Stalling from light after long highway driving w/cruise control

[Fix4Dirt]

I could be wrong but was under the impression that the TPS has double resistive elements such that if it is going bad, the two won't be in sync and will throw a code.

I'd start by checking fuel trims with a scan tool showing live data, and temperatures, and check fuel pressure, and clean the IAC valve. If it only does this after getting hot, it could take a while to nail down the problem. I'd also try it with the A/C off and check your pulleys since that is easy to do.

i dont doubt your expertise, but ive seen a TPS (on an ohv not sohc) that gave inconsistent readings and was slow to snap back and didnt throw a code. that was also a 95 though

 

[slick3d]

How could it not be fast enough? I suppose it could be intermittent contact but otherwise, electrons move near the speed of light.

Very true, I just meant if it was going bad, but then it shave throw a code. I hate it when it's an intermittent problem and it could be many things.

 

[slick3d]

i dont doubt your expertise, but ive seen a TPS (on an ohv not sohc) that gave inconsistent readings and was slow to snap back and didnt throw a code. that was also a 95 though

I will test it and see if it has any flat spots , with a live graph from a scanner

 

[Fix4Dirt]

Ok, thank you for the feedback. I will check my throttle body as well, maybe it's gotten dirty. I wonder if the TPS is getting confused after being on the highway for long period of time under cruise control then coming to a quick stop and then having to go from a stop sign, it's not responding fast enough? I'm not sure....

i wouldn't think that the TPS would be that "lazy" so to speak. if anything for me id suspect something heat related. if when youre on cruise if you step on it to pass does it do the same?

It would have to be a scan tool specifically capable of live data. The cheap ones only claiming OBD2 code reading won't work. Yes, the ELM327 based dongles that connect to your phone, especially using an app like Forscan, will work.

my regular use is the obelisk mx+ or whatever its called with the phone... if i doing something more involved or at home then for scan it is

Very true, I just meant if it was going bad, but then it shave throw a code. I hate it when it's an intermittent problem and it could be many things.

yeah. it usually takes a few minutes of an issue to set a CEL for example before id unplug IAC and it'd stay running (found out had a vac leak) but thats besides the point i could drive it IAC unplugged a few minutes before it'd set a code. but if you say it starts back up then it'd be to short to set a code


However, my gut thinks its kind of an opposite/same issue that i had with this one. every here and there when its hot, it would high idle horribly (ie. 3k in park, 1-1.2k in drive, and it'd feel like its driving itself...) or every so often it'd do the exact opposite and stall. since replacing the IAC and TPS pigtails (the wiring at the end) it'd never once come back after a few thousand miles

 

[slick3d]

It would have to be a scan tool specifically capable of live data. The cheap ones only claiming OBD2 code reading won't work. Yes, the ELM327 based dongles that connect to your phone, especially using an app like Forscan, will work.

Thank you

 

[Fix4Dirt]

I will test it and see if it has any flat spots , with a live graph from a scanner

can do with just a multi meter, since scanners are a bit slow to read these things imo

 

[Fix4Dirt]

2000streetrod on here has a thread on testing TPS iirc

 

[slick3d]

i wouldn't think that the TPS would be that "lazy" so to speak. if anything for me id suspect something heat related. if when youre on cruise if you step on it to pass does it do the same?

my regular use is the obelisk mx+ or whatever its called with the phone... if i doing something more involved or at home then for scan it is

yeah. it usually takes a few minutes of an issue to set a CEL for example before id unplug IAC and it'd stay running (found out had a vac leak) but thats besides the point i could drive it IAC unplugged a few minutes before it'd set a code. but if you say it starts back up then it'd be to short to set a code


However, my gut thinks its kind of an opposite/same issue that i had with this one. every here and there when its hot, it would high idle horribly (ie. 3k in park, 1-1.2k in drive, and it'd feel like its driving itself...) or every so often it'd do the exact opposite and stall. since replacing the IAC and TPS pigtails (the wiring at the end) it'd never once come back after a few thousand miles

2000streetrod on here has a thread on testing TPS iirc

When on cruise control and I need to step on it, I don't have any problems, quick to response.
I will check the thread on testing it, thank you for all the info.

 

[Fix4Dirt]

When on cruise control and I need to step on it, I don't have any problems, quick to response.
I will check the thread on testing it, thank you for all the info.

actually, if it doesnt do that on cruise, thats really odd. im not sure i know what to make of that... im not familiar enough with cruise to know

 

[Pete Deering]

Would a TPS that is going bad throw codes?

No, some times a bad TPS will cause true idle to increase. You can check the TPS with a multi meter.
Put it on resistance. Connect one lead too the return signal pin and the other lead to the ground pin.
Then open and close the throttle, and watch the meter. The resistance should go up and down smoothly. If the TPS is bad there will be a bad spot.
You also can back probe it and read voltage. The voltage should go up and down smoothly.
A bad coolant temperature sensor cause the to stall.
Scan for codes!
Disconnect the MAF sensor and if is any change.

 

[Turdle]

^^^^ this plus snap the throttle quickly, let the spring return it to idle with full force several times. The idle voltage should return to <1 v same value every time using key on engine off voltage check

 

[slick3d]

No, some times a bad TPS will cause true idle to increase. You can check the TPS with a multi meter.
Put it on resistance. Connect one lead too the return signal pin and the other lead to the ground pin.
Then open and close the throttle, and watch the meter. The resistance should go up and down smoothly. If the TPS is bad there will be a bad spot.
You also can back probe it and read voltage. The voltage should go up and down smoothly.
A bad coolant temperature sensor cause the to stall.
Scan for codes!
Disconnect the MAF sensor and if is any change.

Thank you for your help, I'm not getting any codes and it only happens getting off the highway after driving for a long time under cruise control, stopping at a stop sign and then trying to accelerate. No other symptoms other than once in a while, trying to accelerate on the highway and it's not responding unless I floor it.

 

[Squirrelmaster]

I'll throw out a suggestion based on a similar situation I had with my old '95 Explorer with the OHV 4.0L, which is check the functionality of the Idle Air Control Valve. My '95 would stumble just off idle when the engine was heat soaked from sitting in traffic or running on the highway, and I found it was that the IAC was dirty enough inside that it was slow to actuate. After a stop, when I would press the gas pedal the IAC would lag in closing and let unmetered air into the engine and cause to it to stumble and occasionally die. In my case, however, it would do that whenever the engine was hot, so even after a restart it would run sort of poorly. It still might be worth looking into.

 

[slick3d]

I'll throw out a suggestion based on a similar situation I had with my old '95 Explorer with the OHV 4.0L, which is check the functionality of the Idle Air Control Valve. My '95 would stumble just off idle when the engine was heat soaked from sitting in traffic or running on the highway, and I found it was that the IAC was dirty enough inside that it was slow to actuate. After a stop, when I would press the gas pedal the IAC would lag in closing and let unmetered air into the engine and cause to it to stumble and occasionally die. In my case, however, it would do that whenever the engine was hot, so even after a restart it would run sort of poorly. It still might be worth looking into.

Thank you for your suggestion, I will definitely check it out.