Accufab plenum % TB problems

GTGene

Founding Member
Mar 19, 2002
216
0
0
Eagle, Idaho
Hey, I just installed an accufab plenum and accufab 70 mm throttle body last night on my 02. After the install now sometimes it will get stuck at 2000 rpm while driving, then If rev it up real quickly, it will go back down. I cut the throttle body spring a little to make it tighter, but its still doing it. Anyone had this problem?

Also, now my check engine light is on and I was wondering if the plenum/tb reacted with my densecharger fenderwell cai to make it run too lean? What do you guys think?

Other than those two problems, its definately feels good mid range--->high rpm!
 
I know the problem I have the same problem with mine!!
it's the tps
throttle postion switch
Ok if you take the switch back off the T/B you will see it moving becuse the computer is tring to compensate for the new stuff soo much that the switch is going nuts!
If you take it off or unplug it the service engine light will come on BUT the problem will go away.
Take the switch to ford adn just get a new one and it will be fine.
the ford dealer told me the stock switch is JUNK!
so the replacement switch will be PERFECT!
Hope this helps
 
03Sleeper - Are you refering to the Throttle Position Sensor (TPS)? If that's the case, before scrapping it for a new one check your voltage - with the throttle body at rest (closed) it should read .98-.99 volts on the center wire.
This is the idle voltage the computer is looking for. If it is reading high or low, grind out the holes a little so you can rotate it until you get this voltage and then tighten the screws.

Both problems could possibly be the result of a loose vacuum connection - did you reconnect the EGR properly?

Just a couple thoughts.

Jay
 
Gotta quick question on checking the TPS voltage as I’m about to change out my TB Plenum combo.

When you check for voltage do you do this while the car is idling or off with the ignition in the on position or does it matter?

Thanks,
-Cale
 
281Ponies said:
Gotta quick question on checking the TPS voltage as I’m about to change out my TB Plenum combo.

When you check for voltage do you do this while the car is idling or off with the ignition in the on position or does it matter?

Thanks,
-Cale

Engine does not have to be on. Turn the key to the ON position.
 
If you put the positive probe on the middle wire and the ground probe on the strut tower (somewhere bare metal or grounded) you should get .98V - .99V with the key in the on position, whether the car is running or not - as you open the throttle body the voltage will increase - at WOT it will be up near 5V.

Also, if you make changes to the TPS make sure you disconnect the battery and let the computer re-learn the changes. Otherwise, an increase in TPS voltage without resetting the EEC will create a high idle because the computer thinks you're giving it gas.

Jay

By the way, the book calls for .98V - .99V, but my car idles best at .95V, go figure - at .98V my car seems to "hunt" and the idle isn't stable. It jumps to 900 RPM and settles in at 700 RPM - point being, it may take a little experimentation.
 
I installed my C&L Plenum and Accufab 75MM TB and didn't have any problems like you are describing but I did notice that the black cable that runs with the throttle cable, I think it is the Cruise Control Cable, maybe. It is totally black and connects right underneath the throttle cable at the throttle body. Anyways I noticed that when I opened and closed the throttle body, that the black cable, which has a little square black plastic piece about 4-5 inches down on it, would get snagged or slowed down by the hose that connects to the rear of the plenum. Just a thought as to why your hanging your RPM while driving slow and not fast.
 
GTGene said:
Hey, I just installed an accufab plenum and accufab 70 mm throttle body last night on my 02. After the install now sometimes it will get stuck at 2000 rpm while driving, then If rev it up real quickly, it will go back down. I cut the throttle body spring a little to make it tighter, but its still doing it. Anyone had this problem?

Also, now my check engine light is on and I was wondering if the plenum/tb reacted with my densecharger fenderwell cai to make it run too lean? What do you guys think?

Other than those two problems, its definately feels good mid range--->high rpm!
Sounds like a vacuum leak. Mine behaved the same way and the codes were all related - 2 were o2 sensor (lean) and the other was about the idle being too high. The tub that connects to the back of the plenum was leaking.
 
so I did have a vacuum leak at the EGR and fixed that up, then i went to autozone to check the codes, it spat out a 1131 and a 1151.

1131 is P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.

1151 is P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2.

Now is that because of the combination of hte densecharger+plenum/tb or just because of the egr vacuum leak? Should I swap the cai out?
 
disconnect your battery for 10 minutes. step on the brake pedal a few times with the batt disconnected to drain all the electricity out of the system. then reconnect everything. :)