OOOOOps forgot to add a new Cal, cat. But the manaflow cat I took out was clear, and was only 2 years old. Anyway the 02 cost 109$ or so. Maybe the Cal cat takes out more nox?

 

Just 1 02 sensor.

 

Das cat

 

Hahaha... Das CAT, FORSUREGEN! lol.

 

Figured I'd revive this thread(after all, it IS about "troubleshooting", haha).........

1. Been having an odd occurrence; Seems to be only when RESTARTING motor after running around/operating temp.....

.....a. Idle seems to drop down to 500rpm when restarting after fully warm
.....b. Corrects itself fairly quickly

2. When hitting HIGH rpm(like 4000rpm - and above, HIGH)..... I'm getting a STRANGE sound, hard to describe.

.....a. NO vibration or hesitation, whatsoever
.....b. Sounds like a fairly loud hissing, like an intermittent air compressor being discharged, possibly along with some almost bearing sounding noise?
.....c. When Wheeling in Havasu and Angeles Crest, recently/since last rebuild; I notice when hitting hills and high rpm in 4LOW, as I head up the hill I hear a high pitched squeal, like a Work Horn Going OFF! Only higher pitched(It might do it without being in 4wd, I just don't get to that high of torque/rpm when on the street). Doesn't do it under ANY other conditions, period.

3. STILL, after 3 years, have the same odd miss... 2 years later, 2 motors later, around every part being replaced or swapped out, etc., etc......... STILL HAVE THE HICCUP AT IDLE.........

.....a. NOOOOOOOOO backfire or misfire(VERY RARELY when I first start in the morning and head down the steep hill to the main street... I'll let off the gas in 1st or 2nd and hear a pup-pupupupup-pup.........pup that I don't normally ever hear... But other than that, NO popping, etc., as mentioned. (I've pretty much given up on the gremlin, but my mileage still sucks in town, around 12mpg if I'm on it at all..... up to 23+MPG ON HIGHWAY IF I'M KIND TO HER! .... Might be totally unrelated to the miss... Just thought I'd throw out this in passing to just keep it in the background of my mind, to motivate me to ONE DAY FIND THIS BASTAGE! hahaha.

Take care,

Back to work

 

OK; Well, I'll post for my own sake, hahaha....

1. I have verified that the rig is NOT seeming to drop in idle when starting from Cold/warming up.

2. Thus, it is ONLY bogging down;
.....A. when fully warm
.....B. when RESTARTING after running around or even after warming it up in the driveway and then coming back to it and RESTARTING.
.....C. corrects its self after a few seconds

Going to try and have the FPRegulator rerouted to the Plenum without the VSV next time I restart warm... just to see if my issue might be HOT SOAK.

 

Boy I have the same problem, 500rpm at resart after warm up. Does not bog as I rev a bit to pull away. And resumes regular 750 idle quickly. i will pull the cool temp sensor at some time and test or just get a new one.

 

I'm going to test the CTS as well... But it checked out ok after 300K miles, just at this last rebuild. I HAD a Napa CTS in there... Removed it to put the OEM one back in after it tested fine on the bench/hot water-watching it descend in temp while measuring, etc........

Not so sure my problem isn't Hot Soak Related though, Teuf.... Guten Tagen, BTW!

I'm also going to rule out the Charcoal Can and the FPR-VSV, etc., etc. All easy tests that are FREE! I have that Napa CTS still, so I might test them both, for comparative values.... Then decide. Maybe the OEM one is just coincidentally going out. Then again, have no clue anything's even wrong with it until testing, ya know?

 

Seems I have a similar problem in my rig. It doesn't idle up on cold start, when it's been warmed up and shut down then turned back on while still warm it bogs down for a bit. Other than startup it idles perfect. I think I've narrowed it down to the AAV. I found a used one and it helped but the same problem is still there just not as bad. Before I had to keep my foot on the gas for about a minute or two while it warmed up now it's just when I fire it up it idles around 500 then creeps up to 1000 and once it's warm back down to 750. Unfortunately a new AAV is like $200 so I'm just gonna live with it for now, but you might want to test yours.

The FSM has an on engine test for the filiment, I can't remember what the resistance is supposed to be but I think it's around 30-50 ohms. This is what heats the bi-metal piece that closes the valve when the coolant running through the AAV is warm but not hot enough to close the valve. If you take the AAV off when cold you should be able to see through the hole. The way I tested mine was CAREFULLY took a torch to where the coolant runs through it to see if the valve closed. If it closes as it heats up it should be working, if not like mine was it should be replaced.

