This problem is a little difficult to explain so please bear with me. I have an 88 Formula with the stock 6cyl. Here's the problem... While I'm driving and I depress the gas pedal and slow down (without pushing the brakes), just as the engine decelerates and hovers between idle and deceleration, it feels like the engine is sputtering – but it’s very subtle. It’s very similar to “very” gently tapping the brake pedal at a high rate of speed. Does that make sense?
The engine doesn’t jerk around, there’s nothing violent, no back firing, etc… I can’t figure out what could be causing this. Also, it is idling at 1500. Could it be a faulty ECM?
Thanks for any input & ideas
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10:01 AM
PFF
System Bot
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
Just a guess here but if I understand you correctly, you are driving along and you let off the gas and you get a slight surge? Maybe your IAC is jumping around (hunting) for idle? Maybe a vacuum leak - also the cause of your high idle. That's where I would look first - for a vacuum leak.
Try banging on your CAT and muffler with your fist to see if you hear anything rattling around. Could be an restricted exaust. Also, check your EGR tube for leaks/cracks as this is a known failure mode that causes high idle.
