8422r4Runner

When using the timing light, grab plyers or something to insulate you from shock. Use what ever to wiggle the spark plug wires as you test them. My thought is maybe the wire has to be laying a certon angle for the miss to happen. Wiggleing the wires may help cause the miss.

Make sure you insolate yourself from the wires, if the spark is leaking it will/can jump to you. The zap wont kill you, but your arm my be worthless for 10 - 20 minutes.

MTL_4runner

There is lots of info on this problem on YT.
Do a search and I bet you'd find stuff like this on here:
https://www.yotatech.com/forums/f2/1996-4runner-v6-check-engine-light-misfire-31969/
https://www.yotatech.com/forums/f2/3-4l-missfires-sometimes-68062/
https://www.yotatech.com/forums/f16/coil-pack-replacement-3-4-symptoms-slight-skip-results-check-your-coil-packs-today-58255/

The #5 cylinder is on the coil pack side (no plug wire) so all indications would point to that as a culprit.
Cylinders #2, #4 and #6 are on the wire side.

......try switching coil packs and see if the problem moves to another cylinder.

xxxrider

i will try switching the coil packs and see if anything happens but it has been a few days now with the new spark plug and it is still running fine ill keep you guys posted

rimpainter.com

Hey Jamie, I thought some/all Taco 5VZ's had EGR.

Now I am curious.

MTL_4runner

My bet would have been the plug or the coil pack so if a new plug fixed it then great.
I thought it was still giving you problems.

MTL_4runner

Ok Christian, stirring up trouble again.
To be honest, I think you are right on the early versions of the 5VZ.

xxxrider

well it has been about a week now with the new plug and it is still fine but it usually only happens every few weeks or so......but i will keep you posted on whats going on

xxxrider

cylinder misfired right after i posted the reply....i spoke to soon i guess.well today i am going to switch around the coil packs and see if any of the other cylinders misfire. if the coil pack is bad is it ok to pick one up from a junk yard, or should i invest in a brand new one?

darth brian

if it were me i'd get a new one. you never know if your geting another busted one. reassurance is better that saving a few bucks.

Machine

X I had the same problem w/ my yota misfiring. I tried everything sparkplugs, all the coil packs, wires, fuel filter, fuel,& etc.
When it came down to it I noticed my belts were not aligned. My crankshaft pulley was loose. I took apart the whole front end of the engine and to my suprise the timing was a whole quater off. I realigned the timing belt to the proper lines and proceeded to put everything back together, put some red LOCKTIGHT on the pulley bolt and cranked her up and it ran perfect and since then have not had a problem.
Just my .02...

Does it misfire when you rev the engine up between 3200-4700 RPMS?

xxxrider

my crank shaft pully likes to come lose too it has happened a few times even with red lock tight so my timing is probably off :pat: i checked my timing a few days ago and saw that it was pretty far behind....it is all coming together now how hard is it to realign the timing belt?

Machine

Not hard at all just really time consuming it took me about 4hours to take all the pulleys and the front of the engine covers apart, fix it and put it back together with all the right tools and the know how. once you take everything off the front of the engine and you can see the timing belt its fairly easy.
With everything off and you can find the timing marks on the pulleys
take the crank pulley and seat it back on, **make sure the key slides back into the groove** [this is how the timing got way off... the bolt came loose and the pulley had enough play in it to move away from the key and would free spin]and tighten the pulley enough so you can stick a skinny breaker bar or something similar through the crank pulley and slowly turn it and see if all the hash marks line up (i believe there is 3 marks) they should with no problem. if they do then take the crank pulley back off and put all the covers back on, replace the pulleys, belts, and so forth. crank and rev it high. it should run extremely smoother than you are use to.
If each one of the hash marks are off then you will probably have to take it to a shop.
Hope I could help...

MTL_4runner

This would have been some good info for diagnosis. Who did your timing belt? Whoever it was, it sounds like they did not torque it properly or that the threads in the crank are stripped. Crank bolts don't just come loose again by themselves when torqued correctly.

Quick way to check is to pull the top timing cover off. Then put the crank at TDC and check that the cams are in line with their timing marks (remember the crank does 2 revolutions each time a cam does 1). If this is indeed the case and your pulley did spin like Machine's did, you better pull it all apart and check the pulley and crank for damage.

Here is the timing belt procedure:
http://www.4x4wire.com/toyota/maintenance/timing_belt/
http://www.lieblweb.com/tacoma/Mecha...cans/index.htm

xxxrider

everything is fine with the crank i talked to my buddie who use to be a master mech. at a toyota dealer and he said that it probably is not that and that he thinks it is a valve is messed up but he doesnt know for sure. tomorrow he is going to do a compression check and see if it holds

Mr. Bob

Hey xxxrider... you may want to re think your sig.... you are the one having troubles with your Toy while my bronco runs just great

I would like to see how switching the coils works... Its my guess the miss will follow the coil.....

darth brian

ohhhhhhhhhhhhhh snap!

AJatx

I had intermittent misfires on my set-up after I changed the timing belt. It turned out to be two cracked sparkplugs (brand new from the dealership). The ceramic portion had small hairline cracks that lead to inefficient spark.

xxxrider

that was my first thought too but after replacing them i kind of ruled that out because the problem the problem doesnt follow the spark plug when i switch them around....i just need to wait to get the compression test and see if i have a leak in a valve. if the compression is fine then i guess i am just going to have to get new wires and new coils again.... my brian hurts

xxxrider

switched the coil packs and waiting to see what happens..

Mr. Bob

am interested to hear how this goes!