Hope this helps a little, i spent a long time trying to figure this out and it's still not quite up to my stantards, but it's better than before.

 

Thanks, B-Fake.... Appreciate the input.........

1. My IACV(AAV) is nearly Brand new, OEM(Don't remember paying near 200$... but I get 20% off... Seem to remember it being around 160$)

2. My rig idles up to 1100-1200rpm fine, any time it's cold, and I don't experience this hiccup UNTIL IT'S at full oper. temp.

3. Both hoses to the IACV are OEM/new... Nice soft rubber and sealed up well, and the Coolant Inlet on the back of the Timing Cover is nice and clean, which feeds the IACV. As is the other end(also all brand new Coolant Hoses, including the smaller lines...EXCEPT for the Heater Core... Gotta replace those )

Hey, my newer IACV might have taken a turn on me... never know..But I doubt it. It'd be down the line on things I test, but if it comes to that, of course I will....

Thanks again, B-Fake, very much appreciate you taking the time to chime in!(and very much appreciate the difficulty/level of FURY that can be caused by a pesky/difficult to diagnose gremlin... TRUST ME! hehe)

 

Today, I ran around quite a bit... Thought I'd try something out. So, when coming out of Del Amo Mall for a couple hours.... I bypassed the FPR-VSV..... DID NOT change or solve anything.

When arriving home, 10 miles later, I decided to turn off the motor, then restart it........ NO BOGGING DOWN! It only seems to do it when I've let it sit for a while...................

WTH? This seems REALLY familiar to me, even maybe within my library of 'personal vehicle drama/gremlin hunting'.

I can NOT stand for this nor take a 'for now' approach... My brain will rebel! hahaha.

So far, I think it's safe to say that EITHER the FPR is taking a dump on me and is somehow causing a symptom that doesn't really correlate with FPR Drama... Or it's SOMETHING ELSE! lol.

Next step will be CTS!

 

Happy to help, or at least try to. Lol. These idle gremlins can be a real pain. I wonder sometimes what the hell Toyota was thinking when they designed this EFI system. When it works it works great, but if there's even the tiniest thing wrong it's quite a chore to track it down. But hey this is Yotatech, if all of us can't figure it out, there is no solution, lol.

 

Just updating my troubleshooting stuff(I will edit as I go/as I remember things);

1. When cold, it idles up with it's new IACV as it's supposed to, to 1000-1100 or so(depending on ambient temp/coolant temp....it's nearly 100*F, so,...lol)... Idles down to 750(at least by what the tach says) and runs 'OK' thereafter(the "OK" left for another numbered description)...UNTIL I turn it off... When I return to the rig from the store, whatever, minutes later.... It idles down after a few seconds to 450-500rpm and sounds almost as if it'll stall/also as if it's running on 2 cyl's...strange "chu-chugga-chu-chugga", rather than "Chug-Chug-Chug-Chug"..... then with a lil feathering of the skinny.. it smooths out on it's own. If I don't feather the pedal at all... take a bit longer to get there.(I haven't just let it stumble like that, so it might not come out at all for all I know, to be honest, without feathering the pedal, ya know?)... That's the most recent and while not stalling or seemingly getting worse... IT'S TICKING ME OFF! lol... It does NOT do it, from what I can tell, if I turn the rig off and start it right back up..... ONLY after it's been sitting a short while... 10-20 minutes most often.

2. Depending on traffic, I'm getting between 12-24mpg, city/hwy... WTH? haha. This tank at 9 gallons down it gave 148 miles... 16.1... with SOME freeway, mostly City.... / Tank before that, NO freeway that I remember, 12.1mpg's. / Highway to Barstow, up the 15hwy hills, etc., from Palos Verdes, CA, ... 23.8mpg.... (Just starting to wonder if this newly 'hot soak' or 'vapor lock' or 'wonky sensor'/almost all of which are new.... that's causing my 'stumbling/idle down thing'...Also curious if it might be related to the bad mileage. as well, which I've had for a while(in town, only, on the bad mileage)

3. The 'running ''OK'' portion; Well, it's just a hard to describe, what feels like, "MISS"... But no misfire, no smoke, no backfire, no pinging, no NOTHING, and plenty of power..... Nonetheless, the miss is TERRIBLY annoying, while most get in it and say, "wow, runs better than mine", that means nothing to the owner of the miss, right? hahaa. Also curious if this is related, but at this point(For around 12K miles of chasing my tail, etc.)... I've just resigned to drive it and figure it out over time... But now I'm starting to worry that it might be too rich(which might have burnt out my last cat so fast....although it was a CATCO on a TERRIBLY done rebuild!)... Still seems like WHATEVER this stupid gremlin is... it's followed me to this point, 2 motors later from original.

