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All 4 cylinder misfire?

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ohTONYoh

10+ Year Contributor
173
6
Jul 29, 2012
yorktown, Virginia
My check engine light is on, did the codes and its multiples cylinder misfire..1,2,3 and 4. I changed the ignition coil and put platinum plugs in, wires are fine. You can here no misfire and the car drives perfect.

Though, the engine was rebuilt. Im thinking the guy i got it from had the cylinders bored and put the original pistons back in. You can here knock when the cars warming up, but it fades away. Could it be the knock sensor? Im confused.. help or answers would be appriciated.
 
The code sounds like an issue I had with my old n/t, turned out to be a ~$20 crank sensor. As for the knocking sound, is it really a harsh knock or more of a tick? If it's coming from the valve cover it's just lifter tick, which is what I would suspect since it goes away.
 
Thats what i thought, when i first turn the car on in the morning, the knock is somewhat loud, but it almost completely goes away. Would that still be the lifters? Maybe need a tune-up?
 
Depending on how many lifters are stuck, and how much play they have, definitely. You said the engine was recently rebuilt so I'm hesitant to say it's something internal. It's possible it could be an exhaust leak too, both are pretty common on DSM's.
 
Well i just recently put new gaskets on the entire exhaust system, torqued the bolts. I have a feeling the lifters are not the problem. You can only here the knock when it idles, when you press the throttle it sounds like a brand new engine.
 
It's just a matter of cleaning them, I'm not sure if the removal process is the same between the 4G63 and 420A but it's maybe a couple hour project. I've never heard of sticking lifters hurting anything, but they are annoying as hell.
 
I really hope its not anything serious. The check engine light just bugs me when i go to the cars and coffee car shows haha. Ill have to look into testing the knock sensor.
 
Oh, sorry I thought I had touched on that.. My old 420A did that too, check engine light for "random misfire" with no actual misfire. After throwing $1000+ of parts at it, it turned out to be a $20 crank angle sensor. If it runs healthy I would look into that first since it's one of the cheaper/easier things to do.
 
No, im testing to see if it is the sensor, if its not, then i will check the lifters.

I will most likely just get a new sensor because i cleared the codes, and its come back twice with all misfires still.
 
Will do, ill have to do it when i change my speedometer gear inside the transmission. Have to take the entire thing out just to get to the tiny tiny gear.
 
Will do, ill have to do it when i change my speedometer gear inside the transmission. Have to take the entire thing out just to get to the tiny tiny gear.

take what entire thing out? the trans? because thats not the case if your changing the speed sensor. and a misfire can happen if your timing is off too since the motor is freshly rebuilt
 
Ive changed and tested the speed sensor. Its the gear actually inside the trans.

Im just going to give it a full tune-up this week and see what ends up changing.
 
how would you check the crank angle sensor? when i bought my car it wasnt running, i put a new crank angle in and it started up, could it have gone bad again?
 
how would you check the crank angle sensor? when i bought my car it wasnt running, i put a new crank angle in and it started up, could it have gone bad again?

Yes, if you have some sort of voltage check tool, just put it on the main wire connection that plugs into the crank angle sensor. If you have voltage and it still wont work, then the sensor is probably bad.

Mine has gone bad twice. The replacment sensors have like a 15,000 mile lifetime i believe.
 
Yes, if you have some sort of voltage check tool, just put it on the main wire connection that plugs into the crank angle sensor. If you have voltage and it still wont work, then the sensor is probably bad.

Mine has gone bad twice. The replacment sensors have like a 15,000 mile lifetime i believe.

Ok well my question is, is the test still going to help if my car doesn't misfire until I've had it running for a bit too long, 30+min, then it starts to misfire and run like crap, I shut the egnition off and turn my car back on and it runs fine again for like 5 min
 
Ok well my question is, is the test still going to help if my car doesn't misfire until I've had it running for a bit too long, 30+min, then it starts to misfire and run like crap, I shut the egnition off and turn my car back on and it runs fine again for like 5 min

Ohh okay, ive had no experience with that.
I dont know if that would be injectors, ignition coil, sparkplugs, sparkplug waired or whatever else it could be.
 
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