gap81

and various 0301-0306...misfire codes. They are different each time. I cleaned out the TB, the MAF and replaced the air filter and it ran fine for 6 days...then started stalling again. No lean running or 02 sensor codes, just random misfires. I can't figure it out. I think I hear a vacuum leak but can't find it. Could that cause these symptoms? Truck runs fine otherwise. It just dies when I slow to a stop. It may do it for 5 stops in a row, then not at all....and so on. I guess I'll try plugs and wires tomorrow. Anybody ever have this? Thanks.

ff11979

ive got a very similar problem and cannot figure it out. please write in if you have any luck finding out.

gap81

will do....hope to get to it today, if it ever stops raining here.

MTL_4runner

Do you have an OBD reader so you can get the codes?
Hopefully yes in this case.

Did you get all these codes at once or just one or two at a time?

P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0305 Cylinder 5 Misfire Detected
P0306 Cylinder 6 Misfire Detected

Was anything changed recently before this started happening (ie did someone work on the truck at all, timing belt maybe)?

Diagnosing:
Misfires can be tough to diagnose if they are random (ie you have a P0300 along with the P0301-P0306). First thing I would do for sure would be to change the plugs if you have not already (OEM NGKs or Densos only). The second thing I would check is the timing belt (remove the cover and make sure all the timing marks line up as you rotate the crank pulley and that the timing belt doesn't have too much slack in it). There are a few other places to start after, but I'd suggest resetting the CEL after each time you change something to see if it was fixed or if new codes return.

http://www.deserted1.com/FSM/Repair_...e/cip0300p.pdf

gap81

I have a code reader. I get the 0300 along with a few of the 0301-0306 codes...different each time. I just changed the plugs(ngk) and wires as well. Sounded great at first and idles like a champ. Unfortunately the problem is worse now. As soon as I put it in gear...it dies. I can't get 10 feet under load. I'm convinced I hear a leak but can't find one anywhere which makes me think the worst. Nothing was changed recently. Check engine light was on and off for a while, then a rare stall, then stalls only when warm. It might be the IAC valve I guess but I'm not sure how to remove the whole throttle body to clean it. I'll have to get a haynes manual tomorrow or just take it in to get it done. :pat: Man I hate failure.

gap81

Oh yeah...had basicly a whole top end rebuild about 10k ago...timing belt, water pump, harness, gaskets...the whole deal.

gap81

update...after letting the truck idle for 30 minutes or so, I tried to take it out again. Seems to have "adjusted" itself a little. I drove for about 20 minutes and it only stalled a couple of times. Way better than 1/2 hour ago, but definitely not fixed yet.