Part throttle limp mode and wrench light

[cloud9]

So my dealership is having issues with the hotline they say that the car must be returned to stock first and then reproduce the issue and of course the service manager says he can't reporduce it on the street. So apparently the manager is having to go to somebody higher on the food chain....anybody want to buy a slightly used racecar that can't do a 20 minute session without limp mode? I will throw in some tires

What specifically needs to be returned to stock? Just trying to figure out if there's a common thread between our cars since we seem to be the only ones experiencing it right now.

 

[Tucson 302]

What specifically needs to be returned to stock? Just trying to figure out if there's a common thread between our cars since we seem to be the only ones experiencing it right now.

According to the service manager ALL after market parts, but he told them to get bent that he knows what I've added to the car and those aren't part of the problem. Thinking back I never has this problem until I switched from the stock tires to NT01's and now slicks. It used to be the Service Advancetrac error but Shaun tuned out Advancetrac so now its the wrench. In fact after the first weekend this happened took it to Ford and had the code cleared then used street tires for the next event and had no issues. Don't have the 302S/R ABS module maybe that would help??? Just throwing stuff out of my frustrated brain!

 

[cloud9]

According to the service manager ALL after market parts, but he told them to get bent that he knows what I've added to the car and those aren't part of the problem. Thinking back I never has this problem until I switched from the stock tires to NT01's and now slicks. It used to be the Service Advancetrac error but Shaun tuned out Advancetrac so now its the wrench. In fact after the first weekend this happened took it to Ford and had the code cleared then used street tires for the next event and had no issues. Don't have the 302S/R ABS module maybe that would help??? Just throwing stuff out of my frustrated brain!

I doubt it has anything to do with tires since my issue pops up randomly......getting on the interstate, driving along at 30 mph on a city street, cruising on the interstate, running a warmup lap under caution and now at WOT on the track.

So you'd occasionally get "Service AdvanceTrac" while driving normally? I get that occasionally in my F-150 when towing but there's no wheel spin or erratic movement when it happens and will clear itself fairly quickly.......and no I don't track it or run R-comps on it I think they're just trying to wire in too many nannies and the sensors and ECU are occasionally getting overwhelmed.

 

[Tucson 302]

I doubt it has anything to do with tires since my issue pops up randomly......getting on the interstate, driving along at 30 mph on a city street, cruising on the interstate, running a warmup lap under caution and now at WOT on the track.

So you'd occasionally get "Service AdvanceTrac" while driving normally? I get that occasionally in my F-150 when towing but there's no wheel spin or erratic movement when it happens and will clear itself fairly quickly.......and no I don't track it or run R-comps on it I think they're just trying to wire in too many nannies and the sensors and ECU are occasionally getting overwhelmed.

I don't think tires are the culprit either but just seems like odd timing, I think the nanny theory is probably spot on wonder if there is a way to tune out limp mode...woo hoo my 500th post I'm now an addict!!!

 

[cloud9]

I don't think tires are the culprit either but just seems like odd timing, I think the nanny theory is probably spot on wonder if there is a way to tune out limp mode...woo hoo my 500th post I'm now an addict!!!

You don't necessarily want to tune out limp home or idle mode as it's a "fail safe" to keep your engine alive if you really do have an issue. In the case of the wrench light I think it's actually going into idle mode where you don't have any throttle response. The engine runs just enough to stay idling. The key is figuring out what's triggering it which is really hard to do when (in my case) it's so sporadic an infrequent and no obvious common theme.

 

[JScheier]

Are you running the curbing before this happens? I'm wondering if maybe the higher curbing or continued curbing is upsetting the knock sensors and that is putting it into limp even though no true misfire or lean condition is occurring? Can you recall anything interesting or different about the lap before the issue occurred?

One way to prove / disprove the knock sensor issue would be to unplug the knock sensors (making sure you are running good fuel) and hitting the track.

I went back to an early GrassRoots article (Mustang Mania) where Chris Cobetto was encountering issues which came down to the knock sensors. They unplugged them and the issue went away (but they ran race fuel to ensure no detonation).

