Hesitation/Stumble on kickdown @ WOT
05-13-17, 07:25 PM
#1
Dysfunctional Veteran
Thread Starter
Hesitation/Stumble on kickdown @ WOT
Not sure whats up with the Lexus, but its not acting right. Lately its been "stumbling" which i attributed to the quirky drive-by-wire programming initially, until today.
today, i went to pass someone doing 55 in a 70 on a back country (2-lane) rural highway. I had to put the gas all the way down because a car popped over the hill in the lane i was using to pass, about a mile ahead of me. I punched it, trans shifted down (rather lazily, its not a performance car after all) to 3rd, and all of a sudden it felt like the car was gonna jolt me out of it. A violent shudder as i hit 100%throttle that started right after the downshift. It felt like the engine was starving for fuel. It had a half tank. It wasnt a slip of the trans, it was a hesitation of some sort, either electrical (ignition), lack of air (not likely) or lack of fuel.
im not sure which. There were no lights on the dash that came on, and no codes stored. Thoughts?
02 ES300, 156k miles, dealer maintained since new.
today, i went to pass someone doing 55 in a 70 on a back country (2-lane) rural highway. I had to put the gas all the way down because a car popped over the hill in the lane i was using to pass, about a mile ahead of me. I punched it, trans shifted down (rather lazily, its not a performance car after all) to 3rd, and all of a sudden it felt like the car was gonna jolt me out of it. A violent shudder as i hit 100%throttle that started right after the downshift. It felt like the engine was starving for fuel. It had a half tank. It wasnt a slip of the trans, it was a hesitation of some sort, either electrical (ignition), lack of air (not likely) or lack of fuel.
im not sure which. There were no lights on the dash that came on, and no codes stored. Thoughts?
02 ES300, 156k miles, dealer maintained since new.
05-13-17, 07:40 PM
#2
I know you know your stuff so I feel dumb suggesting it, but possibly plugs? It's a service a lot of people skip over, but at 156k they're way past due with a 120k interval. I felt a huge difference when I changed mine at 103k, but it never completely missed like you are describing
05-13-17, 10:42 PM
#3
Very basic, but how high did it rev? Were you watching?
I recently had a similar experience. On an uphill a car pulled in front of me and I punched it to the floor and swerved (2002, same car as yours) and it revved so fast after downshifting I hit the redline and ECM cut-off so fast I was stunned (since the car is rarely over 3200rpm in normal use). In the right conditions, a downshift and transition into the VVTi sweet zone can take you to that limit shockingly fast.
OTOH, on a second reading, I see you are saying this is a chronic stumbling issue, then possibly expect a coil fault code soon. Sounds like you have a marginal coil that is only intermittently failing under heat/stress. TX heat, the age and mileage are about right for that. I had a slowly failing coil in a Land Cruiser that did this. I have had one coil fail in the 2002 ES in 273k miles and it stumbled a few times w/no code before it threw one. If you cut a bad coil open, you can easily see how heat or stress exacerbate it, and it can act normal at 98% of driving conditions.
The factory plugs, if still in it, should actually still be good barring a manufacturing defect. If still original, they are overdue, but these are incredible plugs and odds on, are still working OK. Sounds like you would know this.
Aside, where did you earn your Purple Heart?
I recently had a similar experience. On an uphill a car pulled in front of me and I punched it to the floor and swerved (2002, same car as yours) and it revved so fast after downshifting I hit the redline and ECM cut-off so fast I was stunned (since the car is rarely over 3200rpm in normal use). In the right conditions, a downshift and transition into the VVTi sweet zone can take you to that limit shockingly fast.
OTOH, on a second reading, I see you are saying this is a chronic stumbling issue, then possibly expect a coil fault code soon. Sounds like you have a marginal coil that is only intermittently failing under heat/stress. TX heat, the age and mileage are about right for that. I had a slowly failing coil in a Land Cruiser that did this. I have had one coil fail in the 2002 ES in 273k miles and it stumbled a few times w/no code before it threw one. If you cut a bad coil open, you can easily see how heat or stress exacerbate it, and it can act normal at 98% of driving conditions.
The factory plugs, if still in it, should actually still be good barring a manufacturing defect. If still original, they are overdue, but these are incredible plugs and odds on, are still working OK. Sounds like you would know this.
Aside, where did you earn your Purple Heart?
Last edited by Oro; 05-13-17 at 10:47 PM.
05-14-17, 02:03 AM
#4
Dysfunctional Veteran
Thread Starter
Very basic, but how high did it rev? Were you watching?
