problem with #3 cylinder please help

[hotrod240sx]

first off it was running just fine shut it down drove my truck the next day to work, the went to drive the 240 a couple days later wouldn't start, finally got to start, not doing anything on #3. has to cap, rotor, plugs and wires. i know i am getting fire to the plugs and i do have gas on the #3 plug. also done changed the whole injector rail just incase it was a prob with the injector. when it cranks it runs rough and has the miss. please help i love to drive the car and it handles better and gets better mileage than my 84 chevy truck with 502 H.O. crate motor making over 500 horse. if this 240 keeps agrivating me i'm going to v8 it with old school chevy, but hate to. 91 model with hicas

[kennymillsjr]

well maybe your harness were it connects to the #3 injector has a lose connection crank it up and wiggle it and see if it changes at all..and let me know what happens

[liquid_cool]

well maybe your harness were it connects to the #3 injector has a lose connection crank it up and wiggle it and see if it changes at all..and let me know what happens

if its not what kenny says..then i would pull the #3 spark plug out and rest it against the frame..then have a buddy cranck the car over..check for spark...if you dont have spark..test your cam position sensor in the dizzy..if you do...replace the spark plug...get a test probe...unplug the #3 injector ...look inside the plug its self...you will need to ground to one side while holding the probe against the other side..if you cant get your probe( the type that has the lightbulb in it) to make contact with the pins...stripp (2) small pieces of solid wire and use those for contact points...now..have a buddy start or crank the car over..if the probe lights up..your recieving signal to the injector..if not..you need to follow that set of wire's down the harness and look for dmg...if you find no dmg at all..and you can conferm this by checking the congruity of the wire with an OHM meter at the pin by the ecu to the pin of the injector...if its not the wire..then its the injector block in your ECU its self...they have been known to have a random block fail from time to time...hope this puts ya in the ball park..good luck

[kyoung]

Buy a Noid light and unplug injector harness and plug into Noid light. It should blink while running if operating correctly, if solid light you could be having an Ecu problem.

[hotrod240sx]

finally got it staright with my luck lately i went the ecu route being as i had done changed the entire injector rail. sure enough that fixed it, only to find out the front timing cover seal started leaking, fixed that also. thanks for the help. and it is a good thing i had done elimintaed half the stuff off the front of the engine a while back, made it a lot less agrivating to change the seal thanks again