I've posted on another thread, and even after reading as many existing threads as I could possible read in the last few days, trying much of what's suggested to others?.....I'm STUCK!

Mine is running like a dog, after warming up. I've pulled the TPS(runs smooth-probably cuz it's DUMPING fuel in there, eh?lol-, but when you step on the throttle, it still hesitates and bogs out....Hearing a bit of knocking and ticking, too, whether the TPS is connected or not...but no knock or tick when it's cold, only after warming up).

Pulled the Coolant Temp. sensor; NO change, at all.

Pulled and plugged the EGR; NO change, at all.

Sprayed Carb Cleaner, like a bath, on every vacuum line, throttle body, etc.; NO change

After warming up a bit, it begins to sputter and knock, hesitation in throttle reaction, ....basically, runs like CRAP. When driving, acts like a dog if you let out clutch slow, giving it very little gas, and wont take off till 3000rpm or so, then, as I said before, BAT OUT OF HELL. If I'm driving in 3rd or 4th, keeping it at a low RPM, it's as though it's missing(sputtering along-Hesitating, but nothing dramatic).

I'M VERY strapped, and I can't afford a full diagnosis, or the potential cost of getting raped by the suggestions, thereafter(which are usually something like "OH, yeah, you need a TPS, MAF, Full top end rebuild, yadda, yadda, and a lotta'mo'yadda".....and, especially considering it's running like a CHERRY, when cold?....I'd KNOW that would be CRAP).

Where should I go from here, .....PLEASE?

PS> Throwing NO Codes(yes, engine light is working)

PSS> o2? CAT? And, ...how would I check these?

 

Check your cold start injector. My 3.0 ran ok when started cold, but once warmed up it ran really rough. Turned out to be a faulty CSI that was dumping fuel continuously instead of only at start up. That is easy to check and hence rule in or out. Search for "cold start injector" as there is some good info re: testing.

Good luck,

WJ

 

Hey Joe,

Sorry for not responding sooner. My mom had an appendicitis, emergency appendectomy and then wound up back in the hospital again. She has only me to care for her when stuff happens, so I've been totally pre-occupied with that and work 70+hrs. a week(I've been driving my CRV and ignoring the 4Runner).

Anyhow, thanks for the input. I've just purchased a multi-meter, to check sensors, since this is driving me insane at this point. I pulled the CSI plug, just for a quick check, but no results. I will check it properly when I have time. HOWEVER, now my Water Pump is leaking(That's all I can guess, since when I look up from the floor, it's running on the bottom of the housing, then dripping down from there...Just put a brand new radiator in, too).

So, I'll be doing that, as well, and now I'm thinking, with 123k on this timing chain(minimum), I might just want to tear it down and do a mild rebuilt(valves, etc.). Yet, again, I figure I'll still have this hesitation issue after doing a top end/timing chain rebuild, so I'll just have to go through this engine one thing at a time(process of elimination, lol).

I'm not sure about my CAT or O2 sensor, but the O2's not throwing a code, so not sure that's the problem. Also, when I pull the plug on the TPS, the idle jumps(of course), but the hesitation and 'STANK FROM THE PIPE' is still there(guessing it's running rich).

There's nothing I'm not willing to do, and I've replaced all kinds of suspension parts, new warn hubs, arms, rotors, done seals and timing belts before on cressida's and a Camry, but never ran into a problem like this with a sensor. Neither have a had an issue like this, where it runs fine for about a minute, full power, then as it hits a certain temp, KAPUT, running like crap, lunging, hesitation until 3000 rpms, then BAT OUT OF HELL AGAIN! I've been searching these threads, I've tried many things, but I'm just not able to figure this one out. Even a decent mechanic I know(who checked it for free), can't pin it down(no codes, no obvious issues-egr, vacuum leaks, etc.)

Sorry to ramble on, Joe, I'm just really frustrated and overwhelmed with life outside of toyota repairville! lol. tHANKS AGAIN for your input.

 

Hi Chef,

Sounds frustrating, and I am sorry to hear about your mom, hope she is ok.

I had a similar rough idle problem that turned out to be an easy fix, I hope yours is too.

A Toyota dealer mechanic told me to test the cold start injector as follows: unbolt it from the intake plenum, but leave the fuel line and electrical connection in place. Place it in a clear jar and have a friend turn the key to start the truck (the engine should not actually start unless you block the csi port in the plenum).

The injector is supposed to spray briefly then stop. If it continues to seep, it is faulty, and the continuous dumping of fuel from it makes the engine run way rich and you can smell it in the exhaust. New ones run $130 from Autozone or $200 from the dealer.

Hopefully that is it because it took me less than 10 minutes to replace it, although the diagnosis was a long frustrating task.

The coolant leak has me worried though. Rough idle with coolant loss can point towards a head gasket problem. That can also cause a rough idle. I hope it is the easy fix for now, sounds like you have enough on your plate.

Good luck Chef,

WJ

 

Well, I wanted to update all the good people on this site. Thanks for the input from many of you.

Since posting this original message, I've learned MUCH as well as realized, MANY THINGS can come into play in regards to a open/closed loop issue-- cold or warm issues-- full warm up issues, etc., etc., etc. So, here's what I've done.....

