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Old 10-17-2020, 11:01 PM   #1
mschultz373
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Default throttle cable not creating WOT

basically, my gas pedal fully depressed is not creating wide open throttle. the throttle plate has significant travel left with pedal fully depressed. it does not appear that adjusting the cable sheath (mounted on intake manifold) is changing this condition. does this mean I need to trim the throttle cable at the pedal inside the driver footwell? or?

just to confirm, my throttle pulley spools are (from valve cover to driver side fender): kickdown cable, throttle cable, cruise cable.

EDIT: here's a photo of the plate with gas pedal fully depressed:

throttle-plate

Last edited by mschultz373; 10-17-2020 at 11:11 PM..
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Old 10-17-2020, 11:04 PM   #2
Harlard
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Doubt that you are actually having that much of an issue. These throttle bodies allow deflection far past minimum surface area. Take the intake boot off and look at the butterfly valve's position with the pedal fully depressed.
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Old 10-17-2020, 11:12 PM   #3
mschultz373
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Old 10-17-2020, 11:12 PM   #4
mschultz373
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just tried posting a photo... throttle butterfly valve looks pretty closed. that's with the pedal fully depressed.

throttle-plate



my idle is lumpy AF so I've thought I'm running pretty rich. if this looks like a problem, that would appear to be the culprit - restricted air.
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Old 10-18-2020, 02:13 AM   #5
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Originally Posted by mschultz373 View Post
my idle is lumpy AF so I've thought I'm running pretty rich. if this looks like a problem, that would appear to be the culprit - restricted air.
No, that just tells the engine that you're technically only pressing the pedal part-way down.

The throttle cable attaches to the spool and turns it.
The spool pulls on a short link that's connected to the throttle plate.
The spool should have some built-in "stops" at either end of its travel.

With the cable disconnected (or really slack), does the spool contact its "idle" stop?
With the spool cranked, does it contact the "WOT" stop?
On my 740, there's an idle "boss" on the spool that contacts the mounting bracket.
Another "boss" is used as the WOT stop.

If they both contact, and give idle and WOT at the throttle plate, the only three other things to check are the pedal, the cable, and the environment.

1 - With the spool on the idle stop, and the cable tight at the spool (but not actually turning it yet), is the top end of the throttle pedal assembly (where the cable attaches) right against the firewall under the dash?

2a - If no, something is binding. The cable is probably frayed inside.
2b - If yes, does flooring the pedal move the spool to its WOT stop?

3a - If yes, everything's fine. Quitcher bitchin'.
3b - If no, how many floor mats are under the pedal (environment) restricting the pedal's travel?
3c - If no, is the pedal assembly bent (unless it's plastic), so the pedal is too close to the floor to start with?
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Old 10-18-2020, 11:29 AM   #6
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thanks for the help. i got it figured. had the kickdown adjusted way too tight and wouldn't let spool get to WOT.
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