xxxrider

i have a 1996 toyota tacoma 4x4 with the 3.4 6 cyl and every few weeks or so it will misfire and the check engine light will come on but it will only misfire for less than a min. tonight i was on my way home and it started to misfire and it hasnt in like 3 weeks and it misfired for like 10 miles untill i went home.about an hour later i started up my truck and it was fine What can cause this to happen?

Mr. Bob

Well... starting simple how are the spark plugs?? Rest of the tune up?? How many miles on the truck?? Original spark plug wires??

xxxrider

all of the spark plugs are new and looking good, all the wires have been replaces recently, the truck just turned 150,000 miles what would a tune up be consisted of? could it be something that is inside of the injector? i also ran a bottle of injector cleaner to try to help but that did not work

xxxrider

anyone else have this problem?

xxxrider

bump anybody?

acid_burn

coil pack?

MTL_4runner

Definately sounds ignition related (you might want to get the codes read even if there is no CEL since codes can be stored in the ECU without showing a CEL). I would pull all the plugs again and check for damage during install (it has happened even to the best of us). You said you replaced the wires (I hope with OEM or NGK). Finally you should test the coil packs, do a search and you'll find the procedure along with resistance values.

You should also clean the throttle body, replace the air filter and change the fuel filter if you haven't already.

boraxman

I had this problem shorly after changing my plugs. Well turned out to be a brand new defective plug. I would replace it weater it looks bad or not.

funrunner91

with mine it was a spark plug, but later on it started acting up again, the hoses to the egr value dry up and crack.....real cheep fix also the all the intake hoses and filter

MTL_4runner

The 3VZ is totally different, no EGR on the 5VZ

funrunner91

oh sorry about that....i'll shut the heck up

MTL_4runner

No worries man, input is always good.

xxxrider

but it only happens occasionally if the plug was bad it would always be misfiring....i check the timing and it was very far behind but my truck runs great

MTL_4runner

You need to check the timing via the OBD II, the timing can't be changed either because it is computer controlled. You condition can be several things and you need to go though them one by one as outlined above to find your problem.

boraxman

Not necessairly, there were times when mine ran fine...but it would always end up "missing" on the same trip.

xxxrider

i can tell when mine starts to misfire because i can feel the truck almost rocking back and fourth and when that happens the check engine light comes on and then i will clear the check engine light and it will only come on when i can feel it misfire again so im pretty sure that it is only misfiring when i feel it do so and the check engine light comes on

darth brian

i think you need to swap you motor for a more simpler reliable 4 bangin' 22R

8422r4Runner

Do you have access to a timing light?
While they are normally used to check the timing they can also check the spark plug wires and coils for spark.

You hook the two leads to the battery and the other lead on #1 to time it. But the light will flash on all the wires. So I suggest you hook it up, start the rig and hold the trigger so the light flashes for at least 30 seconds. Spark plugs wires will leak spark, but do not always do it every time, that is why I say at least 30 seconds.

If at times it does not flash, then the spark leaked or the coil never sent one down the plug wire. If it always flashes, then the spark plug may be at fault.

You can test all the wires that way, even the coil wire.

rugerm44

What kind of plug wires did you put on it?Check the resistance of each one while someone else bends and flexes them.Those aftermarket plug wires are not all there cracked up to be.What kind of plugs are you running.The 3.4 dosent like those bosch plus four plugs.Mine only runs well with ngk or denso.It calls for dual electrode plugs on the 3.4.What kind are you using?

xxxrider

i am running the denso plugs and wires the other day i replaced the 5th cylinder plug and i am just waiting it out to see if it is going to happen.....it would be easy to find if it happend all the time but since if only happens like once every few weeks it is really hard to trying to find the problem


but i will do the timing light thing....the only problem with that is like i said before it only misfires every few weeks so i dont know