Carburator question

[lutry]

How are the emissions being tested?
Sorry for the stupid question, here is no emission for historic vehicles...

 

[Hedgehog]

Here it's tested at idle on the usual exhaust sniffing machine. Even thought it isn't necessary it does pass a running/driving test.

The engine stalls when driving with the clutch in, rolling to a stop sign for instance. She starts right up and will idle. At the very least an idle speed screw adjustment is in order. No matter what I am sure the high idle causing vacuum leak is taken care of and other than the slow idle the engine is running right well, best ever as a matter of fact. The engine has always popped and occasionally fired back when coming to a stop after a hard acceleration, occasionally it was a bit disconcerting. Various mechanics and carb. guys thought it was a leak in the exhaust. The manifold gaskets and the header to pipe gaskets are all new. Last night it wasn't doing any of that popping it did before.

 

[lutry]

Stupid question II:
Did you check the float level of the carb?

 

[Lumpy Grits]

HH-Die'n come'n up to a stop is also classic sign of a to low of a float setting.
May I suggest-
1 ck the idle mix screws are set the same number of turns out from their stop.
2 Back said screws(both)out 1/8 turn from where they are set now.
3 Up idle rpm to 750 +/- 25 rpm and see if that stops the die'n deal.
LG

 

[Hedgehog]

Lumpy/Lutry - It's NOT the float setting. Floats don't suddenly change their setting. Without being knocked around quite a bit. I have every intention to do steps 1-3 though. I'm at work and can't do anything until I get home tonight.

I think we are losing our focus here. We don't need to wander off into the underbrush looking for a problem. The point isn't that the carb. needs resetting, I know it does. Folks tried to compensate for a vacuum leak (the engine was running at high RPM and wasn't responding to adjustment as it should) by adjusting the carb. Now I believe the leak has been taken care of. Without the extra air from the leak the engine is idling poorly, as you would expect. I'm pleased by that. Now to bring the adjustments BACK to a normal condition and things will be good. Really, I'm sure of it.

 

[Lumpy Grits]

HH-Let us know.
BTW-Floats can and do go out of adjustment easily. Have had floats 'sink' because of a leak in a brass one and have had the plastic ones break. Common, NO, but it does happen.
Also-If you have messed with the fuel line fitting that goes into the carb's fuel bowl(tighten'd it)you have changed the float setting.
Hope all goes well-
LG

 

[lutry]

Sorry, I did not want to bother you.
I just had exactely the same issue, something in the
vacuum system and the carb detuned from the PO to
have it running.
I ended up rebuilding the carb, because I had to fully tune it anyhow.

http://www.jeep-cj.com/forums/f2/fuel-pump-removal-cj7-304-a-24697/

 

[Hedgehog]

BOTHER! Not at all. Looking for focus is all and I needed the chance to try what was already suggested. We all, including me try so hard to be helpful, sometimes we can lose track of the original problem. Now that I've had time to try the suggestions above. I might need the extra advice. ...... isn't that always the way it is.

The carb. is a fairly fresh professional rebuild from the folks I am calling my carb guy.

So, for an update. Last night I was not successful at stopping the stalling issue. I'm going to attack this in two fronts.

First the ERG valve I got is not what I would consider to be an original replacement, my fault really. I did not realize that ERG valves are very much vehicle specific. Today I'm ordering the correct one for my engine.

Second I'm taking it back to the carb. guys. They did more than a simple jet adjustment. They also adjusted the cold engine high idle mechanism somehow.

Further or a closer watch on the symptom shows that while cold the engine idles correctly, once warm the idle circuit isn't supplying fuel. Below 700rpm, when it's relying on the idle or low speed jets to do their job, the engine stutters hard wanting to run, then quits.

Lumpy - I tried setting the idle speed at 750rpm or so. Man that's just to fast, the jeep cruises around the neighborhood with no throttle required. Makes me nervous.

 

[lutry]

Which EGR did you buy?

 

[Neuner]

Even though I don't have a carb anymore - Hallelujah! I do find this interesting and informative.

From what you've said about your carb guy, I don't know if I'd trust him anymore. From what LG has described, I think you should give it a go yourself. Not knowing anything about carbs prior to owning mine, with the help of others, I got the muster to adjust, rebuild and tune mine and got it running pretty sweet. I was then able to tweak it as needed whenever it was needed. I know that if I can do it, you definitely should be able to do it easily.

