1999 ford explorer runs rough when cold

|When its cold (below 40 degress) my explorer will idle rough for a minuteor |so, then it idles normal. I checked my fuel pressure and it is at 59 psi |when it should be running between 35 to 45psi.When i pulled the vaccum line |off the fuel pulse dampner the fuel pressure stayed the same. It is throwing |a code saying that it is lean or rich conditions on bank 1 and bank 2. My |question would be is what could be causing this to happen? |I have changed the mass air sensor,the throttle positioning sensor,the idle |control sensor,the fuel pulse dampner,fuel filter,new plugs and plug |wiresand oxygen sensors.help!!!!

Reply to
Dale
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|When its cold (below 40 degress) my explorer will idle rough for a minuteor |so, then it idles normal. I checked my fuel pressure and it is at 59 psi |when it should be running between 35 to 45psi.When i pulled the vaccum line |off the fuel pulse dampner the fuel pressure stayed the same. It is throwing |a code saying that it is lean or rich conditions on bank 1 and bank 2. My |question would be is what could be causing this to happen? |I have changed the mass air sensor,the throttle positioning sensor,the idle |control sensor,the fuel pulse dampner,fuel filter,new plugs and plug |wiresand oxygen sensors.help!!!!

Reply to
Dale

When its cold (below 40 degress) my explorer will idle rough for a minuteor so, then it idles normal. I checked my fuel pressure and it is at 59 psi when it should be running between 35 to 45psi.When i pulled the vaccum line off the fuel pulse dampner the fuel pressure stayed the same. It is throwing a code saying that it is lean or rich conditions on bank 1 and bank 2. My question would be is what could be causing this to happen? I have changed the mass air sensor,the throttle positioning sensor,the idle control sensor,the fuel pulse dampner,fuel filter,new plugs and plug wiresand oxygen sensors.help!!!!

Reply to
Dale

======================== When you say "fuel pulse dampner" do mean the "fuel pressure regulator"? If you pull the vacuum hose off, at idle and it has *vacuum at the hose*, (you should check that), the pressure should go higher that when it is on. If you checked it correctly it sounds like the regulator is bad. When the regulator has vacuum and the pressure is to high, the reg is bad. What code is it, lean or rich? You say lean and rich, that makes no since.

Reply to
Scott M

Red flag, it's higher than called for.

Another red flag. Also a clue.

It is either a rich code or lean. did you get any of these codes p1130;p1132;p1138;p1150;p1152;p1158? If others what codes did you get?

You have already answered your own question.

Will do nothing for an over pressure problem.

If you are really getting 59 psi and you replaced the regulator, you need to take a close look at the fuel return line and pump assembly.

Reply to
Thomas Moats

you pull the vacuum hose off, at idle and it has *vacuum at the hose*, (you should check that), the pressure should go higher that when it is on. If you checked it correctly it sounds like the regulator is bad. When the regulator has vacuum and the pressure is to high, the reg is bad. What code is it, lean or rich? You say lean and rich, that makes no since.

Reply to
Scott M

Reply to
Doug S.

I have a 2000 Ford Explorer Sport that does nearly the same as this guy's '99. Except when I crank it, it will idle for about 10 seconds and then chug down to less than 1k RPM's before "chugging out" after a few seconds. I get Codes 171 174 stating Bank 1 and Bank 2 running too lean.

I'm no where NEAR a mechanic.What's the matter? Thanks! Grateful John

Reply to
Slappy

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