I Need Old School Help Cj7 Idle!

[idontknow]

HI my name is james and i have a 78' cj7. it has a stock 304 with fender headers and almost all the vacume/air lines taken out along with any smog stuff that was ever there.

now the problem i am having is the thing wont idle. it wants to die every 2 seconds kinda like ppppppp..p..p..p..ppppppp...pp.p...p

i think its vacume related but all that stuff isnt there

any comments?

[ademster]

I would check to see if you fuel pump is producing the fuel pressure/volume required for your engine.

does it die all the time, on cold starts and when hot. or does it only die when hot, or cold.

when it is running do you hear any sort of hissing noise? like a vacuum leak?

Try using some starting fluid or brake clean while the engine is running and see if it idles. if nt then there is another issue!

do you have power brakes, meaning do you have a power booster? if so pull the hose off the booster and plug it... does it run better?

have you done any work to the engine lately, such as rebuild the carb or replace it? if so maybe the idle speed adjustment is to low.

above all whent he smog equipment was removed did all the vacum ports get plugged? or are they still as they were when the hoses were pulled off?

[idontknow]

i think its getting enough fuel but i dont know. when i give it some gas it runs fine for about 10 seconds then starts again.

it does it all the time

no real hissing but it does have a small exhaust leak

no power brakes

no engine work lately

and it looks like they plugged all the ports.


when i took off the pcv hose it smoothed out. but goes right back todiying when reinstalled

[Wildcat455]

Also check Spark plugs and plug wires.

Timing is correct?

Old Gas?

How long has the Carb been sitting? Or has it?

Sounds kinda like a lean condition, but then insufficient information given to really nail it down.

[Wildcat455]

Just read the part about the PCV hose.

So, when you remove the hose, is the PCV sill attached, or in the engine?

You might have more than one problem here, like accelerator pump inop and running rich.

Or something is jacked in your carb, and not allowing the idle circuit to function properly.

How's the tailpipe smell when it's running, like raw gas, or what?

Any smoke? What color?

[ademster]

I wonder if he has a clogged pcv valve that is clogged and cauing to much back pressure stalling the valves out... which could also be bad piston rings...

Honestly its tuff to figure out whats going on with out looking at it, hearing it, smelling it.

[Wildcat455]

Actually, I think a clogged PCV valve would do little in the way of Idle performance, except to make the motor run a little rich.

I could be way off base here, but Ima need mo info :D

[ademster]

thats true... Who knows like you said wildcat, we need more info

[idontknow]

the exhaust smells a little rich but its not putting out black smoke or any thing except a little blue out of one side.it burnes a little oil

changed pcv and nothing changed

its a daily driver so the carb hasnt been sitting

timming and gas are good and i just changed the plugs like 1000 miles ago so they should be fine

[ademster]

very weird...

Im to tired to think been packing my house up to move to PHX...

my head hurts..

and I am not done yet

[Jeep4ME]

Try spraying some carb cleaner (chemtool carb cleaner) around the base of the carb and intake manifold while the engine is running. Also around where the manifold bolts to the head. If there's a small vacuum leak the liquid from the cleaner will make the engine smooth out for a couple of seconds, it acts like a temporary plug in the hole. If nothing else it might clean off some of the gunk on the top of your motor.

Another thing is there an EGR valve on the engine. If it gets stuck open your engine will suck exhaust gas into the intake and make the engine idle really bad.

[OlneyJeeps]

where does Idontknow live?
what ignition system ar you using (prestolite=gold(color.... they aint worth crap) motocraft = silver box , or other (recently saw some weird conversion in points style distributor)?

[Wildcat455]

When he said it smoothes out and stays running when he pulls the PCV, he is creating a vaccuum leak that makes the motor run leaner, so i'm thinking it's not a vaccuum problem.

Recheck your firing order from the plug changeout, just so we can eliminate that.

Did you gap your plugs when you changed them?

Will the motor rev at all?

If so, find a towel or a T-shirt, rev the motor up, (the butterflies have to be opened up almost all the way for this.) and then quickly place the towel or t-shirt over the top of the carburetor, sealing it off. that will create a low/high - pressure/vaccuum differential inside your carburetor, and may suck loose something that is clogging it in the idle circuit.

You may have to do this more than once to clear it.

It's a gross analogy, but it's similar to sniffing your nose really hard and launching that booger down your throat, making you cough...:eek:

I told you it was gross...:rolleyes:


Good luck, and if all else fails, get someone over there that can help you diagnose it.

[NVRSTUKXJ]

could it be a bad gasket between the carb and the intake leaking????....try tightening the bolts that attach the carb to the intake.....

[Last_Renegade]

What kind of carb is it???? I had the Carter on my CJ and i had idle issues also.
Turned out it was the idler tubes. Every time i had to stop it wanted to cut out.

[drroadie]

I think Last Renegade is on the right track. Pulling the PCV hose off leans out the mixture, which indacates a rich mixture with the hose connected. If it where mine, I would be checking the idle circut in the carb. Sounds like it is dumping too much fuel in at idle. Let it idle as long as it will till it dies, then pull a few plugs and check color and if they are dry or wet with fuel. Good luck with it.
Don

[Last_Renegade]

Heres the link for the site that helped me out......

http://www.offroaders.com/tech/jeep/engine-carter.htm

Hope it helps for you too

[idontknow]

i didnt know what an idle circut was so i just took the whole carb apart and cleaned any where that looked like a fuel passage. now it seems to be running fine but lets see what daily driving loosens up!

[Wildcat455]

I think Last Renegade is on the right track. Pulling the PCV hose off leans out the mixture, which indacates a rich mixture with the hose connected. If it where mine, I would be checking the idle circut in the carb. Sounds like it is dumping too much fuel in at idle. Let it idle as long as it will till it dies, then pull a few plugs and check color and if they are dry or wet with fuel. Good luck with it.
Don

Where did Last Renegade say this?? :rolleyes: