FE Build Driveability question

[joetrainer31]

Just installed a BBK 65mm TB. Went on a couple of QC drives after adjusting the idle to factory with spout connector out. Car runs fine until a WOT event. Afterwards, the idle will hang around 2k for a couple minutes. Then, I'll blip the throttle and car will return to normal idle behavior until next WOT. Is this asking for a base idle reset, a sledge hammer, or something else? Thoughts?

 

[General karthief]

Next time it hangs pull the throttle cable connection forward (closed) to tell if the throttle body is hanging or something else is happening.

 

[joetrainer31]

Next time it hangs pull the throttle cable connection forward (closed) to tell if the throttle body is hanging or something else is happening.

Now that you mention it the pedal felt a bit off. If it's hanging up, what to do. Never had that problem before.

Went ahead and got a Motorcraft TPS in case the BBK unit is trash. I've heard as much.

 

[WhiteCobra95]

You could try checking this in your driveway with the engine off. Just hold it at WOT for a few seconds, come off the pedal, and take a look under-hood to see if it has returned to the idle stop. If it's stuck, you could check out the throttle pedal situation under the dash. If it doesn't do it cold then warm it up, shut the engine off, and try again. If you can get it to happen in tests like this, disconnect the throttle cable and try again - that will tell you if it's the throttle body or something upstream like a bad cable or pedal.

You could also reinstall the original throttle and see if it does the same thing. If it's a cable or pedal issue, I would expect the same problem regardless of which throttle you're using, unless the BBK has a really weak return spring.

As a last resort, you could call BBK to see if this a common issue and what they recommend to check.

Good luck! I hope it's something simple, easy, and cheap to fix.

 

[Mustang5L5]

Went on a couple of QC drives after adjusting the idle to factory with spout connector out.

If you adjusted the idle stop screw, you should perform the base idle reset

 

[joetrainer31]

Next time it hangs pull the throttle cable connection forward (closed) to tell if the throttle body is hanging or something else is happening.

Would it achieve the same thing if, while driving, I use the top of my foot to try and pull the gas pedal towards me or are there too many variables between the accelerator pedal and the TB connection?

 

[General karthief]

Too much give in the cable, likely won't work unless the issue is the pedal.
JMO

 

[joetrainer31]

UPDATE: Turns out the throttle body was defective. The casting inside the body wasn't even and the buttlerfly would get stuck on the bad casting spot after passing it from WOT. Apparently, the cast wasn't bad enough to cause a permanent stick, but enough to hold it open for a bit. Getting a replacement TB. Thank you for all the help.

 

[WhiteCobra95]

That's kind of scary!

Great news that you found the root cause. Thanks for following up with the source of the problem. Hopefully the replacement part gets your car back to normal + a couple HP. =)

 

[joetrainer31]

That's kind of scary!

Great news that you found the root cause. Thanks for following up with the source of the problem. Hopefully the replacement part gets your car back to normal + a couple HP. =)

Agreed. Could've been really scary if it hung at a higher RPM. Anyhow, I don't expect any extra HP. I only replaced because the original TB spacer was all clogged up inside, and I thought, "replace it with a part useful in the future."

 

[Gs1987GT]

Good deal, glad you got it run to ground and at least they are sending you a new one and the sticking point was 2k and not wide open.

Hope with the new install you can put this issue to bed. Thanks also for the follow up post and resolution. Good stuff.

 

[rednotch]

UPDATE: Turns out the throttle body was defective. The casting inside the body wasn't even and the buttlerfly would get stuck on the bad casting spot after passing it from WOT. Apparently, the cast wasn't bad enough to cause a permanent stick, but enough to hold it open for a bit. Getting a replacement TB. Thank you for all the help.

That isn't the first time I've see that with bbk, seen more the a few even snap the throttle shaft. honestly hate the majority of there products.. used to stick to Old ford racing or Accufab for throttle bodies, these days thought the cheap billet flea bay china 75mm works well for sub $100 if but most don't have an intake large enough for one and they don't include an egr spacer.

 

[joetrainer31]

Good deal, glad you got it run to ground and at least they are sending you a new one and the sticking point was 2k and not wide open.

Hope with the new install you can put this issue to bed. Thanks also for the follow up post and resolution. Good stuff.

Thank you! And, great signature.

 

[Gs1987GT]

Agreed. Could've been really scary if it hung at a higher RPM. Anyhow, I don't expect any extra HP. I only replaced because the original TB spacer was all clogged up inside, and I thought, "replace it with a part useful in the future."

Awesome scripture passage in your signature also!

 

[joetrainer31]

Last update: swapped on another BBK 65mm TB w/a Motorcraft TPS. Everything runs completely fine. Thanks again, guys!

 

[7991LXnSHO]

Last update: swapped on another BBK 65mm TB w/a Motorcraft TPS. Everything runs completely fine. Thanks again, guys!

I am glad it’s going. The only problem I have heard about BBK (and some other aftermarket TB) is whistling when the IAC is open. Mine whistles an in tune F#, and I do not mind it with as loud as the car already is.
Are you getting a whistle at idle?

 

[joetrainer31]

Just checked. The replacement does not whistle, but the old one did.