Sounds good I will check those and replace my valve cover gaskets as well.

Scoured the forums and found two guys with exact same symptoms/situation and both were fixed with injectors so I'm crossing my fingers. I will update when I'm done.

 

If the fuel filter's oe you could knock that out too.

 

Thanks. Did that already hoping it had something to do with the problem...

 

I said it in a couple of posts above, and I'll say it again. It's most likely your injector(s). Same symptoms and all. Send them off or get some remans and call it a day. Update us when you figure it out!

 

Already done...all six are on their way to Witchhunter!

 

Nice! I got some remans and they've been good so far, but after all the good stuff I've heard about WitchHunter, I wish I'd have just sent them there. Hopefully this will clear up your problems! Let us know.

 

Ok I give. I just re-installed the fuel injectors after getting them back from Witchhunter. All of the injectors tested good but the cleaning definitely helped as evidenced by the test results. I put it all back together and it fired up with no issues. Started better than before and ran better as well. Test drove it and let it sit for about an hour to try and duplicate the problem that occurred before (see original posts).

Started it after about an hour and it fired right up and idled fine. Started driving and I felt a little hesitation. I accelerated to clear it out and the CEL started flashing then went off. Still no idle issues though. Drove it a bit farther and the CEL came on solid and stayed on. Went home and pulled the codes and it showed P0302 Misfire Cylinder #2 and P0171 System too lean. It still has no idle issues and sounds/runs fine so I am at a loss. :redbrick:

To summarize I have done the following:

Replaced spark plug wires with NGK's
Three new coil packs
Checked spark plugs (New Densos) (no cracks, gap issues, fouling, water or oil)
Removed all six injectors and sent to Witchhunter (all 6 cleaned and passed)
Reinstalled injectors
Cleaned plenum, throttle body and MAF
Checked vacuum lines and replaced two cracked ones
Replaced fuel filter
Seafoam in gas tank and through plenum

Any suggestions or help is appreciated...

 

Dealing with this exact same problem right now runs fine when completely cold but has a miss if you start it warm. Im Finishing changing the injector tomorrow to see if that fixes it.

 

Hope it works for you...rough idle has returned as well so back to square one for me...

 

Did you check the spark plug gap? If its smaller than .044" that can affect the idle. Contrary to the mattress tag warning, you can and should adjust the gap. Even the Denso and NGK websites tell you so. But you need to be careful and avoid putting force against the center electrode.

 

There is a small electrical coil inside the injector. When it fails it can make a complete break or and intermittent separation and as it heats up, the coil become intermittent. It should worsen over time but theres a good chance this is injector related.

 

Checked the gap on all of the spark plugs when installed and recehcked when this problem occurred.

Injectors were all sent to Witchhunter. They were tested, cleaned and all replaceable parts replaced. Then they were retested. No issues with any of them so injectors ruled out as well.

The symptoms are back as they were...first start up of the day it runs like a champ at idle, under load, on the freeway you name it. As soon as you turn it off and let it sit for five minutes before starting it up again, the symptoms return. Bad idle, low power, chugging at low rpms and under load or acceleration the codes return.

People have mentioned the O2 sensor...When running my Torque app I did notice the #2 sensor goes to 0.0 v when this restart issue occurs. After first startup it is 0.6 to 0.7 v. I thought that once it warms up it goes to 0.0. Is this the case?

Might have to toss in the towel and take to a shop nearby. I'm out of cheap DIY fixes at this point.

I'm in Rancho Cucamonga, CA if anyone has any recommendations for a local shop.

 

Fuel pump. Mine just got replaced. Once it got warm the fuel pressure dropped. Hard start, sluggish, etc. have you changed yours yet. $95 at rockauto.com

 

Haven't but I'm hesitant to throw more money at this hoping to fix it. Not having any hard start issues even when the other symptoms occur. Starts right up.

Is there a test for the fuel pump? Would a bad fuel pump cause all of those codes/misfires?

 

Wow, I'm really surprised it wasn't your injectors. I'm even more surprised that injectors/coil packs/plugs and wires didn't fix the issue. I assume the misfire code you're getting is on one of the new coil packs? If not, I'd swap some around.

Update when you find the issue. I'm interested to know what it could be.

 

Yes its on the new coil pack and I was surprised and frustrated none of this fixed it. Not sure what to do. Looking for a local shop that can troubleshoot it as I have run out of cheaper DIY fix solutions...

 

Electrical gremlins are tough to find but I am still thinking its either fuel or exhaust related. Hows you CAT?

 

Just putting that back up there so it doesn't get lost in the chatter. Sorry I'm not sure of the answer on it.

Dude. Had all my fingers and toes crossed for you. I just did a whole lot of head scratching with the 96. Worth it in both the experience and having figured it out with minimal unnecessary out of pocket which is a good thing. Lint just doesn't seem to spend like it used to.

So...what goes into signalling the coil to fire #2? Without knowing what I'm doing I suppose that'd be the next question I'd ask myself.
I'm not in your area so I can't help you on the mechanic question.
Good luck and let us know.

 

The O2 should not drop to 0v and stay there....it should alternate repeatedly from between less than 0.4v to more than 0.55v after running the engine at 2500 rpm for 90 seconds per FSMs.

 

Yeah but does it even matter for the #2 O2 sensor? Thought that one wouldn't cause the fault...Besides why isn't it throwing any O2 Sensor codes if it's failing?

Thanks Habanero. Someone recommended a local Toyota only shop, think I'm gonna try them. I've done a lot of the initial troubleshooting and replacing stuff so should be a little easier to nail it down. Can't afford for it to be down much longer. Someone sent me a way to diagnose the MAF so I'll try that. We'll see.