2.3 idle and low rpm problems

[ncsdaonex]

i have a 1990 ford ranger 2.3L 4 cylinder, i had the computer checked and it had no codes, i cleaned my mass air flow sensor and that helped slightly but then the problem returned as bad as before. When it is cold it runs decent but when it is really cold it does it and the one day it was warm instead of cold and it ran horrible. What it does it when i start it up it fires right up every time. If you wait 5 to 10 seconds the idle will drop drasticlly then return to normal. It will do this over and over again. It will stop for a while and then start again. It also does it when im driving and it feels like your taping and letting off the gas real quick. Now when i run the rpms up high and get the motor warmed up real good it wont do this. I dont notice any loss in power when it does this. Also, sometimes when the idle drops real low it will shut off and when it does i have to crank the motor over and pump the gas for 25 to 30 seconds before it will start back up. When it does finally start i hit the gas and until the rpm's get up it sounds like it is missing or something, but once the rpm's get up it runs fine but it might start doing the idle thing again. Please someone diagnose the problem!!!

 

[tomw]

Check for codes stored in the computer, as it may tell you that something is out of specifications, such as the coolant temp sensor, or the incoming air temp sensor. Either of them could make the engine run bad when the air or engine is cold. Remove the vacuum line from your fuel pressure regulator and check for gasoline. If you find gas inside the regulator where the vacuum line attached, you have a broken pressure regulator diaphragm and need to replace your regulator.
How old are the spark plugs and wires? If old, you may be getting crossfire, where the spark jumps from one plug wire to another before getting to the spark plug. That will cause misfire and a shaky idle.
Have you cleaned the IAC , idle air control, that regulates your idle speed? If it is gummed up, it cannot open and close properly to adjust your idle speed.
Go through this and let us know...
tom

 

[ncsdaonex]

Check for codes stored in the computer, as it may tell you that something is out of specifications, such as the coolant temp sensor, or the incoming air temp sensor. Either of them could make the engine run bad when the air or engine is cold. Remove the vacuum line from your fuel pressure regulator and check for gasoline. If you find gas inside the regulator where the vacuum line attached, you have a broken pressure regulator diaphragm and need to replace your regulator.
How old are the spark plugs and wires? If old, you may be getting crossfire, where the spark jumps from one plug wire to another before getting to the spark plug. That will cause misfire and a shaky idle.
Have you cleaned the IAC , idle air control, that regulates your idle speed? If it is gummed up, it cannot open and close properly to adjust your idle speed.
Go through this and let us know...
tom

okay i will check those things but where is the fuel pressure regulator located at and what does it look like.