I am having a idle problem in car, there are two pipes on solenoid valve, w vaccum pipe the car idles low and high and when I put it back the car switches off. I have a 2006 ford fiesta 1.4i duratec

Could be vacume pipe air leak check all pipes especially the one that goes to throttle body or possibly idle control valve

Idle speed control valve stuck(clean with carb cleaner), possible split in vacuum pipe or one has come off. Check all vac pipes, spray around vac pipes with the carb cleaner with the engine running, see if engine speed changes, if it does you have a vac leak.

Hello my name is autoteck21 sounds like you dealing with one of two things. #1 Either you have a vacuum leak in one of your hoses or your vacuum box at the worst case one of your vacuum control solenoid. #2 Your idle air control module (under your throttle body.)
To test #1 take a can of brake clean or carb/choke cleaner and in small 2-3in areas spray little spots while engine is running listen too your idle for any changes (you will here the differences) if so there's your leak.
To test #2 find the little connector (2 wire) under your throttle body (when standing in front of your car lower front side under intake pipe hose clamp)

The purge solenoid valvend canister are part of the EVAP system. The automatic diagnostic method tests the integrity of the EVAP system for leaks by pressurizing everything and then checking to see if pressure is lost. The filler cap is the main seal to the gas tank and if this is loose then compromises the ability of the system to be pressurized. Put a film of grease around the rubber seal and fit the cap tightly.

The following is a brief overview of the system (any spelling anomalies are due to my British background). I hope you find it helpful :-

What is it? The EVAP system is a collection of pipes and devices designed to prevent fuel vapour emission to protect the environment.

Where is it located? Pipes run from the top of the fuel tank to the carbon (vapour trap) canister which can be located between the inner and outer fenders (wings), on the inner fender or on the firewall (bulkhead). A pipe connects the canister to the throttle: the pipe exits just in front of the throttle plate.

How does it work? The EVAP system passively stores the vapour from the fuel tank in a charcoal filled canister. When the engine is running above idle speed the ECU opens a purge valve to the pipe leading to the throttle body. A vent valve allows the ingress of air into the canister and this encourages fuel vapour to be drawn out through the purge valve to be added to the air intake mixture to be burnt. The opening of the purge valve cycles with engine speed. The purge valve should be closed during idle.

Symptoms of faulty EVAP

• Erratic idling - If the purge valve fails to close the ingress of unmetered air will compromise the ECU's ability to maintain a suitable air/fuel ratio.

How to check? Simply clamping off the pipe from the EVAP purge valve should result in an immediate improvement in engine idling performance. Remove the purge valve and try to blow through it. If there is resistance then the valve is mechanically OK. Applying voltage to the electrical connections should open the valve and remove any resistance to blowing.

How to fix? If the valve is jammed open permanently or fails to open when signaled to do so then replace it. It may be possible, taking the greatest of care in the process, to open the valve to clean it up in the hopes of affecting a repair. If the solenoid itself, however, shows 'open-circuit' due to an electrical break it is best to replace it.

My 93 s10 blazer idles really ruff and i
erratically for the first few minutes until it warms up. It now sound like its going to stall every morning I start it up and black soot comes out the tail pipe onto the pavement but only while its idling rough. After i changed the cap and rotor it idled good for a couple days then started doing it again.Already changed the fuel filter and pcv valve. whats the problem?

try flushing the heater core out with a garden hose ,as for the idle well this vehicle is different to the europeon models for this age so i would advise asking a local mechanic to have a look for you but i suspect the idle control valve ,but in all honesty any electrical components can be affected by the cold from radios to sensors or stepper motors like what control the idle

you cannot ,its idle control valve and its either faulty or the ECU needs reprogramming ,so i would return it to a dealer who has the correct software

before you spen money on a idle control valve look at the engine breather pipes,and look good for a split or perished pipe

If you mean idle speed control valve ISCV which allows the right amount of air pass the throttle flap when the engine is idleing so it dose not stall then the only thing you can do is clean the inside of it the best you can and remove the oily **** that builds up inside and stops the solidnold moving. If this fails a new one is the only option.
If you also mean a vaccume swithch which opens and closes to allow vaccume to operate different components and has at least 2 rubber pipes attached there is no fix as they are seal units. Just check the pipes are not spilt or fallen off. hope this helps

P1557- Charge Pressure Control: Positive Deviation Possible Symptoms You May have overboosted I would chek out the EGR make sure it is open.

• Reduced power output
• Limp mode

Possible Causes

• Boost Pressure too High
• Hoses/Pipes incorrect connected, disconnected, blocked or leaking
• Charger Pressure Control defective
  • VNT (variable nozzle turbo): nozzles stuck
• Solenoid Valve for Boost Pressure Control (N75) defective

Possible Solutions

• Check Hoses/Pipes to/between Components
• Check Solenoid Valve for Boost Pressure Control (N75)
• Check / Clean / Replace Charge Pressure Control
• Check / Clean mechanism for variable nozzles