I think my secondary throttle valve is sticking or linkage is wrong can you help?

TWP2459

MEMBER
1993 ISUZU TRUCK
187,000 MILES

About 3 week ago I was on the interstate. As I was going on a exit ramp my engines rpm would not throttle down. It is like it is running at full throttle. Since I have tow it home it is still doing it. From what I can tell is that the linkage on the cable is alright. Could a secondary throttle valve be stuck wide open or is it suppose to saty open please reply in detail please

3 Replies

BILLYMAC

MECHANIC
2,204 POSTS

Hi is your truck fuel injected or carburator?

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Monday, February 20th, 2012 AT 10:00 PM

TWP2459

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9 POSTS

Carburator

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Monday, February 20th, 2012 AT 10:33 PM

BILLYMAC

MECHANIC
2,204 POSTS

If you disconnect the accel cable will it still idle high? The primary and secondary throttle plates should open and close at the same time. But even if linkage became disconnected it would not let fuel into the bore until accelarator was pushed. So if it is doing this then the float has to be stuck open and flooding eng it is not flooding because eg is burning the fuel ence very high idle.

Move the throttle and watch and see if it is moving the plates also watch and see if it is spraying fuel in the bore only when you move the accell. It is prob dumping a lot of fuel even if you don't pat the accel.

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Monday, February 20th, 2012 AT 11:09 PM