always surgeing

doubleR

doubleR

Member
My 68 1100c, has the 266, 3-speed, early this year a new reman Holley 2300, (7448) 350 cfm. A couple of weeks ago a cardone Holley dist. Points at 19 thou. Timing set at 5deg. Btdc, new coil, wires and plugs last year. While driving it does not matter what speed, it is constantly surgeing, driving me bonkers. I have tried turning the idle air screws out, have gone up to 2 1/4 turns have gone in to just under 1 doesn't help. Have tried devanceing to 0 and advanceing up to 10 deg. Btdc.
A little history on the truck, it sat in a garage for 20yrs before I got it a cpl yrs ago. Put a new paint job on it last winter along with other stuff to get it looking good for this summer, but it is not a treat to drive right now, the reason for the new dizzy is I was constantly messin with the curb idle, I think all those yrs sittin the vac. Adv. Was sticky.
I live in flat northern oh, so no altitude problems.
Please help the ol girl to be the smooth running machine I hear tales of.
 
Does it idle smoothly?

Have you cleaned out the gas tank(s)?

Have you cleaned out the fuel lines?

Have you checked / replaced all the rubber fuel line connectors?

Have you replaced the fuel filter?

Have you tested the fuel pump pressure?
 
Idles fairly smooth and you can rev it up easily. The gas tank was taken to a radiator shop and boiled out. The fuel filter is a cpl. Years old, but not alot of miles in that cpl. Yrs. The 1 piece of rubber hose the fuel line has is new. I should also note that the previos owner ran soft copper tubing for the fuel line before and after the fuel pump (which is new) I have not tested the fuel pressure.
Btw, also the carb float is set jst a scoshe under the sight plug.
 
Sounds like a possible faulty distributor. Maybe the wrong one for the motor? Cardone is not something I'm familiar with. IH used several holly dizzy's through out the history. The one modle that is prone for failure more often is the holly gold box. There is a good write up on these stickied up top of this sub forum that describes the various distributors that IH used.

Hopefully one or a few other more tech guru's will chime in here on this. I May have over looked something.
 
The new replacement dizzy looked just like my original. I don't know about the gold box. Mine has the curved points, 1wire that goes to the coil.
 
After looking at the dizzy id thread I'm a lil confused. Mine looks just like the Holley 1510, except when I pull the cap there is no dust cover and my vac adv looks more like the prestolite, the vac line screws into the can. This is true for both the 1 pulled and the new cardone.
The prev owner was redoing the truck, the cab was repainted along with the engine being all painted the way it is painted, it looks like the engine was out of the vehicle. I don't know what was done to it. The engine is the 266e. If that makes a diff.
 
The "gold box" referred to is an "early" IH electronic ignition system. It should not be in your vintage (68) vehicle. IH started using it sometime in the early 70's (1974?).

The vacuum canisters are no longer available new. They have to be rebuilt. Ihon has them. I think. You could test yours - if it holds vacuum. Also, you could check that the vacuum line is hooked to ported vacuum. I am not familiar with the 2300, so I do not know which is the correct port on the carb. Probably a picture in the 23xx thread shows it.

As far as I am concerned, remanners (their workers) do not know the "differences" in oem distributors (especially 30, 40, 50 year old vehicles). They just put "good" pieces together.

All distributors had dust covers -- they are "gone" long before now. Most mechanics did not want to "deal" with them and just tossed them the first time the distributor was opened (points replaced).

Another thing to check -- is a fuel line "crimped" on its route from the tank to the fuel pump.

Copper fuel line:

this is not appropriate and can be dangerous. Copper line can "fatigue" and crack over time.

You should replace the copper line with steel line.

A slim possibility -- what is the I.d. Of the copper line? If it is not large enough (1/4"?; not sure the correct diameter), it could "limit" fuel flow.
 
With a timing light hookd up and I rev the engine I can see the timing advance. The 2300 only has 2 vac. Ports, 1 on the back bottom 3/8" for I assume power brakes and the other 1/8" on right side that goes to the dist.
The coppe line is 1/4". The starter went out yesterday, new will be here tomorrow, will get in on soon as I can.
 
Since previously, you had problems with the curb idle, you May want to check for a vacuum leak around the carb / intake manifold.

Imo, the vacuum advance should not be "engaged" at curb idle - if the carb is adjusted correctly.

Do not think the distributor could cause surging -- but you could check that the weight pins are not worn and that the distributor plate (piece that moves via the vacuum advance) is not loose (worn post / pin).
 
Since installing the new dist. The curb idle is remaining constant. I am going to put a new fuel fiter and replace the copper line going from fuel pump to carb with a steel 1.
The new starter came today but they ordered 1 for a 265 6cyl. Instead of a 266 , so I have to wait till tomorrow.
With the new carb the float set at just a scoshe below the sight plug, what would be a good starting point for the fuel/air screws, if I go more than 1 1/4-1 1/2 turns out I have to back the timing down closer to 2-3 deg. Btdc to get the curb idle down into the 700 rpm range.
 
If you can't turn down the idle enough while backing out the mixture screws, there is definitely a vacuum leak. Spray around the carb base and manifold with carb cleaner and note if the idle speed picks up.
 