I recently had a similar experience. On an uphill a car pulled in front of me and I punched it to the floor and swerved (2002, same car as yours) and it revved so fast after downshifting I hit the redline and ECM cut-off so fast I was stunned (since the car is rarely over 3200rpm in normal use). In the right conditions, a downshift and transition into the VVTi sweet zone can take you to that limit shockingly fast.
OTOH, on a second reading, I see you are saying this is a chronic stumbling issue, then possibly expect a coil fault code soon. Sounds like you have a marginal coil that is only intermittently failing under heat/stress. TX heat, the age and mileage are about right for that. I had a slowly failing coil in a Land Cruiser that did this. I have had one coil fail in the 2002 ES in 273k miles and it stumbled a few times w/no code before it threw one. If you cut a bad coil open, you can easily see how heat or stress exacerbate it, and it can act normal at 98% of driving conditions.
The factory plugs, if still in it, should actually still be good barring a manufacturing defect. If still original, they are overdue, but these are incredible plugs and odds on, are still working OK. Sounds like you would know this.
Aside, where did you earn your Purple Heart?
I recently had a similar experience. On an uphill a car pulled in front of me and I punched it to the floor and swerved (2002, same car as yours) and it revved so fast after downshifting I hit the redline and ECM cut-off so fast I was stunned (since the car is rarely over 3200rpm in normal use). In the right conditions, a downshift and transition into the VVTi sweet zone can take you to that limit shockingly fast.
OTOH, on a second reading, I see you are saying this is a chronic stumbling issue, then possibly expect a coil fault code soon. Sounds like you have a marginal coil that is only intermittently failing under heat/stress. TX heat, the age and mileage are about right for that. I had a slowly failing coil in a Land Cruiser that did this. I have had one coil fail in the 2002 ES in 273k miles and it stumbled a few times w/no code before it threw one. If you cut a bad coil open, you can easily see how heat or stress exacerbate it, and it can act normal at 98% of driving conditions.
The factory plugs, if still in it, should actually still be good barring a manufacturing defect. If still original, they are overdue, but these are incredible plugs and odds on, are still working OK. Sounds like you would know this.
Aside, where did you earn your Purple Heart?
PH Was earned in an IED strike in Afghanistan.
I know you know your stuff so I feel dumb suggesting it, but possibly plugs? It's a service a lot of people skip over, but at 156k they're way past due with a 120k interval. I felt a huge difference when I changed mine at 103k, but it never completely missed like you are describing
Last edited by ArmyofOne; 05-14-17 at 02:09 AM.
05-16-17, 05:36 PM
#5
Driver School Candidate
I have a 2003 ES with almost 96k miles. I've had a similar experience. The drive-by-wire transmission has a mind of its own. It's almost like the car gets mad at you for driving it aggressively. I don't think anything it wrong - the transmission just has "senior moments" every now and then.
05-16-17, 09:38 PM
#6
I know some of the gen5/6/7 Camry guys use something like Weapon-R's iThrottle (throttle controller) to get rid of the issues with the DBW systems. Would this be something you would be willing to try?
From what I read they get slightly better fuel economy, too, in addition to the new, excellent throttle response.
From what I read they get slightly better fuel economy, too, in addition to the new, excellent throttle response.
05-21-17, 03:28 PM
#7
Dysfunctional Veteran
Thread Starter
I know some of the gen5/6/7 Camry guys use something like Weapon-R's iThrottle (throttle controller) to get rid of the issues with the DBW systems. Would this be something you would be willing to try?
From what I read they get slightly better fuel economy, too, in addition to the new, excellent throttle response.
From what I read they get slightly better fuel economy, too, in addition to the new, excellent throttle response.
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06-03-17, 07:22 PM
#8
Dysfunctional Veteran
Thread Starter
So I pinned this down today. I thought I would report back.
Today the car stalled on me. So I had enough. I popped the hood and there was a vacuum line that had come disconnected due to a broken fitting. So I bought some vacuum hose and some t-fittings and replaced them. All seems to be well now. Also seafoamed the car. Next week I will change the oil, not that any of that is related. But if this returns in any way, I will pop my head back in here.
Today the car stalled on me. So I had enough. I popped the hood and there was a vacuum line that had come disconnected due to a broken fitting. So I bought some vacuum hose and some t-fittings and replaced them. All seems to be well now. Also seafoamed the car. Next week I will change the oil, not that any of that is related. But if this returns in any way, I will pop my head back in here.
06-04-17, 11:47 AM
#10
Lexus Champion
06-04-17, 03:19 PM
#11
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