I have a 4dr civic lx with a z6 swap. Cylinder four will not fire. It seems to be getting fuel and and has a strong spark. Compression is good across all four cylinders. I have tried new plugs, new wires, different injectors, different dizzy, different ecu and nothing seems to work. Is there anything that i am missing that would cause this to happen?? I also thought that it could be a timing issue but wouldnt that effect all four cylinders?

 

this seems contradicting. how did you test to see if #4 isnt getting spark?

 

To check it i pulled the wire off of the plug and use a screw driver to ground it to the chasis. It was a strong spark.

 

hows cylinder #4's condition, compression wise?

 

compression test read 160-150-150-160

 

see if its getting fuel to #4

 

I can smell fuel on the plug itself. And i have tried switching out the injectors with a new set. Is there another way to see if it is getting the proper amount of fuel?

 

Double check if you have the wires on the right firing order. The way it sounds is that if you smell fuel, have spark, compression, and airs getting in the motor, then if the firing order is off it will spark when it isnt supposed to. Its weird to have all the requirements to run but no power. Make sure the dizzy is in good condition and the crank sensor since you switched to an obd1 engine

THink about it. it sparks but it also has fuel and wont run....

 

I have triple checked the fireing order and i know its right. If it were off i would expect have more than one cylinder being dead. If it were a dizzy issue wouldnt i also have a issue with more than one cylinder too?? I would understand if i wasnt getting a spark that it could be a bad connection in the dizzy but i have a strong spark.

I am leaning that the spark may not be occuring at the right time but i dont think that it could be timing with it only being one cylinder. What else could cause it?

 

I understood what you were saying and i know crossed wires would show up as more than one off but i;m looking at the whole picture.so from my understanding the car runs on 3 cylinders, although the 4th has everything it needs to make power but so do the other cylinders yet they have no issues correct? Strong enough spark, fuel is present, compression's good and presumably its on time if the others are firing at their times. And youve already tested everything from the injector, spark plug, wire, terminal, rotor. And t-belt and components are in good shape and on time. Hmm thats interesting but i know you'll figure it out

If i were to shoot into a dark room with a guess its a component of that cylinder. not something that affects all of them like a stretched t belt would through the timing of each cylinder.

 

Do you no of anything that could cause any of the major components (i.e fuel, spark, or compress) to occure at the incorrect time for just one cylinder? Like a senor or anything like that?

 

off the top of my head for spark if the end of the dizzy is flipped 180 degrees but it would throw timing way off, as would a worn t-belt or belt being off a tooth. If you suspect timing is off, pull off the upper timing cover and turn the motor while its at TDC for #1 and make sure the gear is pointed up, and the rotor on the dizzy should be pointing at the #1 cylinder terminal that would show that its on or off time. Then shoot timing with a timing light. Timing affects when the injector fires, the VSS controls how long theyre open when the cars in motion.

Compression wont be off time. Im thinking if there is a sensor that would affect one cylinder but i cant think of it right now. But if i can i will let you know. But since its isolated to that cylinder i wouldnt think a sensor would affect it unless it is a sensor that has a wheel that spins with the motor and that terminal or section of the wheel is worn or damaged (like taking off a terminal in a distributor cap). Even though you said the spark is strong and fuel is present, a weak spark (bad plug or ignition wire) or dirty injector could cause a lack of power too. Just throwing it out there. You'll figure this out man just take your time

 

Update:

Just to be sure it wasnt an injector problem i switch the injectors for cylinder 4 and 3. Still had the same problem with cylinder 4 being completely dead.

 

do you have a CEL on?

 

after goin back threw the fuel system I found that cylinder 4 has no signal to the injector so it is the lack of fuel causeing the dead cylinder. I checked the constant threw the engin harness and it was good. Now to dig deeper into the wiring mess and find the problem.

 

See it was isolated to that cylinder! Now that you diagnosed it, and knowing the injector has a 12v supply which you checked and the ecu grounds it to fire but its not getting that signal, follow the wiring back to the ecu just like the flow chart would tell you. You'll find it

 

Found a loose pin in the plug connection from the engin harness to the chassis harness. Thanks for all your help.

 

Perfecto! Glad you found it man. Now go enjoy your motor!