Help! Loss of Power, Low Idle, and Stalling!

[IllaNoizeTV]

Hey guys so I've had my MSP for about a year and a half and last month all of a sudden My MSP would have really low idle (400-600rpm) and loss of power until I get to about 4k rpm, then the power would come back. When at idle it would want to stall sometimes. Ever since I replaced the water return elbow the problems started. These problems would happen until the engine is completely warm. Once engine is completely warm then it would run fine.

These are the parts I've replaced trying to find this problem:
New EGR Valve
Cleaned MAF Sensor
New IAC valve
Year old spark plugs and boots
Checked coil packs and they are good
New VTCS and checked VICS and it's good
Smoke Tested and boost leak tested and there are no leaks
New Engine Temperature Coolant Sensor
Burped Coolant system

But my problem persists. Does my ECU need a flash? What else could it be? Any help would be much appreciated.

 

[hornsfan10609]

You have a mechanical problem, the ECU reflash won't do anything to help. You either have a vacuum leak, part of the ignition system is failing, your VICS flaps are stuck open, your EGR is stuck open, dirty MAF, even a loose battery terminal could cause some of this to happen. There are a lot of possibilities, just keep it simple and check one thing at a time. And don't assume that a new part from the auto parts store is a 'good' part.

 

[IllaNoizeTV]

I pretty much have the same problem as the person in this thread:
http://www.mazdas247.com/forum/show...rough-idle-loss-of-power-not-sure-please-help

But no one ever found out the answer. How do I check if the VICS flaps are stuck open, and how do I check to see if the EGR is stuck open? The terminals are fine. I just disconnected it and reconnected them yesterday. The only engine codes are: p0507 and p0090. Sorry I'm not too mechanically inclined.

 

[hornsfan10609]

Has the idle screw ever been tampered with? You could try a new/used TB. If the EGR is new it probably isn't sticking open but it's possible. The VICS and VTCS flaps have rods that connect to the actuators on the passenger side of the intake manifold. You can move them by turning the rod. P0090 is likely the solenoid on top of the intake manifold near the TB with the brown connector. It also sounds like a boost leak in the charge piping or a dirty/failing maf sensor.

http://www.mazdas247.com/forum/show...han-Expected&p=6355353&viewfull=1#post6355353

 

[IllaNoizeTV]

Yes the idle screw was tampered to increased rpm idle but the problem started before its ever been tampered with. The VICS and VTCS actuators were tested by my friend and I and they worked fine. The solenoid on top of the intake mani is the IAC valve right? That was replaced by a 30,000 mile one a few weeks ago. There is no boost leak, I replaced MAF and it had no effect. Do you think its the fuel pump?

 

[hornsfan10609]

The IAC is on the throttle body, the FPR solenoid is on the Intake manifold with the brown plug. I would try a new throttle body with a new gasket if it hasn't been replaced before. If the idle screw isn't in the factory location it will throw off the ECU.

 

[IllaNoizeTV]

I just don't want to keep spending money and throwing parts at it, like you said. I'm gonna check with a local mechanic who knows our cars in and out within the next month. I'm really trying to keep the msp but with the water leaking every time it rains and these issues, its really discouraging.

 

[IllaNoizeTV]

I think the loss of power and low idle is caused by my cracked exhaust manifold which can also be affecting the reading on the o2 sensor.

 

[hornsfan10609]

If it is missing hardware and leaking that may be possible but if it's just cracked it won't make much of a difference. I had a cracked mani for years and it always ran fine.

 

[IllaNoizeTV]

It's missing a bolt.