Re: Odd starting problem

By the fact you can start it by mashing the pedal down, sounds like the carb is leaking fuel down. Mashing it helps more air get in to start it. The smoke verifies that.

Yes, you'd think it would be black smoke - some of it is, but lots of fuel cranked into the exhaust system without burning - the white smoke is vaporized fuel - warmed, but not ignited. Black means it partially burned.

The floats have sunk or the bowl is cracked or leaking.

Try swapping in a new set of floats.

Caution - the foam type floats have a thin coating on them to seal them. Touching them with your fingers can cause that coating to dissolve. Best use a paper towel or something to not touch them during installation.

 

Re: Odd starting problem

RRICH,

That makes perfect sense. I have an extra float lying around so I will try that now. The cracked carb body would certainly be less fun to deal with.

Thanks for the advice. I will let you know what I find.

 

Re: Odd starting problem

If you pull it off - there might be little lead plugs on the bottom where they drill the passages, then they plug the outer end.

Sometimes they get loose and leak. JB weld smeared over them works great - clean and rough it up first. But - there not be any on that carb - I don't remember.

 

Re: Odd starting problem

Does it crank a while, then 'catch' as you let off the key?
If so the 'Start' circuit isn't working in your igntion module for some reason.

If the float sinks, you will have fuel comming out of the float bowl vent.

If it were seriously flooding, for what ever reason, the plugs would get wet and you would have to let it sit for hours to dry out the chambers...

Black smoke, too much fuel.
Blue smoke, oil in the chamber.
White smoke, antifreeze in the chamber.
Steam, water in the chamber.

 

Re: Odd starting problem

Junk Yard - I am familiar with what you are saying about the start/crank circuit issue. I did have that exact problem with another CJ of mine and I was able to start it by letting the key 'snap' back. This does not appear to be similar. I have tried to see if I can force it to start by snapping the key back. It still seems to only start on the fourth or fifth try/crank by holding down the gas pedal.

I did replace the float and that did not solve anything. Now I can shut off the engine, wait a few seconds, and the exact same thing will occur, requiring four or five crank attempts. If fuel we leaking down would it occur this fast after shutting the engine off?

Could it be a flat spot on the starter and it just takes a few tries to get it in the right position to engage?

 

Re: Odd starting problem

The smoke colors - yes, and no.

I'll explain it a bit better.

Black smoke indicates the fuel is burning, just way too rich. But it has to burn to be black.

Raw gas, just vaporizing (hot but no fire) but not actually burning steams off white in color.
Just like when you toss on more charcoal lighter on a hot BBQ that went out - and it doesn't light yet. It steams up white vapor - then when you toss the match - Whoosh! Once it starts burning the carbon is liberated from it and it burns black at first. But it takes actual burning to get the black.

Soo - if it's dripping bad when he stops it, that extra fuel gets down in the chamber, wetting the plugs. As soon as he cranks it, some of that raw liquid gas gets out the exhaust valve at first - liquid, unburned. After cranking a moment with the throttle open the plugs clean up enough to start firing. Once it starts firing - it's still too rich - it makes the black smoke - and the gasses are hot but not so hot as to get the raw gas in the exhaust to catch fire - so it just vaporizes to the white steam. The first puff out the pipe is white, then black, just like he described.

As the float begins to sink over time, the fuel level rises in the bowls. If it's just sinking a little, the level rises only a little. That can be enough for it to spill over into the main wells, but not quite high enough to come out the vents.
So when it's running it's a little rich all the time. Shut it off, that extra level spills into the wells, and the residual pressure in the fuel lines keeps on feeding more into the bowl until it's depleted. That could be almost a 1/2 a cup of fuel!

Usually if the bowl level is high enough to spill out the vents, it won't start, and if it does, it runs really bad.

But then like you said, it may be as simple as the bypass circuit - the wire might have fallen off the solenoid if it's a push-on type.

He He - nowdays with fuel addatives, cat converters etc, the old diagnosis by color can lead us astray.
We used to look for that beautiful blue gray exhaust pipe - now if we get it we have problems. Black is the word, but you actually have to feel it to make sure it's not sticky/oily!
It used to be the same way with a mild grey plug, now it's brown!
Super Clean plugs meant a tad too lean - now it's good!

Too much oil in a Cat that still works comes out black smoke.

(Look at an old oil burning smudge pot - black, not grey.
Sooooo - that means computerized cars with cats are just glorified smudge pots now!

This new technology - it may be good, but it comes with new rules!

 

Re: Odd starting problem

Unburnt fuel and oil will each leave a residue in the tailpipe; they can look similar. If you wipe your finger around the inside of the tail pipe oil will feel ... well... oily. Unburnt fuel will have a velvety feel to it, and not a greasy - oily feel.

