i have a 89 Si with a obd1 converted b20b , car ran fine for a few weeks . Now when I try and keep my foot steady on the throttle it hesitates and starts to miss..The car runs fine when I apply enough throttle , It doesnt bog or anything like that, As soon as i give it a decent amount of gas it clears up. It did throw a CEL but I turned the car off and It hasnt came back on since...Any ideas? the motor is fresh , only has 30,xxx miles. The dist. I bought used when I bought all the obd conversion stuff. The car has I/H/E . Does have a walbro 255 pump from when it was boosted but it ran fine for the first few weeks

 

does this happen cold or only when the engine is warm?

 

seems like its a little bit of both , I would have to say a lot worse when its cold

 

anyone?

 

ttt

 

chances are if you didn't disconnect the battery, the ecu saved the code. Check it. Other than that all i would think of is o2 sensor. Since this sensor mainly works at idle and half throttle.