Other than that, we were both on the same track at the same time in the same conditions. While I did get a CEL, I didn't get the wrench or limp mode. Of course, my car never seems to have the issues you have, other than cooling

 

[cloud9]

Are you running the curbing before this happens? I'm wondering if maybe the higher curbing or continued curbing is upsetting the knock sensors and that is putting it into limp even though no true misfire or lean condition is occurring? Can you recall anything interesting or different about the lap before the issue occurred?

One way to prove / disprove the knock sensor issue would be to unplug the knock sensors (making sure you are running good fuel) and hitting the track.

I went back to an early GrassRoots article (Mustang Mania) where Chris Cobetto was encountering issues which came down to the knock sensors. They unplugged them and the issue went away (but they ran race fuel to ensure no detonation).

Other than that, we were both on the same track at the same time in the same conditions. While I did get a CEL, I didn't get the wrench or limp mode. Of course, my car never seems to have the issues you have, other than cooling

Good info and a plausible explanation. Unfortunately in my case it's only happened this one time on track (other than on a warmup lap with no curbing) so it's mostly happening on the street. And no I'm not hitting the curbing on the city streets

 

[Tucson 302]

Good info and a plausible explanation. Unfortunately in my case it's only happened this one time on track (other than on a warmup lap with no curbing) so it's mostly happening on the street. And no I'm not hitting the curbing on the city streets

Me either it's alway in the straights at or above 7K RPM no curbing involved

 

[ArizonaBOSS]

Me either it's alway in the straights at or above 7K RPM no curbing involved

Derek have you asked the dealer to do a Misfire Monitor Neutral Profile Relearn while it's there? Takes them all of 5 mins if they already have the car. I dunno if you guys have done this yet but if not it's worth a shot.

I can do it with my IDS tool but it doesn't look like I'll be making it to INDE

 

[Tucson 302]

Derek have you asked the dealer to do a Misfire Monitor Neutral Profile Relearn while it's there? Takes them all of 5 mins if they already have the car. I dunno if you guys have done this yet but if not it's worth a shot.

I can do it with my IDS tool but it doesn't look like I'll be making it to INDE

Sorry to hear that Drew...I have not had them do this but will ask them too. I actually talked to Patrick at Watson today he says he's seen this before on several cars he suggested the Ford Racing throttle body may be the culprit (as have you) and to either go back to stock or have it dyno tuned with it on. I will try anything at this point!

Gary do you have an aftermarket TB?

 

[steveespo]

Some other things to check; dirty MAF, loose MAF wiring or broken pins. Throttle body connectors, intermittent faults here will cause the "wrench" too. Knock sensor problems cause CEL not wrench because they are fatal errors that can damage the cats. It is very difficult to pin down these problems, a good diagnostic mechanic is worth his weight in gold.
Steve

 

[Tucson 302]

Well after a week at the dealer they gave up. So I will start with the TB this weekend and put it on the Dyno and see what it does. If that doesn't work I'm giving this car to my wife for a DD and looking for something else to track

 

[Tucson 302]

Spoke to Shaun at AED about going back to stock TB and my tune he too beleives it's the TB causing the issue and is a known issue with the FRPP/Accufab TB

 

[ArizonaBOSS]

Spoke to Shaun at AED about going back to stock TB and my tune he too beleives it's the TB causing the issue and is a known issue with the FRPP/Accufab TB

Chris had issues with his Accufab TB. Works fine on stock TB. Still stock on mine.

 

[Tucson 302]

Chris had issues with his Accufab TB. Works fine on stock TB. Still stock on mine.

Yeah Shaun stated that the tune wouldn't need to be updated when I put the stock TB back in, too bad tho the FRPP TB was so nice and shiny

 

[ArizonaBOSS]

Yeah Shaun stated that the tune wouldn't need to be updated when I put the stock TB back in, too bad tho the FRPP TB was so nice and shiny

We can wrap your stock one in aluminum foil if it will make you feel better

 

[Tucson 302]

Well put it on the dyno today with the stock TB and did two pulls. No limp/idle mode it did great 424 HP

 

[ArizonaBOSS]

424 holy crap...NICE

 

[VoodooBoss]

Well put it on the dyno today with the stock TB and did two pulls. No limp/idle mode it did great 424 HP

Nice. Do you have headers and a tune?

 

[cloud9]

I have the stock TB so no common thread there. Made 437 with stock TB and LTs and off road mid pipe.