EToy

Hey fellow wrenchers,
My 92 3.0 runner is having engine troubles and I am stuck. I apologize in advance for the long post, but wanted to give as much info as possible.

I changed the timing belt a couple weeks ago and put everything back together with no problems. Took a 500 mile trip with no problems. Then last Tuesday, i was sitting at a light and all of a sudden the engine started running really weird and had a hard time accelerating.

Now when the engine is idling, the engine shutters every couple of seconds, and at the same time a different exhaust sound comes out (almost like it suddenly "puffs" the exhaust out). If I watch the tach, it drops down about 100 rpm when the engine shakes.

I took it into my local yota specialist and they put an exhaust gas meter on it and said my HC reading was something like 1400ppm. They thought it might be an bad rotor so they changed that and it seemed to help a little bringing the HC reading down to about 900.

Other relevant info. Two month old wires, and NGK spark plugs. Running headers (downey?) and custom exaust to the tip.

My mechanic suggested taking the Air intake manifold off and checking the valve clearances? Does this sound reasonable?

I'm out of ideas, can anyone think of anything?

Bumpin' Yota

my blind shot in the dark....

could the timing belt have jumped a few teeth?

AgRunner06

Those "puffs" are the engine missing. The mechanic that did my headgasket job told me that was normal because the a$$hole didn't want to figure out what was wrong with it.

Definitely check your timing. I was having the same symptoms as you and it ended up being the TPS. My timing was off because my TPS was bad. After replacing the TPS I still had some problems because the throttle cable was too tight.

If you timing is correct still have them check the TPS. It runs almost everything on that motor.

Then you may want to move on to the fuel filter. There is quite a few things that could be the problem.

Does the "hard time accelerating" feel like a hesitation right when you first step on the gas? Do you have to push harder on the gas to then get it to go?

I would check the easy stuff before you start tearing into the motor.

Here's my list:

1. Timing
2. TPS
3. Fuel filter

I hope this helps.

Good Luck

EToy

Hey guys,
thanks for the ideas. One thing I forgot to mention is that my mechanic already double checked my cam timing (he suggested the belt may have slipped) and overall engine timing before replacing the rotor.

93_runner06, yes, by" having a hard time accelerating" I mean when I tried to take off from the line the truck just spit and sputtered and didn't want to get going. Once I got the rpms up, it seemed better (although it seemed I could feel the miss less often in the high rpms also.)

I considered the fuel filter since I don't know if the previous owner changed it, so maybe I'll look at that this week before checking the valves.

Thanks for your input, much appreciated!

lunatic14r

if its mising all the time i would try to find what cylinder is causing the miss try pulling 1 spark plug wire at a time and see if the that cylinder drops of if it does not than thats the bad cylinder and you can go from there.
even that they are new you could have a bad plug or wire.
good luck

EToy

lunatic14r ,
Not sure if I fully understand. If I pull each wire off one at a time, what should then engine do if it's the bad cylinder? How should it act if it's not the bad one?

Thanks!

E

lunatic14r

what will happen if the plug wire you pull is good the engine rpm will drop some you will here a change and it will run worse if it the bad cylinder the engine will sound the same and run the same with no rpm drop.

Travis

I had the same problem a while back - rough idling -. The dealer mechanic replaced the timing belt and put in new plugs but the problem persisted.

After some research, I learned that it was the computer getting the fuel mixture wrong. To fix this, I disconnected the battery for a couple of hours allowing the EFI to reset. Then I drove normally for a few tanks as the computer recorded new data. Seemed to work, now my truck idles normally.

I'm not sure if this will work for you but it amazes me how many people overlook this possibility.

AlixTheRunner

I had almost exactly the same problem, and just got it fixed at my mechanic. 2 things wrong...

1: Reed valve...I looked @ it once he pointed it out, and it was cracked. Where is it you say? Right behind the EGR valve. The plastic cap on the back part of it was cracked. Pinching it closed fixed the gurgle (Mine was especially noticable when the engine was reviving down...

2:Valves too tight. After pulling a few wires, I found that 2 of the cylinders were not firing at all, so I was essentially running on 4 cylinders. My mechanic pulled off the throttle body, readjusted 5 of the valves, and it Purrrrrs now. VERY NICE...

You also might check the vacuum hoses to make sure they're connected...

only bad thing was that the Reed valve was $180 ouch...

Good luck...

Babypig

I would check the rotor again and possibly the distributor got moved when putting it back in. I had two rotors go bad in one day. Same kinda problem, with a sulphur smell as well. Make sure the rotor is toyota brand as that seemed to be the problem on mine.

EToy

Just happened to be checking out my subscribed threads and noticed that I never posted the solution. The problem turned out to be a bad ignition coil. After all of the trouble I went through it turned out to be a pretty cheap part and a 2 minute fix.

E

SoCal4Running

Sounds like an exhaust leak at converter to me.

Shoorty911

if i was getting a spark from the rotor cap to the wire, could it be an ignition coil....i think cylinders 4 and 6 are misfiring since i pulled both wires and saw no difference in idle or rpms..

EToy

It's possible. My coil seemed to work some times but not always. So there would be a spark at the wire sometimes, but when I would drive it there wouldn't be.

Since it's such an easy part to change, and it's relatively cheap, it would be worth a try.

E