i have a 1991 Honda civic dx hatch with the 1.5 dpfi. my issue is that when i start to drive the car runs rough once i put it in gear, seems like it has a back fire, and lacks a lot of power. but it doesn't do this 100% of the time but seems to be getting worse the more i drive. as well i noticed that my gas mileage is horrible i have gone almost a half of a tank and only 55 miles.

i have replaced the following so far:
plugs
plug wires
cap
rotor button
valve cover gasket (was leaking)
fuel filter
air filter

now when i pull the plug wires out of the car when its running the number one doesn't do anything the number 2 the car cuts off the number 3 car runs rough and the same for number 4 car runs rough. also when i loosen my distributor cap to adjust it to see if was off a lil there is no difference in the cars idol or anything.

if anyone could help i would appreciate it

 

Did you mean adjust the distributor? Because I don't think you can adjust the cap... Anyways, if pulling the #1 wire doesn't change anything then that cylinder isn't doing anything at all. Seems like #2 is the only one really keeping the engine alive. If you can, get a hold of a compression testor if you don't have one already and test each cylinder for compression.

 

ok will do

 

ok well i did a compression check number 1 barley hit 30 psi and 2 3 4 hit over 210 they were all pretty consistent with numbers btwn 210 and 215psi

 

i have 1990 dx d15b2 i had the same problem, i end up needing a headgasket

 

how would i know if its the headgasket and not the rings tghat car has never overheated

 

they sell a test kit that i've used before to determine if the headgasket is bad...

 

YOU CAN DO A LEAK DOWN TEST OR PRESSURE TEST FROM THE RADIATOR.

 

Yep. A leakdown test would give you an idea of where the leak is occurring.