'90 302 High rpms/surging

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Dec 14, 2010 | 08:05 PM

carrfamilynj

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From: Near Atlantic City, NJ

'90 302 High rpms/surging

One of my employees has a '90 E150 Club Wagon with the 5.0. It constantly idles at around 3000 rpm in park/neutral and only drops when he puts it in gear. I'm trying to steer him in the right direction with a fix but I'm not sure where to start.

Dec 15, 2010 | 05:02 AM

Greyf100

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check for vacuum leaks and clean the IAC. DO a base idle reset (have to google it for your vehicle)

Dec 15, 2010 | 05:05 AM

BlueOvalRage

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From: Oxford, Indiana

The first thing that I would try is pulling the plug on the idle air control valve while it's running. If the valve is working correctly, it will die and you'll know that the computer is driving the idle that high for some reason. If it continues to idle at 3000 (and I bet it will), then either there is a massive vacuum leak somewhere downstream of the throttle body or the idle air control valve is stuck open. The latter is the more likely scenario. Some of them can be disasembled and cleaned with carb cleaner or lacquer thinner and some cannot and must be replaced.

EDIT - It looks like grayf100 and I were thinking the same thing at the same time.

Dec 19, 2010 | 06:53 AM

carrfamilynj

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From: Near Atlantic City, NJ

Update to problem.

So a couple days ago the van just died. The high idle problem turned into a no idle problem. It will start fine and run for about 3 seconds then stall. If you keep your foot on the gas it will stay running, can lift almost all the way off the pedal and it will idle but then die immediately once you lift your foot off the pedal. We replaced the IAC valve, cleaned the TB and replaced the plugs, cap and rotor since it needed it anyway. Runs smoother now but will still not hold an idle. Also there is a very strong raw fuel smell when it's running, and he's had horrible fuel mileage for a couple months now.

Dec 20, 2010 | 04:59 PM

carrfamilynj

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bumpety-bump

Dec 20, 2010 | 05:12 PM

Kemicalburns

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From: Bend,OR

what did the plugs look like when you pulled them? if you pull the vacum line running to the FPR does gas come out?

Dec 20, 2010 | 05:48 PM

carrfamilynj

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From: Near Atlantic City, NJ

Plugs looked fine, just worn. Pardon my ignorance but I am not familiar with the FPR. I will look it up in the service manual. Thanks for your response.