4. Rig bogs down to 500 when AC is on.. I would like to solve this. Thinking it might be the replacement AC VSV I got(Broke off a port, so had to replace it)... Or the RPM dial in the dash behind the glove? Even though it idles down when the Clutch kicks in... it doesn't run ANYTHING LIKE when it's bogging down on fully warm restarts. Not sure, but DON'T THINK the two are related.. Can't see how.

Just to fill you in on stuff I've replaced/done over time......

NEW: 02/ TPS/ TTTSwitch/ IACV/All 5 injectors serviced/ Fuel filter around 12K miles/ EGR Modulator brand new OEM/ New Magnaflow Gold CAT/ COR fairly New/ Denso 70A Alternator 8K miles/ Duralast Gold fairly new-testing fine/ 12K Mile old Bosch Fuel Pump/ Almost new Radiator/New Water and Oil Pumps/ Orig. Fan Clutch... seems to work, NEVER overheats, EVER! Not even idling with the AC on for 20 minutes in 90*F weather/ New Steering Pump/ All new Denso OEM AC O-rings and Drier and it's pumping NICE AND COLD for over a year, 2 hot summers later/

* AFM swapped out, didn't seem to run differently/ EGR clean and seemingly working fine with it's new Modulator/ Replacement Throttle body I got with a spare intake I picked up from another 87 4Runner with lower miles than mine, wrecked/

/// New Valves, Eski Dual stage springs, viton seals, manganese bronze guides, 261 Engnbldr CAM wearing nicely, all new Adjusters and nuts(OEM), Nice wearing Rocker pads, Head worked over nicely, New .20 Over Pistons, Hastings USA rings, Sankea Bearings, Crank turned 10-10, Not using ANYYYYYY oil(still totally full at 3K miles)///

Things I'VE NOT swapped or replaced and some not tested;

* Haven't tested the Charcoal Canister

* Haven't made 100% sure that there's no kinks in the fuel lines(BUT, .... it runs like a raped ape once it's running, 90MPH even!)

* Haven't replaced the EGR/BVSV/CSI Time Switch/ Coolant Temp Sensor is my Original one... Pulled a new Napa unit and put my Original back in...can't remember why, probably just NUTS from chasing my tail so much! LOL

* Have had 3 ECU's in there, none have seemed to make a difference(all donors from purring rigs that didn't need em, let me have em + one that I bought for 50$ a time back when the dealer foreman mechanic suggested it lol.

* I HAVE NOT replaced the Distributor, Coil or Ignitor(Tested all 3, including air gap, shaft play, resistance, etc., 100 times)

* I have NOT, dug into the harness regarding the 'Y-Connections' realm that so many have issues with

* I have not replaced ANY fuel lines

******** IF you've chimed in on something, before... and you see I've not checked it/verified it? PLEASE remind me, even with a "Hey, dummy... I told yaz>>>> " ok? hahaha. I WILL check/test ANYTHING that's suggested, granting I have the tools/equip, promise. Just been crazy for me, honest.

I'll add more, but for now..... I'ma BEAT~!

 

Your first paragraph describes mine to the T, although I have no perceptible hesitation. I will test my CTS and or just put a new one in and report back.

 

Thanks , Teuf.... I appreciate it. Best wishes on your hunt ....

I know it's a lot to take in, sorry guys. It's just what it is/thought I'd try to leave LESS stones unturned before I dive in again with the help of some good peeps here on Yotatech!

I'm OBVIOUSLY missing something... Guess it's time to run through the suspects again(including EVAP and other Emissions section CRAP! lol)..Cuz, .... Just want 'THE' answer, more than anything now! I DON'T CARE HOW I get that answer! >>>>> 2+ years with that miss through 3 motors? AHHHHHHHH! (The stumbling thing is fairly new, but I DID have a similar gremlin before! It would get to 90*F, where sensors and such start to wake up...and start missing like crazy... That was the TPS or CTS... Replaced them both, but now have to go back and see if I didn't put the old CTS back in...To be honest...I can't remember!)

