P1506 & Accufab Throttle Body

mlschultz

mlschultz

Boost King
Here's a new one for the forum, for those that have a Accufab ellipse throttle body. After the last tuning session before the SSHS13 shootout, The Mark somehow developed a P1506 code, that has it stalling at the most inopportune times, and throwing the code. The IAC was replaced, and it appears the reason is a gap around the blade is letting too much air go by when closed.

Aric is working on it now, and hopefully he will come up with a solution. If the TB has to be replaced, I told him to see about using the oval version instead. This TB has been on the car for years now, and why this has come about now is puzzling. Something like this should of come about immediately upon start up, if it is a faulty blade to body issue.

I was considering running the car at the NMRA/NMCA All Star Nationals at Atlanta Dragway next Saturday, since the car ran so well at SSHS13, but I am not sure if there is enough time to get it done. We will see how it goes... :)





 
Roadboss

Roadboss

On Work Release
1506 is a problem with the idle on the car, and it can be caused by several things, including a vacuum leak, dirty IAC, or bad TPS. Remember that the computor needs to go thru several drive cycles to relearn some of the parameters. I doubt that it is the TB at this point.
 
mlschultz

mlschultz

Boost King
Roadboss said:
1506 is a problem with the idle on the car, and it can be caused by several things, including a vacuum leak, dirty IAC, or bad TPS. Remember that the computor needs to go thru several drive cycles to relearn some of the parameters. I doubt that it is the TB at this point.
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What I posted is a known problem with Accufab TB's, Charlie.

Aric's shop is a Accufab dealer, and he is checking everything out before trying a new TB. I hope your right, and it is a vacuum leak, or something like that. I hate the thought of buying a new TB.
 
B

billcu

Head Moderator
Back in the carburetor days, if the TB plate was not closing all the way, we would carefully loosen the bolts on the plates just a little bit, let it close, then tighten them back up. You had to be careful not to loosen the bolts too much or they break off, because they are kind of crimped at the end of the bolt.
 
mlschultz

mlschultz

Boost King
Aric has been data logging The Mark, and doing whatever to the tune to see if he can fix without replacing the throttle body. Hope to hear something today on which direction he advises I take.

On another note... While The Mark was on the lift, Aric noticed the MT ET Streets are showing cords inboard, so the tires have been ordered from Summit, and a appointment will be made today to mount, balance, and 4 wheel align the car.

They are trying to get everything done for the NMRA race this Saturday, in typical fashion I might add... lol :)
 
Roadboss

Roadboss

On Work Release
Hope you do well this week end Mike. With what you have got invested in your ride you should turn that TB into a desk piece and mount up a new one.
 
9

97MarkJA

New member
mlschultz said:
Aric has been data logging The Mark, and doing whatever to the tune to see if he can fix without replacing the throttle body. Hope to hear something today on which direction he advises I take.

On another note... While The Mark was on the lift, Aric noticed the MT ET Streets are showing cords inboard, so the tires have been ordered from Summit, and a appointment will be made today to mount, balance, and 4 wheel align the car.

They are trying to get everything done for the NMRA race this Saturday, in typical fashion I might add... lol :)
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Make sure you get a couple of good burn outs on those new tires, the mold release tends to make them a little slick the first time out.
 
mlschultz

mlschultz

Boost King
Talked to Steve yesterday afternoon, and Aric tried a couple different TB's, and got the same result. :frown:

Therefore, Houston... we have a problem...

Process of elimination:

IAC - pass
tune - pass
Smoke test - pass
Throttle body - pass

As the story goes, there is now a mysterious vacuum leak (as Charlie predicted :thumbsup: ) The computer is doing it's job by working hard to wrangle the idle by pulling timing, adjusting values, etc., that basically turn off the IAC since it is pulling in all this unmetered air.

Aric suggests pulling the upper intake, and go from there. :mad-tilt:

I have not seen a quote yet, but I am getting a little pissed about this.

My opinion, there should not be anything coming loose, or not sealed properly under the intake. If there is, I can only look to the person that built the engine to explain why this **** is coming apart.
 
racecougar

racecougar

New member
97MarkJA said:
I have the same TB and haven't had any issues with it...... Yet
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No issues with the oval one here either.


mlschultz said:
Talked to Steve yesterday afternoon, and Aric tried a couple different TB's, and got the same result. :frown:

Therefore, Houston... we have a problem...

Process of elimination:

IAC - pass
tune - pass
Smoke test - pass
Throttle body - pass

As the story goes, there is now a mysterious vacuum leak (as Charlie predicted :thumbsup: ) The computer is doing it's job by working hard to wrangle the idle by pulling timing, adjusting values, etc., that basically turn off the IAC since it is pulling in all this unmetered air.

Aric suggests pulling the upper intake, and go from there. :mad-tilt:

I have not seen a quote yet, but I am getting a little pissed about this.

My opinion, there should not be anything coming loose, or not sealed properly under the intake. If there is, I can only look to the person that built the engine to explain why this **** is coming apart.
Click to expand...
Bummer. I'd question how it would pass a smoke test if it's pulling in enough air to trip a P1506.
 
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mlschultz

mlschultz

Boost King
SCTBIRD1173 said:
Glad you got it fixed Mike, hope the event went well!
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Thanks, Bryan! The event went great! The Mark clicked off low 7.8's @ 90-91 mph 1/8 mile passes consistently, even with IAT's in the 110's, which is very good for my car considering it was 80* Saturday. Track prep was great too. I was in on the gambler bracket, and racing against dedicated bracket race cars. lol After I lost 40 bucks red lighting, I called it a day... :embarrassed:

The topper of the day though, while I was parked in the car show and relaxing in my chair between bracket racing rounds, the editor from Muscle Mustangs & Fast Fords came up to me and asked if he could do a MM&FF feature article on The Mark. So the rest of the day was very cool having their photographer taking action & static photo's of the car. :thumbsup:




 
SCTBIRD1173

SCTBIRD1173

Mark my Bird!
That's great Mike! It's not often they feature a "Fast Ford" in MM&FF... I'll be buying that issue for sure, let us know when it's coming out. Congrats!
 
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