On my AMC 258 i6 / 4.2l , which I know is a lot different, I also had mine idling at 550-600. Wrong or right, it was smooth and any higher, it appeared too much as you described.

 

[lutry]

BTW, I tuned mine exactely described in the FSM, now it runs really perfect.
If you need the full instructions for float Level, fast idle and all other settings,
I could provide them...

 

[Lumpy Grits]

Lutry-Just keep ask'n away. We are all here to help each other.
HH-What are you using for a tach? I ask because a 750 rpm idle for a manual tranny '8' ain't that high. Maybe try another tach-
PLEASE let us know what the carb guys find. Do ask them to ck the float setting.
Just for "c'it-n-grins"-Put the old EGR back in and see how it runs.
Fingers crossed for a good outcome.
LG

 

[Hedgehog]

Lutry - I've got a real Jeep Service manual that describes the procedure. I hate the way they say to go here, there, and the other place to find it though. One of my weaknesses is carb. work. Sure I know how to replace and set a float or turn the screw to set idle speed, but beyond that I get nervous. There is a bit in there about energizing the solenoid, what? I did do as Lumpy suggested. I turned the idle mixture jets in (pretty much exactly 1-360* turn) to the seat and brought both back out the same amount.

 

[lutry]

I worried about the solenoid as well, at the end of the day, I removed it
because I do not have an air condition...
Makes the adjustment much more easy, especially if you do not know if it works as it should...

 

[Lumpy Grits]

HH-Only 1 turn 'in' till stopped. Is that correct? WOW-that's very 'lean' in idle fuel mix.
I would start around 1 3/4-2 turns out. Give it a try.
LG

 

[Fastatv]

HH-Only 1 turn 'in' till stopped. Is that correct? WOW-that's very 'lean' in idle fuel mix.
I would start around 1 3/4-2 turns out. Give it a try.
LG

^^^^^^I agree with Lumpy, 1 turn from seat should be way too little ( lean ). I would actually start out at three turns from seat....get her warmed up and go from there. A vacuum gauge can be your friend here as well.

 

[Hedgehog]

I agree, before I get all worked up about investing another $140 in the proper EGR valve adding a few turns to the idle jet is definitely in order. No question about it the engine is running out of gas when it stalls. Again, even though I stumbled a little in my confidence this is exactly what should be happening with a vacuum leak taken care of.

A vacuum gauge is on the shopping list for this weekend. Can someone school me on how to use one for this? I will be looking in my shop manual, but I'm not sure the information is in there. Of course there is always youtube, EVERYTHING is on Youtube.

 

[Torxhead]

Hedge, have you seen Eric, The Car Guy? https://www.youtube.com/watch?v=oRrJQRtBNck

 

[Lumpy Grits]

Vacuum gauge is NOT necessary for idle mix adjustment. It IS handy.
You adjust BOTH mix screws equally each time, on a fully warmed up engine. and tune to the highest in/Hg on the gauge with a smooth idle. Only back the screws out(to enrich mix)1/8 of a turn at a time-
Attach V'gauge to any ported vacuum port at the carb's base.
You will need to 'tweak' the idle speed as you go about this.

X2 on using the old EGR valve.
LG

 

[Hedgehog]

Been watching youtube. Saw the Ericthecarguy video and others. Now I'm beginning to fell like I'm getting into the swing of this. Lumpy and others are right, all of the videos say to START with a adjustment of 2.5 turns. One even said that 2.5 turns was a factory setting. Since mine is at ~1 turn she most certainly is too lean to start with. This gives me an excuse to get a vacuum gauge so I believe I will.

Lumpy, the video guys say that you actually don't need to move each at the same time which is good because the drivers side screw with all the vacuum, water hoses, Air pump hoses and spark plug wires in the way is a bear to get to. I only want to deal with it once or so. It looks simple enough.

Warm engine up, now that I have a proper starting place it will be easier.

Install gauge to a vacuum port.

Turn the needle adjustment in or out until the rpm's are at the max ... they will start to fall when the adjustment is to far.

Reset the Idle speed and do the other needle the same way.

Adjust the idle speed and hit the road.

There was no mention of energizing a solenoid, where ever that little devil is.