was on the freeway for an hour, 1/2 an hour travelling at 110-115kmph. Exited freeway and came to a stop at lights. Went to take off and car wouldn't boost up, just surged and sort of stuttered. Was okay if I didn't put my foot into it. Not a hot day,26c. Parked up at a tavern for one cool one and then drove off 45 minutes later with no issue. Car is about due for service. Could this just be plugs or is heat soak an issue with the 2004 SE ( Stock). Thanks

What is done to it?

Totally stock Dann. Went for a 3.5 hour drive last weekend and car performed beautifully. First time it's bogged down like this. 104,000 k's. So last service was 11000 ks ago. I was going to use BKR7E-11 plugs. Does anybody else use and recommend these?

I think you're encountering "the bog". It affects all stock SE's eventually. It comes and goes, but once it starts coming, it comes more often.

When you move off from the lights or a stop, does it feel like it just doesn't want to run, like it bogs down almost stalls, and you have to give it some revs to move off?

Do a search on it on the old mazda-speed.com site (it's in archive mode now, no new posts but all the old stuff is still there). It comes down to a faulty solenoid over on the intake side of the engine with all the emissions stuff. I replaced mine with a 3 port MAC valve, worked perfectly.

ManiacLachy wrote:I think you're encountering "the bog". It affects all stock SE's eventually. It comes and goes, but once it starts coming, it comes more often.

Seconding 'the SE bog'.

There are a number of fixes available, mine went away when I replaced the ECU, intake and exhaust (funny, that!) - with the added benefit of MOAR POWR

So I'm guessing this is the valve your talking about. Now after researching people are using the ASCO 411L3212HV, small cylindrical solenoid. Is this the only one you can use as I do have a MAC35A-AAA-DDBA-1BA which is 12V. Can this be used instead of the ASCO? May pull out the valve and clean with some sparkies spray. Thanks

That's the sucker. Give cleaning it a go, it didn't work for me though. I also used the MAC valve like you listed.

When I moved to a standalone ECU I re-purposed it for boost control and put the old junk back in just to keep the circuit complete, but with the ECU it's not used.

Badbuzzard wrote:Is this the only one you can use as I do have a MAC35A-AAA-DDBA-1BA which is 12V. Can this be used instead of the ASCO?

Yup ... that's the one I used. If you already have one I wouldn't bother cleaning the old one the problem just recurs - change it over and fixed properly.

Sent from my SM-G930F using Tapatalk

So this MAC solenoid is ok even with OEM ECU, just thought people only used them with aftermarket ECU. Do I use the breather or block off and does Port 1 go to intake manifold or Port 2?

I know that it will change the boost by an amount which I cannot say. But people seem to have been using it on stock ecu and it works well enough for them.

Dann

It was fine, you aren't replacing the boost solenoid. I can't remember what it does exactly though. You just need it to direct the air properly, and right now the OEM part isn't switching when it's told.

Ok, so regards to configuration. Port 1 to inlet manifold? and the port 3,does the breather get attached or blocked off? And while I'm here, just been researching plus for the service. What was in there were Bosch Platinums Plus FR7DPX. Was going to use a NGK. Repco suggest BKR5E but I'm reading 6E and 7E-11's. FFS! can someone suggest one type and the gap it should be. I'll feeler gauge if need be.

I couldn't remember details, so I went hunting through my phone photos because I knew I took some. They would be in my build thread, but then Photobucket ruined all that.

Anyway I found them and I've pushed them to Imgur for prosperity (hopefully).


Basic setup of the solenoid


Rough orientation, you should be able to work out which hose goes where


I just used spade connectors crimped onto the wires so not to destroy any oem connectors

Couldn't work out how to add the whole file so cheated and copied a section from a pdf "how to" I have on this ...

"You also need two 1/8" NPT to 3/16 hose barbs, to match the hoses on the SE. Buy online or source locally, cost me $12 to have some odd sized ones turned down to fit but I live in BFNW... Shop around.

It's a good chance to check the hoses you've got; chances are they're getting hard or cracking. Replace as required.

Plumb the manifold house to port 2, the Boost Sensor to port 1, and the filter on port 3.

I used some RTV silicon to ensure the threads sealed without over tightening.

Remove the old solenoid valve and secure the new one under the frame with a big fat cable tie. Or get crafty and drill some mounting holes.

You'll need two 6.3mm spade terminals, male, to crimp onto the new wires. Secure them into the OEM plug with some small cable ties or heatshrink. Use a small screw driver or pick to close up the female spade connectors; they get loose with age. (Just like some old girls I know.) Polarity doesn't matter.

You're done."


Edit ... Lachy just beat me

Sent from my SM-G930F using Tapatalk

Yeah, but you had better details!