I have a 1992 Ford Escort XLE with a 1.8L engine that does not want to idle. Also it bucks when you take off in gears 1-3. It smooths out when you get up to speed. I recently had to have the timing belt replaced.The car had been running rough and then the timing belt broke. After replacing the belt there was some engine surge while in first gear but has gotten progressively worse. I have replaced the spark plugs and air filter with no signs of improvement. Any help diagnosing would be appreciated. I'm out of ideas short of trying to drive it to a mechanic and hooking it up to a diagnostic scanner.
Possibly a dirty throttle body or a dirty IAC valve. There is throttle body cleaners that do a good job of cleaning the carbon out of the throttle body. You can use it on the IAC valve also.
Thank you for your response Way2old.When I went to check the throttle body I found a split in the inlet air duct. I wrapped it with duct tape for a test and car ran great so I'll get a new duct and hopefully solve my problem. You definitely were in the right neighborhood. Thanks so much for your help.
Having a cracked air duct can mess up the signal from the mass air sensor. The idle air control, oxygen sensors map sensor and throttle position sensors all are trying to compensate for the air leak at the air duct. This gives the poor running condition.
Way to old is also right. The idle air control motor and throttle valve could be clogged up with carbon causing the engine surge and stalling. Cleaning them with the cleaner mentioned works well. This is also a maintenance item which should be done at every tune up.
Replacing the air duct and cleaning the throttle valve and idle air control motor will get you on your way.
Glad you're still around helping with user's questions.
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Hope all is well,