Help!!

[adamsj13]

Hello all, My 86 Jimmy full size seems to Idle high when it has been running for a while. When I turn it off, it sputters some. Sometimes more than others.

Another thing, When I let go of the breaks it seems to take off with out giving it gas.(more than it should, I think). Then when I give it gas, It seems to go for a second then hesitates. Another thing when I put it in gear, it really jumps hard. I have check the automatice transmission fluid and it seems fine. Thanks again for all your help!!

Jared..

[Beefy's Bronco]

86? I am no chevy expert, so, does that thing have a carb or is it injected? How about a computer? If it is computerized you can get the codes easily enough. I would say carb if it has one. The stumbling your are speaking of is called "run on" or "dieseling" and can be caused by high idle or heat. Check for vacuum leaks as they can also cause your high idle condition especially if you running a little rich.

[adamsj13]

Its Carburated, Its a new refurbished carb. They adjusted the Idle for me. This was a week ago. Not sure how computerized it is. The carb has a electric chock. What is the best way to see or find vacuum leaks? When it is Dieseling it is running at normal running speeds. The themp gage says its about 190 degrees.

Any Ideas about it when putting it into gear/ or When I let go of the breaks it seems to take off with out giving it gas.(more than it should, I think). Then when I give it gas, It seems to go for a second then hesitates.

Could my timming be off or are these not the symptoms?

[Beefy's Bronco]

Your timing could be off and I would check it. I would try to adjust the idle speed when the engine is warm. It is supposed to idle fast when the engine is cold, but when warm the idle should be slower. Around 650 to 700 rpm's. Look on your radiator support. There should be a sticker that will give you all sorts of info. Look for your idle settings. Also get a repair manual (Chilton or Haynes) they are cheap and will hold a wealth of info for you.

To check for vacuum leaks, get a can of WD-40 or use a propane torch, turn it on but dont light it, and spray or run the torch around the base of the carb, around the intake manifold and all your vacuum lines. Visually inspect all your lines. Did you pay for a carb gasket? Some rebuilt carbs come with them but if you didn't pay for one you probably didn't get one. The carb gasket should always be replaced when you replace your carb. I change them when ever I take the carb off as they take a set and they will leak on ya.

The problem with your transmissions hard engagement is probably due to the fast idle. My opinion. Some one else may have some other ideas on the subject. Check back often.

I caution folks not to light the torch because I know a guy who did and his carb was leaking gas. You get the picture. The damage was very minimal but could have been worse.

There are other guys here who are allot smarter then I so make sure ya check back for their ideas

[Beefy's Bronco]

Originally posted by Beefy's Bronco
Your timing could be off and I would check it. I would try to adjust the idle speed when the engine is warm. It is supposed to idle fast when the engine is cold, but when warm the idle should be slower. Around 650 to 700 rpm's. Look on your radiator support. There should be a sticker that will give you all sorts of info. Look for your idle settings. Also get a repair manual (Chilton or Haynes) they are cheap and will hold a wealth of info for you.

To check for vacuum leaks, get a can of WD-40 or use a propane torch, turn it on but dont light it, and spray or run the torch around the base of the carb, around the intake manifold and all your vacuum lines. Visually inspect all your lines. Did you pay for a carb gasket? Some rebuilt carbs come with them but if you didn't pay for one you probably didn't get one. The carb gasket should always be replaced when you replace your carb. I change them when ever I take the carb off as they take a set and they will leak on ya.

The problem with your transmissions hard engagement is probably due to the fast idle. My opinion. Some one else may have some other ideas on the subject. Check back often.

I caution folks not to light the torch because I know a guy who did and his carb was leaking gas. You get the picture. The damage was very minimal but could have been worse.

There are other guys here who are allot smarter then I so make sure ya check back for their ideas

DOH !!!
I forgot to tell you that with a propane torch, when and if you find a vacuum leak your idle speed will increase. The engine has to be running (forgot that part too). I dont know what changes will take place when you use carb cleaner or WD-40 to check as I have only heard of these methods and have never used them. Propane torch is cheap and less messy though. LOL

Cool, I finally learned how to do that quote thingy.

[bbcamp]

Also check the throttle linkage. The Edelbrock linkage is a little foward of stock, so it needs adjustment.


And make sure the throttle return spring is installed correctly. :)


On any new carb, you may need to tune it. A little stumble when you get started may be a signal that the accelerator pump linkage needs tweaking.

Tuning and tweaking are explained in your carb's owner's manual. Read it.

One other thing. Carb tuning is a waste of time if you have: a dirty fuel or air filter, the incorrect timing and dwell, bad plugs and wires, leaky vacuum hoses, bad gaskets. (I may have mentioned these in a previous post)

Go the autoparts store or Sears and get an engine analyzer (not a computer code reader) and timing light. You can do almost any diagnostic test you need with these tools, their owner's manuals and your truck's shop manual.

[adamsj13]

Hi, I have a reburbished quadrojet, Like the stock one. It came with a new filter and all the gaskets. The auto parts store said I need a new Distributor if I go with Edelbrock. Thanks again for all the info.

[bbcamp]

Oh. Uh, you're welcome!

[Beefy's Bronco]

Ummmmm......... The Quadr-o-junk Carb was built by Rochester.
Where did we get Edelbrock at? What Mr. Camp said is correct. You have to tune after you fix any problems you may find. Who installed this thing for ya? I'd take it back and have 'em check it out.

[adamsj13]

i installed it. where i bought it they adjusted it for me.

the edelbrock was a post i did last week, and i ended up going with rochester