1998 Ranger, 2wd, 2.5L

My Ranger has just started dying when it starts in the morning and when warm it 'lopes' or idles roughly. It has app., 115,000 miles. It has run great until recently.

I put in a new fuel filter, no change. Some one suggested an oxygen sensor. I'm not sure how to disconnect to test it, but I doubt it is this sensor because it doesn't begin affecting performance until the it reaches 600 degrees.

My next guess is the fuel pump.

Any suggestions?

Thanks in advance...

Reply to
Tom Jefferson
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If you can get a pressure guage, you can measure the fuel pressure in the lines. It ought to be around 40 psi, I believe. If you have low pressure, then it could be the pump. If you have pressure then the pump isn't the problem.

Perhaps the IAC valve. I've been told that's the problem with my BroncoII. I'm still working on mine and trying not to spend money on parts and tools I don't really need now :-).

-D

Reply to
Derrick 'dman' Hudson

Do any of the warning lights come on?

Reply to
Luke

Had a mechanic in here just the other day talking about the same problems with a Ranger he was working on. The problem was the Mass Air Flow Sensor. Don't know it that is your problem but it may be worth checking out.

Reply to
jt

Take a 2 lb hammer and tap on the air bleed throtle body. It is a cure that works for the rough idle on mazda and ranger 2.5 L trucks. tap it not slam it.

Reply to
Lesedan

A "Rule of Thumb" is that you should tap no instrument any harder than you'd tap the bridge of your own nose...

HR.

Reply to
Rowbotth

If you're talking about the "idle air bypass valve", mounted on the intake near the throttle body, it's best to take it off and clean it. It is bright metal colored, shaped like a D-Cell battery, with a small electric motor and plug on one end.

With the engine turned off, unplug the harness connector from it, remove the two bolts which connect it to the intake manifold, and clean the housing of the valve thoroughly with carb/throttle body cleaner. Saturate the inside of it, note there are two sides of the valve and clean both of them. Be careful not to damage the gasket, or you'll need to purchase a new one. Be sure it is dry before you re-install and start the engine. You may note a slightly rough idle until the valve resets itself, usually after driving the vehicle in excess of 45 mph for a short distance.

This is the correct procedure, and should be repeated/serviced about every

30,000 miles.

Good luck!

Spdloader

Reply to
Spdloader

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