joeflem

Don't know about the CAT. No weird smell or overheating and no cat codes thrown...


Really starting to worry this is a valve issue maybe?

habanero

My 96's cat (248,000 miles) didn't throw codes either, but it was bad. My symptoms included pinging and some power loss under load. Also the sulfur smell when I nailed it with the back window down.

Go back to the misfire. It runs good first time, would a valve problem do that? If you are getting a misfire and you've replaced the coils, plus switched them with a known good......what signals a particular coil to fire? If you're still only getting no. 2 what goes into that particular coil firing? Plug. Wire. Coil. Sensor......I wish I had more knowledge. All I know is there's a way to test lots of things and specs available for them.

I want this fixed almost as bad as you do because I'm intrigued by it. It would be interesting to get to figure out. Even if I ran away screaming something fun would be learned.

joeflem

Thanks for talking me down You are right, can't be a valve and shouldn't be a head gasket. Took it out this morning totally cold and it ran like a champ. Acceleration and power was good, idle perfect and no codes. Took it up to highway speeds, up a hill and everything worked fine.

Then I stopped at the gas station to fill up and turned it off. After I finished filling up I started it and there it was. Rough idle, chugging and as I drove back home up a very slight incline I got a flashing CEL briefly then it went away and a solid CEL came back on. Pulled the codes and it was again P0302 Misfire. Good news is I changed two broken vacuum lines and the PCV valve and have not seen the P0171 Too Lean or P0300 Random misfire codes at all. It has been pretty consistent with #2. I also started it with the radiator cap off and saw no bubbles so along with no wet spark plugs, white smoke, sweet smell or milky oil I'm thinking no head gasket issues either.

That's what drives me nuts. If I drove it off that first cold start, I could go for miles and miles with no problems and a great running car. As soon as I stop and turn it off even for a few minutes, as soon as I restart it it's running like s**t and throwing that code.

I logged the realtime info from both trips this morning on my Torque app. Maybe I'll post the results later and someone can look at them. I'm probably gonna drop it off at that shop this weekend though and let them at least diagnose it. I'll keep updating. Thanks.

dspin

Did you put the number two injector back in the number two spot after it was rebuilt/Checked. I just finish swapping injectors last night and it appears to have fixed my problem (2 hot restarts so far with no rough idle). Which sounds exactly like what your dealing with. ie

-Only happens when started after it's been warmed up
-Miss on same cylinder

The weird thing is my resistance on the injector I pulled was 13.7ohms which is in spec. I'm gonna try to throw it in the oven tonight and see if the resistance changes once it's been heated and as it cools. I'm thinking that there is something failing in the injector as it cools after being heated.

If it's happening on the same cylinder I doubt it has anything to do with fuel pressure, CAT, or O2 sensor as I would imagine all those would cause a random miss.

j-man

things like this are enought to make a grown man cry! I just went thru all this with my 2000, and the symptoms seemed the same.
Things i replaced/swapped from a running motor were:
maf
front 02 sensor
coils/wires
throttle body/tps sensor
efi coolant temp sensor - can make the motor run lean if they go bad - causes similar symptoms
all 6 injectors - also sent to witchhunter...which were fine.
checked all vacuum hoses...every darn wire on this thing....

it ended up that the main Toyota ECU was bad, and it would only act up when it was warmed up. I swapped it out with another identical one just to check on a whim...and wallah...problem cured. I just bought one on ebay for a hundred bux....

joeflem

No it wasn't the same injector in that cylinder as I didn't mark them when I sent them off to Witchhunter. They test them all for resistance and function so they should be fine. I don't think this is an issue with the injector itself. Let me know what happens with yours though...

I am ready to cry! I'm glad you fixed yours though. Just can't bring myself to throw more money at it without some diagnosis. MAF, ECU, O2 sensor...could be another $300 or more and it still might not fix it. Thanks for the info though I appreciate it. Think I'm gonna leave it to the pros.

rworegon

joeflem, hoping you post up the fix after you take it in....it will be a good reference point for this issue.

joeflem

I will. Thats what sucks about this issue is there are a lot of other threads about it but not many that end with a solution. I'm very appreciative of all the posts to this thread though with other's solutions. I'll post the results of mine for sure.

joeflem

After all that it was still an injector...So I am spending about $500 for something I already did. Pretty bummed. Mechanic was really cool and troubleshooted it for free until he could not find the problem. Compression was awesome and no coolant leaks which was good news. Determined there was no fuel going to #2 cylinder. Thought it might be the wiring to the injector but only way to find out would be to pull the plenum which was $255. It was already there so I let him as I need this resolved. Checked the #2 injector and it was like 3 ohms resistance. So after all that the coiling in that injector was failing all along and I put it right back in #2.

What are the chances I put the same injector in #2??? Crazy. He's gonna put a OE injector back in and is 100% sure this was the issue. Said the truck runs and sounds great otherwise. I'm out $500 plus what I already spent but as he said at least I have taken care of a lot of the issues that might come up anyway. Think I'm gonna pull the coils and return them though and maybe try to recoup some of my money.

habanero

Wow! Seems crazy unlikely you'd end up with the same injector in #2. At least you've gotten some great reassurance about the health of your truck. Considering what you've put into it and what you didn't you were reasonable with what you did. To think you had it, that may be a DOH moment but it should make you feel good, too. You had it!
Well, I don't know about you but I learned something. Thanks!

joeflem

Thanks for your help and advice. I did learn a lot and I think the stuff I did will be good for the truck in the long run. Does suck that I could have just pulled the upper plenum off one more time and checked that #2 injector and I would have been less in the hole but this way I did get reassured about the overall truck especially the cooling system being good to go. Just hope this is the last mystery for this 4Runner and maybe this helps someone else.