I had this same symptom years ago on my 98 Chevy Silverado. High idle all of the time. Back then I didn't have a scanner so I threw some parts at it. I think I changed either the IAC or TPS. That didn't fix anything. I went on one of the online forums and someone told me it was probably my thermostat sticking open and that the engine was not getting up to normal operating temperature. He was right. I put a thermostat in it and the problem was fixed.
Thank you so much! Really appreciate how you narrate your logic-tracks, especially the dead-ends and "nope, not that"... '96 3.4L Taco w/340k has similar symptoms, but maybe not the same culprit - this is getting me a whole lot closer!
A faulty ECT causes a long crank or no start. Luckily, google is our friend. Checked data and the ECT temp never moved past 50 degrees even though the customer brought it in running. This is also great info since I haven’t seen this on a Toyota yet. Very small shop and mostly newer cars, 2006 and up. Thanks!!!! 😊👌🏽
Same here but I was also leaning towards the iac. Same thing happened to my wife's 4runner. Cleaned the TB and it helped, changed the iac and problem solved. On a side note, the temp was normal.
"Spoiler alert" Wow! I totally thought it was going to be related to IAC or EVAP Purge solenoid stock open... looking at some Loop state (Open / close) at the beginning would help a lot just like the temp PID did. Thank you Ivan!
As you explained, Toyotas like a warm engine before reducing the gas intake. A cold engine is a start up and is equivalent to having the choke out on the old timer wagons of aother era. That said, when the choke was returned before warm up, the engine would splutter and die. So the computer knows a thing or two.
New sub here! I recently bought a 97 4runner Ltd identical color and everything to the one in this vid too and I love how thorough u are with ur explanation. Thx for the great content!
Senor ivan muy sweet . Looks like that snap on versus will pay for it self fairly quickly.Gave up on my car took to Subaru only shop . They're honest and fair. Wrenchrite in branford, ct.2006 sti with too many issues po448, 447, pcm issues,boost issues and clutch replacement with Exedy stage1 kit.Ivan much thanks for all your videos
One of my 2000 runners runs at 4000 rpm cold start its driving me mad Even ran fine yesterday scan data looks good on mine other then rpm thinking it's the Throttle position sensor went bad
Another well built vehicle right there. Imagine going 235k without doing a timing chain! 🤣 Never thought I'd see the day I'd be calling '96, "the good ol' days". I'm still on the ORIGINAL fuel pump on my 260k mile '86 Grand Marquis. 😎 She's just now starting to get noisy enough to hear it outside the vehicle without crouching down by the rear wheel well. I've seen quite a few cars with TPS percentages over 10% that ran just fine. Maybe a dirty throttle body. That used to raise a red flag for me when I first started diag'ing OBD-II stuff, but not anymore. Pretty nice run for a t-stat there!
Mine is doing the same thing. And after doing some research and confirming with a tech friend, I went and bought a Toyota OEM thermostat. based on this video, it seems to be the ticket. I'll be replacing it soon.
I cleaned my idle air control valve and now have a 1500 idle in park and neutral. Before it was around 600 and shutting off. That IAC sensor sends data to the ECU, right? I'm thinking I just need to drive the car for awhile till the sensor resets the data and brings the idle back down? Does that make sense?
A laser thermometer is a good way to verify the accuracy of the temperature sensor. Just point it at the thermostat housing and compare to the scanner reading.
great diag Ivan. this vehicle has a mech fan, even though it has a clutch it still turns all the time and pulls some air through the rad. that's probably why it never got to operating temp even sitting in the shop. properly functioning t-stat is even more important in that case.
The tps percentage could throw you off but I usually rely on the actual tps voltage for those era Toyota. Wish I could see the IAC percentage at hot idle. Thanks again for your vid and time Ivan.👍🏾
Love your videos Ivan. When you unplugged the ECT and the scan data temp dropped to it's min I was yelling at the screen to jump the two terminals harness side to make it go to the max temp and see if the idle drops.
@@PineHollowAutoDiagnostics I had an '86 Olds Cutlass Ciera. Wintertime, driving to work. Heater wasn't adequate, transmission wouldn't shift into lockup on the highway. I put a piece of cardboard in front of the radiator and continued to drive to work. Warmed up, heater worked, shifted into 4th. Next day I replaced the thermostat. Bingo. It had been stuck open.
Yeah Ivan there is another sensor regarding engine temp. Looking at my Toyota manual there’s a Water Temperature Sender in the harness diagram. I wonder if that was what you were talking about when you unplugged the ect sensor... I’m kinda curious about it now... thx for your time
The scan data changed the direction of the part to be changed. Great example of how important it is to have a scanner and be able to understand what is being displayed.
Had the same(ish) issue on a 02 Echo. IAC stayed at 67% and idled at 2300rmp. Temp sensor was at 190, AC off, PS pressure sensor unplugged and no change. Commanded IAC to 35%, all was good. Leave bidirectional controls, no data PIDs changed except for RPM and IAC, back to 2300 and 67%... head scratching, coworker asking, computer digging, RU-vid watching... finally went with "forums people always say 'disconnect the battery and hold the ends together for 5 min, fixes everything.' I'm out of ideas, so..." Fixed it.
