Did I pop my Motor???.... Bad idle
 

I recently installed my SMIC(no duct - on order) and Hi-flow cat. Soon after my Idle got pretty bad. It idles rough sometimes and sometimes dies at stop lights. Sometimes it idles fine.

Someone please tell me that I didn't "fry" my apex seals. BTW, There's no white smoke when I start it up in the morning. Could the "More open" exhaust or having the airpump hose not being connected to the cat be the cause for a bad idle?

If I get a compression test, What should I look for?


~ John

good ole map sensor check is always the first thing to check

Re: Did I pop my Motor???.... Bad idle
 

You installed a high-flo cat and didn't connect the airpump?

When I was testing a problem with my airpump, I had it off and the car could barely idle. Connect that bad boy up before you begin to start your new High-Flo cat on to an early death. ;)

Johnny,

Excuse my ignorance...What the hell is a map sensor check???

John

Re: Re: Did I pop my Motor???.... Bad idle
 

Mahjik,

The guy at N-tech said that I didn't need to use the airpump with their hi-flow cat. Isn't that why it's capped off. However, I do plan to connect it. I just need to have someone weld the pipe from the airpum to the cat. I may just cut off the old flange from the stock cat so that its removable.


I hope that's the problem.

Thanks,

John

Yea, when you remove the airpump, the idle becomes crazy if you are using the stock ECU. So, you don't "need" the airpump, but without it, you probably won't pass an emissions test (if you have them in your state).

I will "almost" bet, that is your problem. I don't think there is anything wrong with your car at all.

Re: Re: Re: Did I pop my Motor???.... Bad idle
 

No need to weld the pipe. This weekend I put a high flow on. I just got some silicone heater hose from NAPA, a couple hose clamps and cut the pipe off the OEM cat. Use the silicone hose to connect the two. This way you can easily put the OEM cat back on if needed.

I had the same arrangement on my 2nd gen hi-flow for years with no problem.

You may have to ask for the hose at NAPA, they had it behind the counter for customers installing hi-flows.

Re: Re: Re: Re: Did I pop my Motor???.... Bad idle
 

Thanks Grampa! I was freaking out. I'll try the silicone hose job tonight.

~ John

Ok, here's an update. I couldn't find anyone who carried the silicone hose that Grampa mentioned. Napa, Kragen, and some muffler shops had nada. So I ended up paying $35 bucks to have a tube welded to the oem tube. I had them cut the stock flange off and decided to save it just incase I need to reinstall my oem cat.

The car seems to idle smoother around 700 rpms, but when I "blip" the throttle a bit an let the idle settle down again, the car dies! It bounces a bit and then just dies. Hmmm.

I am going to ge the fuel filter changed today too (@ C2 Automotive, Oakland) and ask them to check out the idle issue for me.

John

I have the same problem, what else could cause rough idles?

bad plugs/wires

Plugs & wires huh? I just changed the plugs 2000-3000 miles ago...

YOU NEEED DUCT for IC! AIR DUCT IS IMPORTANT!!!
W/o air duct.. u won't get much air to ur IC.

I hear you! I have ordered one from Pettit for my M2 MED SMIC. I bought a used one w/o the duct. Pettit is just taking their sweet time to send it to me. M2 wont sell duct separately. Do you know any other places where I can buy a duct??? I can just cancel my pettit order since they haven't sent it yet.

Pettit is only place i know
try to use ur stock duct
or make ur own.. have a trip to homedpot... and find something to make ur duct.. :) it wil be better than nothing

I had similar symptoms and I hate to say it but mine was a bad coil. The coil pack is in the worst location possible. The coils are right below the throttle body on top of the motor. Mine were fried and a like black oil was leaking out. What Mazdu was thinking I don't know. I think I'm moving the coils someplace cooler.

Later, Jeff

Check the boost sensor mounted to the left drivers side of the throttle body mounted on the firewall
Check that your plugs are not fouled and that your wires are ~0 ohm resistance
Check your idle control screw located under the throttle body elbow near the firewall (actually on the throttle body)
Check your throttle body springs for proper return
Check your Throttle Position Sensor (PFC makes this very easy, but on OEM ECU, refer to the manual)
Try putting a 250 resistor (someone correct me if I'm wrong) on the air pump connector.
Do not run your car under boost under any circumstances, the intercooler duct is a performance measure and on an OEM ECU, an upgraded IC is normally a no-no, but get this idle thing fixed before you worry about 5 more hp out of that IC, it's possible you have 50hp... If none of this fixes that blip/idle problem, get a compression check. Good luck.

Richard

Thanks for the great suggestions Richard. I just took my car to a good rotory shop(C2 Automotive in Oakland - 510-272-9869).

They checked the compression on my car and it turns out that my Apex seals are intact! I was so relieved to hear that. The compression was even on both rotors. The problem causing the idle is that my airpump is not turning on. I must have screwed something up while installing the IC... Will(mechanic) didn't have time to diagnose the issue. He said it could be the throttle position sensor is not working, telling the ecu to "turn on" the air pump at idle.

I would like to try and troub le shoot this before resorting to bringing my car back to the shop($$$). Anyone ideas on how to check this stuff?

~ John

even with the air pumpe off it should not be too bad but you can raise the idle 150 rpm's or so and that should help it recover or idle better but if in fact that the airpump is not working then you will have a little bit of a lumpy idle:)

BTW the airpump always runs at idle it shuts off above 3600 rpms or close to that:D

oh yeah with all that said just ditch the air pump it is only for emmissions! get rid of it IMO

...Rikki,

That's funny. I was actually posting a "WTB: Midpipe", and I can just disconnect the damm airpump and remove the hi-flow cat. I don't want to kill my new cat.

Do flames "always" shoot out with a midpipe? Or is it under certain driving condsitions? I was driving to work today and I had a cop on my ass for a few blocks...

John

I would say MAP sensor, or the air pump too. I just fixed mine from running like shit today too.

As for the flames. Usually they only come out when you get on it. And the downpipe does help a ton.

...Zero,

How do fix the MAP Sensor? I don't even know what that is... Also, what did you do to the air pump? I checked all the connections. The mechanic said that the signal/current coming from the ecu wasn't getting to the airpump.

John

Hey, if you get that midpipe I will buy your Hi-Flow cat off you. Let me know.

OK, It only has 900 miles on it.