what the problem is?

Holy s*** Batman! Guys, go tighten your clamps. I have my old MSP back...well almost. I went out and tightened every worm gear clamp on that hardpipes and intake piping with a 10 mm socket wrench. Some of them were fairly loose, but there wasn't any obvious gapping anywhere. You wouldn't believe the amount of difference that it made. It eliminated about 95% of the surging and bucking. Damn! To think that it was that easy. I still get some of the surging now, but it is fairly rare and not as bad as it was before.

The car is going in on Tues to have the front axle that broke under surging replaced. I am going to have the tech look at the piping to make sure that there are not any cracks. If there are cracks, I will ask the dealership to pay for hardpipes because the stock charge pipes are on backorder and it takes 3 months to get them.

I also want to look into getting a different MAF for our car that is better able to record and tuned to the airflow entering the CAI.

R
 
i have tightened mine several times on my intake and ic pipes, changed all of my vacuum hoses w/ fuel line hoses, and i still have the same problem.

i have noticed however w/ the colder weather recently, the buckeling has stopped and the hessitation is nearly gone. not to rain on your party rainman (no pun intended) but has it gotten cold up there recently? someone please correct me if i'm wrong, but wouldn't the cold air play a role in leaning out the msp's overly rich mixture?
 
It has gotten colder recently, but problem was worse on cold evenings over the fall months previous to the tightening of the clamps. As I said, the tightening eliminated about 95% of the problem, but there is still some bucking at times. However, it is much less predictable or reproducible now.

I still have some of the hesitation despite the ECU flash. I reset my ECU again today and it hasn't seemed to make much difference yet.

R
 
Update 2: Went to speak with a local tuner today about my plans for the car. When we talked about the bucking, he wasn't sure what the problem was, but wanted to check under the hood. I explained how I had tightened all the clamps which had served to minimize the problem. While checking all the connections, we wiggled the BPV recirculating hose that runs between the stock intercooler piping and the stock intake/CAI depending on your setup. This hose is connected to a plastic nipple which was expoxied on in the original stock setup. This nipple was loose.

When I installed the CAI, this nipple had come loose at that time. After finding out from Mazda that the intercooler piping took 3 months to arrive since it was backordered, I spoke to the MSP tech who suggested to epoxy it back on. I did this and supplemented the whole thing with two worm gear clamps on either side of the nipple. Everything seemed fine although this is the same time that the CAI went on. This is the time that I really started to develop the bucking. The bucking got progressively worse until two weeks ago when I tightened all of the remaining clamps on the intercooler pipes and the CAI. AT this time I also removed the two clamps from the intercooler recirculation nipple. Most of the bucking was gone. It behaved like this for about two days. Then the bucking started to occur more frequently again and was getting progressively worse. Until today, when we saw the recirculation nipple. We slapped back on the worm gear clamps and tightened everything down and took it for a spin. Now, finally the old MSP is back.

That car pulled strongly from idle to redline without any bucking no matter whether I put the pedal to the floor, or whether I only went part throttle. I guess I'll have to JB Weld the nipple back on until I can get some hardpipes.

BTW, I noticed that my gas mileage had dropped off at the same time I removed the clamps and tightened the other clamps. The rear end of the car was beginning to look like the inside of a fireplace as well. All this since the fuel mixture was richened up to deal with the increased metered air, which would subsequently sneak out of the system through the loose clamps and the leak at the recirculation nipple. I'll keep an eye on the mileage now so that I can see whether it improves.

Bottom Line? Check all your clamps as well as the joint where the recirculation nipple leaves the top intercooler pipe on it way to the BPV. If it is cracked or broken, JB Weld it and slap on some worm gear clamps. Otherwise, get some hardpipes cause you'll be waiting a long time for the stock pipes to arrive.

R
 
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