I have a 91 civic base, dual point injection that runs well at idle and with light throttle. But at maybe 1/4 to 1/3 throttle application it begins to crap out. It is OBD1 and is not throwing any codes. The top fuel injector is spraying fuel and if I disconnect the lower injector at idle the engine dies. Fuel pressure is good. Plugs are good, and I've even checked compression; 155 - 160 all cylinders.

The car was running fine and just started this a vew days ago. Any ideas?

 

i would check the resistance of the bottom injector and make sure it still has proper current for the wiring. give that a shot. youll need a dmm.

 

OBD1 and still DPFI? Interesting.

Line the engine up and check everything is still at TDC?