So, there's another way to tell if the engine is blowing fuel or oil.

 

Re: Odd starting problem

[ QUOTE ]
Could it be a flat spot on the starter and it just takes a few tries to get it in the right position to engage?

[/ QUOTE ]

What we have here is a failure to communicate. (Actually multiple since JYG got involved.)

That's where I thought you were going when I read your original post but then you went into fuel and all that. Does your statement, "But it does not catch." refer to the starter engaging the flywheel or the engine starting even though the starter is cranking it over? Does the starter crank the engine over on every try?

Based on your question above, and that it is a 258, and that 258s are notorious for oil leaks at the rear of the valve cover, and that the oil from said leak is slung around by the flywheel, and that dirt gets stuck in the oil … I think you get the picture.

 

Re: Odd starting problem

He He -- For sure LEVE - look, feel, smell -- but I draw the line at tasting!

What do you do if it tastes like p-nut butter?

 

Re: Odd starting problem

"Could it be a flat spot on the starter and it just takes a few tries to get it in the right position to engage? "

Nope, you said it's cranking just fine.
Might be a starter solenoid on it's way out...

Try this, even though it's cranking fine, hook some jumper cables up to it and another vehicle. Second vehicle running.
The second vehicle's alternator should kick your system up to about 14 volts.
That will find a bad module or bad module ground in a hurry.

Turning the engine faster will get you a better signal from a weak distributor pick up coil...
-----------

Another little trick is shoot it with starting fluid and crank.

Getting fuel from the accelerator pump isn't a test of the carb.
The actual idle passages can be completely clogged and the accelerator pump will still work and shoot fuel.

Cranking, then cranking again, then cranking again before starting can also be symptoms of a low or dry float bowl.
The float bowl can be bone dry and still have one or two accelerator pump shots in the accelerator pump.
Starting fluid will find a weak fuel pump also.

If there is ANY spark, the starting fluid will find your problem!
------------------

Personally, I'm leaning towards ignition problems...
The float bowl shouldn't go dry in a few minutes, and you say you can drive this thing, shut it off for a few minutes, and it will do the same thing again.
That isn't a fuel delivery problem or a seepage problem...
------------------

Random thoughts (hope my head doesn't catch fire...)

Might also be a module or Distributor mag trigger on the way out...

I think you need to find out what it Isn't getting when you are cranking and it's not staring...(Air/Fuel/Spark)

Get you a good old test light and add about six feet of wire to it...
Plug into the red, then the white module wires and crank away.
If you are getting current to the 'White Wire' when cranking, it isn't the 'Start' circuit.
Red may, or may not, be hot during cranking, but should be hot with the key in the 'Run' Position.

Plug into the Green module wire and crank.
If the light don't flash, the module is done or the distributor mag trigger is shot.

 

Re: Odd starting problem

[ QUOTE ]
He He -- For sure LEVE - look, feel, smell -- but I draw the line at tasting!

What do you do if it tastes like p-nut butter?

[/ QUOTE ]Test equipment? We don't need no stinkin' test equipment!

I have diagnosed blown head gaskets by tasting the exhaust. Just waft your hand through the exhaust and touch the tip of your tongue to the palm of your hand. If there's coolant in the exhaust you can taste it far sooner than you can smell it.

If it tastes like peanut butter:

• Wash Your Hands, or
• Get the peanut oil out of the fuel

 

Re: Odd starting problem

I do believe it is cranking. It even seems to rev for a split second but does not continue. I will try the test JYG suggested this evening.

Question: if it is a fuel delivery problem, then I assume it would not roll start (dump clutch on downhill roll), is this correct? I have not tried that yet but thought it might be worthwhile. If however it roll starts then I assume that would point more towards electronic issues?

 

Re: Odd starting problem

If you can bump start it, then it's a problem with the starter assembly, or the start circuit.

 

Re: Odd starting problem

[ QUOTE ]
Nope, you said it's cranking just fine.

[/ QUOTE ]
Where'd he say dat?

 

Re: Odd starting problem

[ QUOTE ]
I do believe it is cranking.

[/ QUOTE ]
That's a pretty important thing to KNOW. Have somebody watch the front of the engine to make sure the belts are turning when you crank it if you cannot tell from the sound of the starter.

 

Re: Odd starting problem

TAZ I do 'think' it is cranking, at least I can hear the starter spin. But perhaps it is not making contact to the flywheel is what I believe your point may be.

I think I may try to pull the starter from my other CJ and swap just for grins. Two bolts on and off it is an easy test.

 

Re: Odd starting problem

[ QUOTE ]
TAZ I do 'think' it is cranking, at least I can hear the starter spin.

[/ QUOTE ]
The word "spin" is what bothers me about that statement.

