Chevy truck rpms way too high

[hermit]

Hey all, I'm kinda new here. My comanche never gives my any trouble so I don't really have anything to post about usually. I am finally giving up trying to find a chevy forum that is as helpful as this one. So if yall don't mind, Ive got a chevy question for ya.

 

My truck is a 1977 K10 (4wd) with a 350 engine. its just a toy but seems like every day theres a new problem. So the current problem is this:

 

Its been sitting for a couple weeks due to a problem starting it. Finally got that fixed. turns out it was a wire that had pulled out of one of the plugs that plugs into the distributer cap. :wall: so simple. I know. anyway now that I got it started, it revs extremely high. (theres is no tach I'm just going by sound). I can put it in gear and if I let it, it would probobly idle down the road at about 20mph.

 

Now i kinda think it has something to do with the transmission because it has done this before and I checked the transmission fluid and it was really low (it has a leak) so I topped it off and the engine suddenly dropped back down to normal about 2 or 3 minutes later. That didn't work this time.

 

Now about 3 weeks ago, right before it stopped starting. i dropped the transfer case and tried to replace the rear transmission seal. I say tried because I put everything back together and it still leaks. :dunno: So I figure ill take it up to the shop for that, I'm not too good with transmissions.

 

Would transmission problems cause the engine to rev really high like that or is it just coinsidence that it stopped that one time and it is something else completly unrelated? I'm pretty sure I have the carb adjusted correctly and I don't think i have any vacume leaks.

 

Thanks for the help. I swear, if this thing wernt just a toy, I'd just hual it up to the junk yard. Ive had problems with it ever seince i got it. But on the plus side, theres a mechanic down the road that I take it to when it gets to dificult for me to fix on my own, and i think I am putting his son through college. Ha.

[vaquaro]

Look all your vacuum lines , disconnected ,cracked , leaking will cause high idle in any motor . Start at the intake and trace/follow each line ( and look for ports w/o hoses attached ) eg. to the transmission :eek: Let us know how you make out :wrench:

[JACKED88]

Hey all, I'm kinda new here. My comanche never gives my any trouble so I don't really have anything to post about usually. I am finally giving up trying to find a chevy forum that is as helpful as this one. So if yall don't mind, Ive got a chevy question for ya.

 

My truck is a 1977 K10 (4wd) with a 350 engine. its just a toy but seems like every day theres a new problem. So the current problem is this:

 

Its been sitting for a couple weeks due to a problem starting it. Finally got that fixed. turns out it was a wire that had pulled out of one of the plugs that plugs into the distributer cap. :wall: so simple. I know. anyway now that I got it started, it revs extremely high. (theres is no tach I'm just going by sound). I can put it in gear and if I let it, it would probobly idle down the road at about 20mph.

 

Now i kinda think it has something to do with the transmission because it has done this before and I checked the transmission fluid and it was really low (it has a leak) so I topped it off and the engine suddenly dropped back down to normal about 2 or 3 minutes later. That didn't work this time.

 

Now about 3 weeks ago, right before it stopped starting. i dropped the transfer case and tried to replace the rear transmission seal. I say tried because I put everything back together and it still leaks. :dunno: So I figure ill take it up to the shop for that, I'm not too good with transmissions.

 

Would transmission problems cause the engine to rev really high like that or is it just coinsidence that it stopped that one time and it is something else completly unrelated? I'm pretty sure I have the carb adjusted correctly and I don't think i have any vacume leaks.

 

Thanks for the help. I swear, if this thing wernt just a toy, I'd just hual it up to the junk yard. Ive had problems with it ever seince i got it. But on the plus side, theres a mechanic down the road that I take it to when it gets to dificult for me to fix on my own, and i think I am putting his son through college. Ha.

Agreed, do check all your vac lines. Its not a trans problem.

 

Now that the weather is cooler your choke could be sticking. Once running try quickly popping/stomping on and off the gas peddle. (repeat 2-3 times as needed) Doing so will usually deactivate the choke. If not, remove the air cleaner and open the choke by hand or with a screw driver. The choke is the metal flapper plate located inside the front two barrels of the carb.

On the side of the carb that black round thing controls the choke. It or the linkage to the choke can get sticky at times. Spray/clean everything with carb cleaner and see if that helps. If not you may need to adjust/back off on the choke a little. Its easy to do by simply loosening the mounting screws on the choke controller and rotating it a little. Can't remember now if you rotate it clockwise or counter clockwise. . I'm thinkin clockwise but you should be able to tell by looking at it.

 

Don't know what else to tell ya other than not to junk it. Considering it runs and drives I'm sure you could sell it. The trans and t/c alone are worth more than a junk yard will give you for it.

 

Hope this helped.

Robert

[JeffN]

Sounds like your choke is not opening keeping it on a high idle situation, make sure the choke is open after it is warmed up.

[kyleag89]

First off let me say....

Hey all, I'm kinda new here. My comanche never gives my any trouble

WHAT!? :hmm:

 

Never heard of a Comanche that doesn't give any trouble. I'm not too familiar with the older 350s but does it have the vacuum advanced distributor?

[hermit]

Man you guys are good! It was definatly the choke. I pulled the air filter off and wiggled the choke a little and all of a sudden the rpms dropped right back down to where they should be. I'm gonna pick up some carb cleaner on the way home from work in the morning and give it a couple shots of that and maybe a little WD-40 to keep it from sticking again.

 

Thanks for the help, I just kinda learn as I go with this truck. If it was my daily driver I probobally would have gotten fed up a long time ago, but sence its just a project it works out ok. A project car that always runs perfectly isnt much of a project.