Throttle not closing

[mlebauer]

Today I fired up the 2001 Challenger and was pleased that both engines ran well, at least on trailer. :hurray:
Then I was dismayed to find the right engine throttle wasn't closing when I pulled back the lever.:banghead: No trip to the river this week.

I can close the throttle by hand but it felt stiff. So I removed the flame arrestor to see what's going on. I discovered there is a spring loaded lever under the intake manifold connected to the engine block. It has a cable connected to the throttle lever, it appears designed to pull the lever back to the closed position when you pull back the lever. Is that all it's for?

The spring on that lever only has tension for the first half inch or so, after that it floats. I tried reaching under and turn the spring, but was unable to attach it to anything (and killed my fingers in the process).

Is that the only function of that lever below the intake manifold? Is the unloaded spring why my throttle won't close on its own? If so, how can I tension its spring?

 

[Dr Honda]

The cable going down to the engine block is opening, and closing the oil injection pump.

The throttle return, is a spring mounted on the MAG carb.

If you have a bind... you will need to disconnect both cables, and figure out where the bind is.

 

[mlebauer]

The cable going down to the engine block is opening, and closing the oil injection pump.

The throttle return, is a spring mounted on the MAG carb.

If you have a bind... you will need to disconnect both cables, and figure out where the bind is.

I was guessing that may be the oil injection. I don't think there's a bind, rather the spring on the oil injection lever isn't tensioned. The cables are all moving well. How can you get those springs re-tensioned? Any special tool? Do I need to remove the oil injector lever to do it?

 

[smc0922]

There is a return spring on the throttle valve shaft on the carb. Youre problem isnt likely at the injection pump.

If you remove the throttle cable off the carb does it still do it? Yes its a carb issue, no its a cable issue.

The PO of my GTXL put two different throttle cables in it, come to find out the throttle shaft was bound up in the bushing. Cost him $500 of his asking price when I bought it (he lowered the price when I asked him how much and I did not complain )

 

[mlebauer]

There is a return spring on the throttle valve shaft on the carb. Youre problem isnt likely at the injection pump.

The injection pump shaft spring isn't fully tensioned, it's not returning either.

If you remove the throttle cable off the carb does it still do it? Yes its a carb issue, no its a cable issue.

While I didn't remove the throttle cable, I pulled back the cable so there's slack and it still didn't return.

The throttle doesn't turn easily even with no tension. Maybe there's a problem with the shaft?

 

[smc0922]

The injection pump shaft spring isn't fully tensioned, it's not returning either.


While I didn't remove the throttle cable, I pulled back the cable so there's slack and it still didn't return.

The throttle doesn't turn easily even with no tension. Maybe there's a problem with the shaft?

BINGO!!!

FYI the injection pump arm is only sprung to open fully if there is a cable failure, it is not sprung to close. Thats why youre saying its not fully tensioned. That is correct.

 

[mlebauer]

FYI the injection pump arm is only sprung to open fully if there is a cable failure, it is not sprung to close. Thats why youre saying its not fully tensioned. That is correct.

Good to know! I'd thought they were sprung to move together. Now I don't have to break my finger turning that spring.

BINGO!!!

Okaay, guess I have to remove the carb and dowse it in PB Blaster? If I take it off maybe should just get the ?!@# thing rebuilt.

 

[smc0922]

It's likely the throttle shaft needs to be removed and cleaned up. I'd recommend replacing the bushings as well. Once the carb is out its simple to pull the shaft. Just be aware of the spring tension and position on the shaft.

 

[mlebauer]

It's likely the throttle shaft needs to be removed and cleaned up. I'd recommend replacing the bushings as well. Once the carb is out its simple to pull the shaft. Just be aware of the spring tension and position on the shaft.

Project for next weekend. Thanks for your help!

 

[mlebauer]

Ok, it's all done. Turns out the throttle cable was jacked too. Carb throttle sticky but not bad...PB plaster and a lot of back & forth with a vice grip got it turning well again. Throttle cable a real PIA to install, it's tight under the steering wheel to connect that extra link for the hard steering throttle surge. Setting idle speed was finicky, but got it locked at 2K rpm on the trailer.

Used all the boat time to finally get my Hawkeye depth finder installed. I bought a transom mount transducer. The extra through connector son the right engine is the perfect place to route the cable. I got the connector for the speed cable, drilled a small hole, cut the transducer cable near the front connector.

Can't wait to get it out on the water first time, to see if I did everything right. After relining pumps late last season and more responsive right engine from the throttle cable, plus less grounding risk with the depth finder, it should be a nice ride.