 

Re: Odd starting problem

From the original post === What he said!

"""""Shut down the engine, wait a couple of minutes and then again I will have to mash the accerator to the floor, crank four or five times, and then bingo it starts"""""""""""""

He He - but opinions -- all over the place! Good, It shows folks are thinking.

If he "shut it down," it must have been running - so it had fuel in the bowl at that time.

But if the bowl is dry after only a couple of minutes - where did the fuel go? The space aliens stole it? Or did it drain down into the cylinders?

If he can restart it by mashing the accelerator to the floor - (Computer systems call that "Clear Flood) - doesn't that indicate it was flooded? How do you start a flooded engine?

How can he "crank" it 4 or 5 times if the starter isn't engaging, why - or rather how - did it eventually start without being turned by the starter? Thjose space aliens again?

If the solenoid is not working, how did it crank and then eventually start?

He said he "sees gas" - even when the float bowl empties out, there's still 2 or 3 shots of fuel in the accelerator pump well. Is that what he "sees?"
One or two pumps would get it fired, then the bowl fills and it keeps on running.
But if it's flooded at first, wouldn't that keep it from starting at first - till "clear flood."

It could be the ignition bypass is not working - but holding the pedal to the floor makes it start? Ah, bypass wire's caught on the linkage?

I'm surprised nobody mentioned the right front tire pressure.

LOGIC!

But let's see how it turns out!

 

Re: Odd starting problem

The long crank time could indicate an empty carb. It would take that long to refill it. (4-5 cranking attempts). OTOH, you said you see fuel (did you say?) squirting when you move the throttle ..which would indicate that it's not ..unless the accellerator pump is somehow sequestered fuel for a couple of pumps.

 

UPDATE - FIXED

Ok, so after taking note of all the things mentioned here is what I have done.

I swapped the starter from my other CJ and the symptoms (not starting) remained the same. Thus I have ruled out the starter.

I let the jeep set for an hour then opened up the top of the carb to see if the bowl was empty or if the float was low letting gas seep down. I measured the level of the fuel and after 30 minutes it remained the same. The needle was firmly seated the entire time. Thus I ruled out empty bowl or leaking fuel (although a crack could be an issue).

Then I replaced the starter selenoid (I had a new spare), and what do you know...THAT WAS THE PROBLEM. After installing the new selenoid I successfully started the engine on the first crank about twenty times.

OK, now that it works I am still puzzled as to why the symptoms seemed (at least to me and a few others) to point to something else. Why did it typically start after the forth or fifth crank? Why did holding the pedal to the floor 'appear' to help. I have always thought a bad selenoid either clicked, whirred, or did nothing. Obviously I learned something. So by way of a post incident report I would like to hear your opinions.

Finally, let me say a huge THANK YOU to everyone for the comments, advice, and suggestions. I really do appreciate it more for the fact of what I learn than actually repairing the issue. Every time I think I know something, you guys amaze me with your detailed knowledge. Hopefully I can repay with some knowledge of my own in the future.

 

Re: Odd starting problem

???
Check the first line on my second post. (after I quote you)

 

Re: UPDATE - FIXED

[ QUOTE ]
OK, now that it works I am still puzzled as to why the symptoms seemed (at least to me and a few others) to point to something else.

[/ QUOTE ]

Do you REALLY want an answer to that?

 

Re: UPDATE - FIXED

Does a starter solenoid turn the contacts inside every time it engages? The ones I've torn apart are round and there are arcing marks evenly across the disk. I'm assuming the disk rotates so after 4 or 5 times it gets to a good contact area.

Why not drill out the rivets and see what is inside.

 

Re: UPDATE - FIXED

JYG, yep you did point out the selenoid as a possibility, that was why it was on my hit list of things to check. Thanks again.

TAZ - Yes I really do want an answer. This, to me, is not about who was right or wrong, but how to collectively learn from the experience. I don't mind being wrong or listening to healthy debate. Next time I, or someone else on the board, have a similar starting problem I will remember this situation and may be able to help. I thank you for your input as well, everyone made me think about this.

 

Re: UPDATE - FIXED

OK, in the interest of constructive criticism to promote your learning and not meant nor should be taken as flaming:

You were all over the place. You weren't even sure that the starter was turning the engine over.

Your communications were all over the place, which lead people down the wrong paths.

Even now do you know what was wrong? Changing the solenoid fixed the problem but were the solenoid starter contacts bad enough to not spin the starter fast enough to throw out the Bendix or was it the ignition contact that was bad? Was the solenoid even bad or was it just a bad ground or a bad connection somewhere on one of the solenoid posts?

I asked if the starter was turning the engine over. JYG asked if it actually started with the key in the start position or only when you let it return to the run position. If indeed the solenoid was the problem, the answer was there several posts back.