First, I replaced the O2 with a OE Bosch, which did plug right in....seemed to smooth it out in comparison to the ORIGINAL(265k mi.) o2 sensor. HOWEVER; NOTTTTTT GOOD ENOUGH in open loop after fully warming up. I'm not bashing Bosch.....Just noticing a general consensus about USING OEM TOY PARTS! I replaced the O2 with a Denso OEM(By the way, if you go to the Toy Catalog site, pull and print a price, the local dealer might do for you what they did for me.....They asked for the price sheet and then charged me 132.00 instead of 187 with tax) After the Denso o2, it's RUNNING 90% better after running kinda crappy for the first 3 minutes or so of open loop. After warming up a bit, IT PURS! However(again, lol); When I kill the engine, go shopping for a half hour/hour, I start it up and it bogs again, just for a lil bit, then once on the road, it's back to full power. I do still notice a TINY miss(I'm guessing that I need to adjust the valves after 265k mi. without a single tweek, eh?lol). However, I'm still a bit baffled by this short period of time-open loop issue.....?

I've replaced;

Denso Plugs, ...New Wires, Cap and Rotor, Half the Vacuum lines(getting the rest asap), coolant lines, fuel lines, fuel filter, ---brand new Radiator (needed it bad), Water Pump and T-stat---, New Denso o2 from dealer, New Coolant Temp Switch, Ohm tested every Sensor I could think of(AFM, CSI Time Sw.[ weird reading on this....50ohm above 86*F, and 122.9ohm on ground reading-- FSM said 60-90], CSI, TPS[need to double check that] and checked my timing, it's at 8*, not 5*....But when I turned it back to 5*, before the Denso o2 sensor, it acted, well, like a WITCH! LOL. I'll try adjusting that back to 5* again, today.

Seafoam; Did a 1/3rd can in PCV and 1/3rd can in Brake Booster to Intake...Smoked like crazy, both times, and it seemed to help(I had the old OEM o2 sensor in for that treatment, and even though the thing was TOTALLY shot, my truck actually didn't drop to 300rpm any longer at idle. However, noticed smoke coming from the collector area(might be a crack--I'll inspect when I put the new gaskets on, today) and smoke coming from some welds in the pipe, just behind the collector(I guess the PO tried to weld up some rot or something?)

Anyhow, I just wanted to recommend that anyone having these open loop issues check your o2 Sensor. I also, personally, would recommend buying OEM, Denso or Aisin parts whenever you can afford it(on crucial components, of course)....It sure could have saved me several hours of PULLING OUT MY HAIR! Now, I just need to figure out why it's having this initial open loop drama. I would think that valves being out of adjustment would cause a problem throughout it's running. Could someone clear that up for me? Either way, it's time to check them and replace the Valve Cover Gasket, anyhow. I'm going to replace anything I can without rebuilding, watching carefully for ANY sign of burning oil or coolant.....but so far, it's running fairly perfect to most of my friends older Yota's.

PS> If my readings for the AFM or TPS or CSI Time Switch aren't within the specs of the book, is it DEFINITELY a sign of an issue with said item? I've not checked the Coil or pickup yet, but I wouldn't think they'd only mess up for a minute of two of open loop, ...would they?

Thanks to anyone who can offer any tips or insight.

 

Just cause I'm looking into HOW IT GOES BACK TOGETHER, and no one really knows the answer, yet there are many threads talking about it's effects when it goes out...

Idle Air Controll Valve.... IACV thanks to toyota4x4907 I know what the part is but no real clue how to fix it....

Do a search of IACV or the whole name and see if others ideling problems match yours

Best of luck

Repo

 

Hey Chef, glad we are linked up. It does sound like we are having similar problems. Does your idle and hesitation work itself out once the truck is warmed up? My problem ONLY happens during the 1 to 2 minutes of transition between cold and warm engine temps.

I purchases a Haynes manual and did some reading on the EFI system. I highly suggest you order yourself a copy of the manual. There are a number of components in the EFI system that regulate air/fuel mixture depending upon engine temp. There's an Air Valve that controls the amount of air entering the engine when the coolant temp is low. In addition to the cold start injector that WrenchinJoe mentioned, there's a cold start injector timer switch that controls how long that cold start injector is operated. Any of these 3 components could cause the issues we are seeing.

Unfortunately, I am totally swamped with projects and my truck is not my daily transport so getting this issue fixed is pretty low on the priority list. If you want, shoot me a PM with your e-mail address and I'll scan and e-mail you a copy of the EFI section of the Haynes manual.

 

Did any of u guys end up resolving your problem??

 

Not sure how is the problem, Ben. I started this thread 3 years ago? That was another motor, altogether. But, I believe one of m y issues was the IACV.... Another few things I replaced were the TPS, o2, CTS, ...... Swapped in an 88 ecu from a yard that was mismarked as 87.... different knock and o2 readings due to what the 88 ecu wanted out of the injectors (diff impedance in 88+), so it was running constantly in open loop due to the CEL's..... Swapped in the orig. ECU again and it seemed to stop bogging after warm up.....

HOWEVER, my problems had just begun as I suffered through a moronic rebuild by a shop who fuggled up even the bore, didnt replace a single valve or guide, lazy springs, bad leaks all over and eventually found a cored out block bolt hole for the top right timing cover bolt that goes through the alternator bracket... THAT WAS IT! Tore it down and rebuilt it myself..... it purrs. MOSTLY! Haha....

Now, upon warm reatarts, its idling down for short periods to 400-500rpm, thwn comes out of it within a min or two. (20 seconds if I stomp the skinny and bolt right off out the lot.....Still searching for that gremlin in my spare time, and I will do a full write up and P.O.E. in my build thread, when the time comes, SOON!

Been having issues with gurgling in the dash and the heater taking a while to get hot..... which it eventually does, lol.

Cant complain,.... I can run my R12 resto'd A/C system in 100*f weather on high and never overheats or misses a beat..... just a lil bogging down drama on hot restarts after it's sat for 10+ min.

Feel free to revive this thread if you don't wish to stay a new one, Ben.... I dont mind.