Popping on decel Options

[markb]

As the title says, my stock 72 1.7 is popping a lot on deceleration. I thought it was an exhaust leak, but everything is tight. I thought it could be the stocker muffler wearing out, so I swapped it out for a fairly new Bursch that came on the new to me 71. Still pops, but now it's a louder, meaner sounding pop instead of the wimpy pops from the stock muffler. Any ideas on what's causing it? Injection misadjusted? Timing? Help me, please, it's driving me nuts! Not that it was much of a drive.... (IMG:style_emoticons/default/wacko.gif)

[Martin Baker]

My 74 2.0 had this problem on decel as well, with the "trailer hitching" effect. The engine was not stock, but this might apply (D-Jet car only). If I leaned the mixture out a little on the ECU, it decreased, then leaned it out until it was gone. It ran so smooth, and great throttle response. I also lowered the fuel pressure (within published limits of 28-32 psi) which helped some as well. I had been running it around 35 psi on recommendation from a couple people. I believe it was being caused by an over rich fuel condition that was passing by the exhaust valve and burning/igniting in the exhaust, causing the pop and a little buck. Counter clock wise on the ECU knob=more lean. If you decide to try this take note of the knobs current position for reference, before you move it. 72 may not have the knob. Never owned that early of a car....yet.

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