1991 Civic Si with a DOHC OBD0 ZC. I'm running a Greddy kit with FMU and checkvalves.

The car hesitates really badly out of the hole... as in it almost stalls out and back fires/pops/crackles/lurches. Once the car is moving, it misses and lurches around at highway speed and gets worse if you push the gas down to accelerate. It isn't an occasional miss, rather an almost constant, but totally inconsistant one.

I have replaced the following...

MAP
TPS
O2 sensor
ThrottleBody
Plugs
Wires
Distributor
Crank Sensor
Check valves

The problem has not changed at all. Any thoughts?!?!

I'm really worried. The car has run fine up until the last few weeks when this problem came about. It has gotten worse and worse.

The fuel pump is about 2-3 years old and is a walbro. The fuel filter is only a few years old.

I'm going outside now to replace all of the injectors, the fuel pressure regulator, Air/Idle control valve, and the temp sensor.

The problem isn't too bad until the car gets to operating temperature, then it is horrible. It also gets better if I drive the car for 25 minutes or so, but it is still there even after a long drive.

 

Check cam timing??