missfire code 71 & 72

[Vin D]

I just swapped a JDM D15B to replace a D16y8 that I blew in a 1999 honda civic ex and Im running into missfire codes 71 and 72. the car will idle but I am getting alot of exhaust backfire......Is this a timming issue or more a fuel or spark issue that has to do more with the distributor????

[Greenblurr93]

hmmm... sounds like u need to check your timing first.... then u can narrow it down from there.

[superbluecivicsi]

could be all three. misfires occur from alot of things. reset the cel. if it comes back on, then, first steps are.

check timimng.

check for spark.

then check for fuel.

[97integrals]

Originally Posted by superbluecivicsi

check timimng.

check for spark.

then check for fuel.

[sohcfreak97]

why would u check for spark and fuel? if ur car is running and mis-firing...in order to have a car run and miss fire...u will need spark and some fuel, i would check your timing and see if u have ur spark plug wires in correctly...and check if that ecu will work for that engine...

[97integrals]

Originally Posted by sohcfreak97

why would u check for spark and fuel? if ur car is running and mis-firing...in order to have a car run and miss fire...u will need spark and some fuel, i would check your timing and see if u have ur spark plug wires in correctly...and check if that ecu will work for that engine...

The number one reason a car mis-fires is because of faulty ignition components (i.e. rotor, cap, coil, igniter, plug wires, or spark plugs) or faulty fuel components (injectors, fuel filter, fuel pump, fpr). There are simple test that can be done to rule out any or all of these components. The fact that the car is running means nothing. If your coil is bad, not completely blown, the car will run but mis-fire. If the injectors on the cylinders that are mis-firing do not have the proper resistance the engine will mis-fire. I could continue, but I think you get the idea.
K-thanks.

[superbluecivicsi]

why would u check for spark and fuel? if ur car is running and mis-firing...in order to have a car run and miss fire...u will need spark and some fuel, i would check your timing and see if u have ur spark plug wires in correctly...and check if that ecu will work for that engine...

if you noticed the original thread said it was misfiring in cylinder 1 and 2 (CEL71 and 72). these misfires are cylinder specific as to being random misfires. because it is cylinder specific, it rules out many probable problem components that would share operating ignition components and fuel components with the other cylinders.

basically, specific cylinder misfires need the fuel system checked from the injector to the injector drivers of the ecu and spark checked from the plugs to the tdc sensor of the dizzy.

i dont feel like explaining the reason why a misfire will be "DETECTED"? that is just to much typing for me. search on the operation of the ckp sensor and it should give you a good explanation on it.

not recieving fuel, spark, or both will cause a misfire to be detected.

others include,

egr, map, tps, mismatched fuel to vac lines, low and uneven compression, iacv, ckp sensor, tdc sensor, etc.

PS: what ecu are you running?

[sohcfreak97]

see now if u stated...check the injector and ignition components...it would have made more sense...instead of saying "check for spark" or "check for fuel", anyways like i said before...i would check to see what ecu u are using, if its compatible,timings, and it wouldn't hurt to do a compression check on those cylinders either

[superbluecivicsi]

Originally Posted by sohcfreak97

see now if u stated...check the injector and ignition components...it would have made more sense...instead of saying "check for spark" or "check for fuel", anyways like i said before...i would check to see what ecu u are using, if its compatible,timings, and it wouldn't hurt to do a compression check on those cylinders either

????

so, you really dont understand that the term spark and fuel applies to the ignition components and injectors?

i figured since the army and shop uses the term spark and fuel, and everyone else i know uses it, i figured it was a lamen way of saying check all ignition and fuel components. maybe the army should make a new policy in their armoured fleet and my shop to use the term ignition components instead of spark

[superbluecivicsi]

PS: isnt the jdm d15b an obd1 motor? assuming this is correct, you are running on what ecu and harness?