Misfire problem s13 ka24de!!

[fuco8210]

Ok i swapped in a 93 ka24de into my 92, everything is fine but as of late it tends to misfire badly at idle and under low rpm at partial throttle. It runs fine and clear for the first minute on a cold start, then once warmed fully it starts to get really bad. I swapped distributers with a known working one; that didn't do it. So next i did plugs which were cheapo denso autozone plugs, gapped to .38; that didn't do it either. Next I did plug wires with the same outcome. Codes thrown are, 13, cts which i replaced and its still throwing the code; 14 vss? and 33 front o2.. None of these should be the cause of my problems though? Could it possibly be a bad/clogged cat? Or maybe the ignition coil? Any insight is appreciated.. Thanks!

[fuco8210]

anyone?

[nissans13240sx]

bump for this thread im in the same boat.

[sohcistehsex]

Ok, I will try to help u guys but its basically a process of elimination through testing

first are you sure its a misfire because sometimes a bearing knock can sound like a misfire if its not too bad yet

if its not a knock and you are sure its a misfire then

get a spark tester(little glass tube goes in between a wire and plug) and find out if you are getting a good spark but you need to make the engine misfire like it does normally if its at partial throttle

if you have good spark then you know its not spark so get a fuel pressure gauge(get one with a t-gauge because it doesnt have a valve on the fuel rail) and hook it up between the hose coming off the fuel filter and the hard line

you should have 34psi at idle i believe see if its got low fuel pressure under partial acceleration(its very possible that its a fuel filter or fuel pump issue) now take the little hose off the fuel pressure regulator(little thing attached to the fuel rail with 2 screws on the back side of the motor)fuel pressure should go up to 42-44psi at idle

if you have spark and fuel then you have to check compression with a compression tester

if all 3 are good then check the mafs

thats basically what you gotta do to find out why its misfiringif you test it post the readings and ill try to help

[nissans13240sx]

i am positive the 3rd cylinder is misfiring on my kade. pull the plug wire and no idle drop. I changed the wire with a know good one, same with plug. I check compression 180psi all four cylinders. I checked spark definatly good. I replaced the o2 sensor. also i spun the distributor while it was out to listen for the injectors clicking and i belive they all are. The only thing i havent done yet is the fuel pressure test. I also swapped the mafs with a known good one and there is no difference.

[nissans13240sx]

bumping this thread again cause i dont wanna start a new one.