PS> Teuf? .... I guess it could very well be the CTS... The symptoms are a lil different, usually, I think.. But I'm REALLY thinking something more like 'evap' issues or the like are going on. Vapor lock or hot soak, SOMETHING odd! Have you ever pulled your Charcoal CAN and tested it? I've printed out the testing procedure, days ago... Gonna finally do it and report back.(It can be cleaned, to, from what the FSM says.. NOT SOAKED or taken apart or anything... Just "45# forced air, while plugging so and so port", etc., ya know? KSTI just reported on my build pertaining to this... He's a VeeZee owner.. but still... Canister works similar or the same in his, no? Mine has been HISSING like his on occasions... But I've seen no 'bubbling' or obvious compromises in the body of the Charcoal can.. so I'll have to just pull and test it, which is probably good maintenance/practice anyhow, bleh! lol.

 

Hey chef, what is the CTS ?, I probably know what it is but right now its not coming to me. On some other toyota truck and 4Runners I have owned I have replaced some sensors if they were original because ive found that even though there good, its seems like they get weak and don`t operate like they should after 20+ years of use. I usually replace the 02 sensor, the thermal time switch, the coolant temperature sensor, and TPS. Some might see this as a waste of money, but ive always had trucks that ran perfectly because of it.

 

Hey MYYOTA (Not sure you wanna share your name, so I'll leave it at that, not meaning to be impersonal lol).

I'm going to repost that long one on this page, just so people don't have to go back, which I know is pretty common, lol.

For now, in answer to your question/reiterating the rest;

1. The CTS is the Coolant Temp Sensor(next to the CSI time switch).. Sorry, I should have stated that.

2. I'm assuming that you're just giving me confirmation that my replacing the things I have has been a 'good maintenance practice', lol... But in case I misread that...

.....a. The TPS, Thermo Temp Time Switch, 02, Rotor/Cap/Plugs/Wires(LCE 8.5MM), Fuel Pump are all relatively new.

.....b. The Dizzy, Coil, Ignitor, FPRegulator, Damper, Evap Charcoal CAN are all original.

.....c. I'm now not even POSITIVE at all that this CTS is not NEW OEM. I have my receipts right here and will confirm/deny either way, asap! (I'll test it as well if necessary).

************************************************** ****************

Something that popped out at me, right off the bad, was on another thread for a Probe that a buddy of mine owns(it's a SLEEPER BEAST! lol)... He went through every sensor, etc., etc.... Had a VERY similar Gremlin of "Hot restarts wanting to stall"... Walked into his buddies Ford Shop and the guy IMMEDIATELY said, "It's the GAS CAP, that's TOTALLY vapor lock!".... Replaced the CAP and VOILA, solved! >>>>

1. My Gas Cap is ORIGINAL... But it DID pass the test at the Smog Shop(CA tests for that and the ENTIRE evap system....., not sure about other states... Figure they do as well). I'm going to at least order another CAP as preventative maintenance/to have on hand for long trips, just in case.. I mean, it could go bad at any time, and it's not worth it to have to fish around for one while I'm 200 Miles in the middle of nowhere, right? hahaha.

2. My charcoal canister also has a bit to do with dealing with pressure and sending fuel back to the tank, right? (gonna read up on it again).

3. My Fuel Pressure regulator... Not sure it could have anything to do with Vapor lock or the problems I'm experiencing. I'll eventually replace it.

4. I've heard EGR failure(also verfied to be good at Smog Check/and Modulator is new) can also cause 'Hot restart drama'... Gonna have to read up on that to verify that's even possible. That, and reading up on the FSM troubleshooting for my symptoms, as mentioned.

************************************************** ***************

I'll find it.... Between the book and the good peeps on here, as said,...."IT CAN'T HIDE FOREVER!" haha.

 

In my receipts I found these two.... I figure this one is the Water Temp Sensor next to the CSI time switch?>>>> 89422-12010 Replaced in June 2010

I'm guessing this is the Thermo Temp Time Switch(although the price seems too cheap as what I remember paying).. Thermo Temp Time Switch is on the top of the intake right on the Thermostat housing(maybe right behind it? Don't have it right in front of me)>>>> 89428-28030 Replaced July 2010

..... this is already giving me a migraine! hahaha. jk, jk! Maybe just a lil facial twitch at this point? lol.

 

The FSM in the "Poor Mileage" section says the obvious culprits... But also lists "Deceleration Fuel Cut System Faulty"..... Mine seems to work when Idle is above 1000RPM and brakes are applied... Doesn't work with the TPS disconnected(don't think it can, probably? lol).

 

Chef, I don`t care if you use me real name, its fine with me.

The thermal time switch is below the thermostat housing on the front of the engine.

With all the time you have put into your 4Runner you would think that it would be beyond perfect by now, but no matter what there always seems to be something that pops up that makes you pull your hair out trying to find it. But I know in the end you will get it figured out.