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Part throttle limp mode and wrench light

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cloud9 said:
I have the stock TB so no common thread there. Made 437 with stock TB and LTs and off road mid pipe.
And you'd probably be over 450 with a CAI and tune and drop another 0.01 from your lap times. ;D
 

Tucson 302

2013 Black LS #439
cloud9 said:
There's most of the power gain ;)

Yeah and I'm pretty sure it would have made more it was still going up at 7200 but that's all the higher they would let it go. I told them to take it to 7500 but the dude was ascared ;)
 

Tucson 302

2013 Black LS #439
ArizonaBOSS said:
hahaha what shop did you go to?

PSI Performance here in Tucson. From the looks of the cars they had in the shop they pretty much focus on small bore engines. I didn't know they were even here until I called the other so called "race shop" in town looking for a dyno
 

Tucson 302

2013 Black LS #439
New throttle body = new day!!!!! Well old stock one, but you get the idea

Spent the last two days at Inde here in AZ total of 10 sessions and zero limp mode! What an amazing feeling it is to actually do a full session without issues

Drove Hotlaps (time trials) with ArizonaBoss driving his buddies Vette.....humbling, but I did finish second on Saturday in my class and first today so woo hoo :)
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
441
Southeast
Tucson302:

Glad to learn you sorted out the limp mode issues on your car. I too have the FRPP TB and your right, it does look good under the hood. If I have to reinstall the stock TB, I figure the FR TB will make a nice ornament for the Christmas tree.

Nice job on the podium finishes! You're running with some pretty fast company.

Hi Pro
 

Tucson 302

2013 Black LS #439
NFSBOSS said:
So what's the issue with the Accufab/FR TB? Mine runs well with it. Is it only when a tune is applied? Anyone have any documented info and links on this?

Rick check with Shaun at AED or Patrick at Watson they both told me that they knew of the issue, that its good in some cars and not so much in others. I'm pretty sure I remember this happening prior to the tune just not every time I got on the gas
 
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cloud9 said:
No it happens randomly. Generally on the street or highway, rarely on the track.

By randomly u mean when there is a problem or randomly u mean by anytime even when there are no issues in the car ? :/
 
eng90 said:
By randomly u mean when there is a problem or randomly u mean by anytime even when there are no issues in the car ? :/
There is no known cause or correction at this point. It happens randomly without any particular issue with the car. It is VERY intermittent meaning you could go months, weeks, days or hours between occurrences. The only thing I find somewhat consistent is it seems to happen when holding steady at part throttle, but not always. We have datalogged without any luck, and it doesn't leave a DTC code after you restart the car. I do get a P0611 code on my OBDII reader if I check before turning it off, but Ford says that's not a valid Mustang code. It's for diesel engines and related to the fuel injector control module.
 
898
544
Cloud9,

With regard to limp mode, wrench light, and no codes, did you ever find a solution for this issue? This has happened a few times in my Boss with the most recent this week. I have a stock TB, so I am ruling that out as a possible source.

Thanks
 
2012-Boss said:
Cloud9,

With regard to limp mode, wrench light, and no codes, did you ever find a solution for this issue? This has happened a few times in my Boss with the most recent this week. I have a stock TB, so I am ruling that out as a possible source.

Thanks
Unfortunately, no. The car actually goes into idle mode, not limp mode (at least in my case). Idle mode means it doesn't respond at all to throttle input and just maintains enough fuel to idle and not kill the engine. The more I researched it, this is the exact behavior designed into electronic throttle control as required by the government for safety reasons. It's a result of the "runaway car" syndrome often reported by drivers in the past several years. I'm not sure whether any of these instances were ever proved to be not operator induced, but nonetheless the manufacturer is required to program the vehicle with this fail safe feature to prevent it from happening. In my opinion, that's what is happening on the Boss in this isntance. I don't know if it's a programming issue in the PCM or if it's due to faulty sensors or shorts in the wiring to the throttle body. If I were you I'd push for a TB warranty replacement to see if that solves the problem.
 
898
544
Ok, thanks for the help. I am probably switching to a Cobra Jet intake and throttle body this spring. With that and the increased difficulty I am having with my dealer, I am not going to worry about replacing the stock TB right now.

Steve
 

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