I had similar issues with my 1997 T100 3.4L engine, 243K miles. I chased this high idle issue through a number of possible solutions and ended up with the engine coolant temp (ECT) sensor, located top of the block, forward, just under the fuel system tubes that feed the fuel injection rails. Here's a how to ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kyn94-CU1VQ.html . The ECT is connected to the computer and is a different thing from the temp sensor that gives data to the meter on the dash. What was happening is the ECT was telling the computer that the engine was not warmed up yet so the computer was racing the engine to bring the temp up. I could go across town without ever touching the gas pedal. Replacing the ECT sensor cost me about $36 which included the new ECT and a 19MM 1/2"drive DEEP socket to drive the ECT. It took me about 45 minutes to get in, replace and get out... and I'm not a "car guy".
You think a leaking valve cover issue could cause the high idle issues? Don't think it's my IAC or throttle body, both cleaned and reassembled, no diff at all.. I know I have an oil leak on the back of the pass valve cover.. Been waitin to do the valve gaskets when I do timing.. When I start it it hovers around 1800 till it warms up, but still won't go under 1200 or so.. 95 sr5 T100.. Great vid..
Those toyotas like to idle high until the coolant temp is above 165ish.. I bet something is up with the tstat. I didnt finish the video i wrote this as soon as i saw your coolant temp pid going down from 150 to 140. Pinch the upper radiator hose off.
Point a infrared temp sensor at the thermostat housing or where the temp sensor is located quick way to verify scan temp data usually within 10 degrees of each other
Everybody else goes straight to cleaning the throttle body then adjusting the iac by clocking it down.. but the temp is a direct relation to the idle as well as the evap and bunna crap also…
Used them all the time in the military - just a bunch of resistors that you "align" for a resistance value you want to use. The R's are in multiples of 10, thus a "Decade Box."
Questions such as.. in an automotive setting, what sensors can we use them on, which ones we can't, what ohm range should we use, what is the computer looking for, where would be possible to hurt the computer with them etc.
@@johnc4352 if I can be of some help..... well the resistor I use is from the aeswave test kit that has banana jacks to it and I first hook to my multimeter and set the ohm resistance to where i want and lock in place. U can mimick sensors using the decade box or the variable resistor that I use. Sensor like coolant temp sensor. CODY has a video where he used the resistor to mimick the fuel level sender to make the fuel guage go up and down to verify the cluster works and indeed confirm that he had a bad fuel level sensor. On a mercedes I had an ambient temp sensor low circuit code and I used my resistor to see a change on the scan tool. The sensor was ripped off from a bumper damage and it was just wires hanging so to make sure I was on the right circuit I hooked the resistor in place of the missing sensor to see if I can make the computer react and indeed it did. I set it low to like 30-50 ohms to be on the safe side and then if I want to see a little more change I turn the knob a little. Various things u can use it on so u can be the computer and see a change. Very powerful diagnostic arsenal in ur box. Hope this helps. Hope others can jive in as well
Those idle air control valves like to seize up if someone cleans the throttle body and lets all the cleaner go into the hole that leads to the IAC. to unstick them you have to pretty much flood the IAC port over and over again with throttle body cleaner while it’s running. I find that it’s best to just wipe these ones out. I’m only a few minutes so I have to wait and see what you find.
It's still idling way too high for a thermostat you need some kind of adjustment pull out on the where the cables hook up to pull that out and see if it slows it down more
I’m having this issue but I just replaced my thermostat about a 2 weeks ago. It wasn’t until the last couple of days where I’m having idling issues. However when I come to a complete stop at a intersection that’s when it seems to happen the most.
Bad thermostats can really mess with the engine computer. At times I have seen where the computer will not run the emission readiness monitors so the vehicle can pass inspection. If the temperature does not get to 180F or so, it will not run the monitors at all.
Ivan can't hear you in the video.Maybe fix the coolant temp prior to playing with idle? Should not take that long to warm up.does it have separate sensing signals? Can you check the input at the ECU? I would definitely clean that linkage and throttle body. Good video though Ivan just need some rain water LOL ❤️
I have removed the thermostat thinking that did not need it since is in the 70 all the time And caboon the same problem popup high idle So I went in and drop one back in it ty
Hey!!! I have this exact problem, RPM is about 1050, and when I change from P to R, R to D, it kicks very hard, I guess it's because the high rpm. I don't have thermostat on it.
@@PineHollowAutoDiagnostics previous owner did it… I’m outside the US so kind of tricky find good quality parts. Anyways I was going nuts trying to find why my rpm’s were that damn high. This could be the issue, right? And also the annoying and strong kick from the transmission when I shift from R to D
I believe the tps voltage was around 11 give or take, this said the computer was likely driving up RPM's to warm up the engine, thinking it was a cold start!
@@glenjohnson9660 Yeah after I saw the whole video that was clear but I have fixed similar problems on different cars by just having it draw brake cleaner or IPA through the idle valve depending on if its a plastic or a metal intake.
@@PineHollowAutoDiagnostics Almost Ivan. I have a hard pedal at the top with engine off. Engine on I have brake but long travel?? I had the wrong right rear caliber lh on rh. It helped but now the long travel. bottle bled all the wheels. I clamped all brake lines. Had firm pedal engine off and on! When I removed one had soft pedal and travel
Hey Ivan! instead of a decade box, could you ground ect like a bypass test with testlight? Would that possibly trick it into running hotter. Please advise :D
Wow I never thought that could cause a high idle I gatta do that to ymtoyota cuz ive had a 20000 rpm every time I start up my car then it lowers to 1500 still too high but I also have a big racing radiator