The idle mix screws are mainly for your curb and in-gear idle. They don't have much effect once the engine has a load on it and you are into the throttle. With that, the idea is to achieve your lean best idle mixture which would be represented as a maximum vacuum reading in hg if you had a gauge connected to measure manifold vacuum. Does this surging happen only when you are at part throttle cruise, or does it also happen at wide open throttle? I wouldn't suspect that you are experiencing a part throttle lean surge condition, as that model carb should be jetted plenty fat enough out of the box to satisfy the meager demands of a 266, unless somebody pulled a real fast one on you and stuck some tiny jets in there. If you get a chance, you should get the thing up to normal temperature and go for a cruise. Maintain a steady speed of 45-50 and when you can do it safely, shut the engine off at speed and coast to the roadside. Take necessary precautions to avoid burns while randomly pulling several spark plugs one at a time. They should all have a light tan/brown residue on them if your cruise a/f ratio is perfect. If they come out nearly spotless, your ratio is too lean. Black and sooty or wet from raw fuel means the ratio is too Rich and/or the plug is fuel fouled.
 
The fuel line should be 5/16". That will be fuel 'hose' from the tank to the gas tank selector valve (if equipped) and steel to the fuel pump and from the pump to the carb. Use 5/16" brake line. Remember to add the 'in-line' fuel filters. For the high idle speed problem, it might be the replacement carb was installed a bit further foreward on the manifold than the old carb, making the throttle rod a bit short and not allowing the throttle plates to close. Try disconnecting the throttle rod from the carb to see if the idle speed can be lowered with the 'idle speed screw'. I like the throttle rod length to reach about 1/16" past the hole on the throttle connection so there is always some 'push' to close the throttle. The idle adjustment fuel screws on the side of the 350 cfm 2300 metering block are to adjust the idle fuel mix, not idle speed - but the fuel mix setting will effect the idle speed. Try 1 1/2 turns out. The 350 cfm carb May be to large for the 266 engine. The idle circuit would operate on the larger 304 engine up to about 25 - 30 mph under light throttle conditions. With the lower airflow of the 266, the idle circuit May be active to 30 - 35 mph under light throttle. The 350 cfm carb would have #61 main jets. If you have the vacuum gauge connected to manifold vacuum while driving, it will take little throttle pressure to drop the vacuum and open the power valve in the carb. The 350 carb, being for the larger displacement engines is designed to dump extra fuel 'for' those larger engines. The 266 will just get too much fuel to maintain a correct air/fuel ratio. Float setting at 'just a scoche' below the 'sight hole' should work.
Pictures??
 
I will try your suggestions tomorrow. Should there be 1 fuel filter between tank and pump and another btwn pump and carb?
Getting up to speed you feel the surge and doing 55-60 mph you feel it but around 45 it seems to pretty smooth. It accellerates fine from 45 on up it is when you try to do a steady speed it surges.
Got the new starter on and changed the 5/16" copper line from pump to carb and replaced the fuel filter, still has the same surgeing.
 
Get a 'large' fuel filter and install before the pump. Not much dirt will get through the sides of the steel fuel line. Some carbs have a small porus brass filter behind the fuel inlet. Changing the starter and fuel line will not make any difference with a surging problem. Did you use a 'tube bender' for the new fuel line? As long as the pipe didn't 'kink', you should be good.
Wonder if there are parts on the 'e' engine that May be defective and causing the surging? My 304 is the 'federal' specs with minimum emission controls. It May be necessary to open the carb to determine which main jets are in the carb.
When watching the dist advance, how much of the advance comes from the vacuum unit? What is the max total advance and if the rpms are held steady, does the advance remain steady?
The 'timing Mark' on the pully will advance beyond the scale so you will have no idea what the total advance is - so - with the motor 'off', manually rotate the crankshaft/pully clockwise so the 'Mark' on the pully is at the 10* Mark. With a bottle of white 'touchup paint', use the brush and make a small 'second Mark' at the '0' position on the pully. You now have 2 marks on the pully, 10* apart. This second Mark will make it possible to see the max advance after the base Mark has moved on past the last Mark on the scale. Just add the 10* to whatever is shown on the scale.
Is it possible the fuel has more than the 10% ethanol additive?
 
Hallaluh, I think I May have figured it out. There was a plumbing goof, that I think created an internal vacuum leak. It now purrs like a kitten will idle down. Waiting on the roads to dry to test drive.
Being my first binder and figuring out what should be and what shouldn't be, depending on what the prev. Owner had done 20yrs ago has been a chalenge.
 
A vac leak will certainly cause the issues you were having. That would also be represented on a vac gauge as a low and/or fluctuating reading. A healthy engine properly tuned at low altitude should be capable of a steady 20 or slightly higher hg reading on the vac gauge at hot curb idle.
 
It purrs like a kitten, I can lower the idle down to 400rpm. I opened the air/fuel screws to 2 turns and it died, so far it is at its best at 1 1/4 out but there is still surgeing, mainly on accelerating. To refresh it has a reman 350cfm Holley 7448 carb with a 10" air filter, new 5/16" steel line from tank to carb, new fuel filter, and a cardone reman Holley points dist.
Since m&m said ignition affects carburation, thats why I posted this issue under the ignition tech thread
 
Somethin' ain't stirrin' the kool-aid here, bubba. Your engine should have no trouble whatsoever running with the idle mix screws at 2 or even 2.5 turns out on both sides. A little Rich maybe, but should run well enough. In fact, right now your engine should be stumbling, gasping, and starving for fuel like nobody's business at only 1.25 turns out. You need to get a vacuum gauge hooked up to manifold vacuum and take a reading. Without that, you're chasing your tail, and so are those of us trying to help.
To mayben's point that you brought up...carb tuning does not effect ignition or spark timing, but ignition adjustments can effect carb tuning. That is why it is often necessary to make minor carb tweaks following changes/adjustments to the ignition system.
 
I took some readings, timing at 6 deg. Btdc, idle at 600,
intake manifold vacuum 16-17 flucates with the slight miss.

Compression:
1-132 2-135
3-132 4-143
5-135 6-135
7-130 8-145

accelerating is rough, maintaining a steady speed alot smoother.
Yesterday on one of my rides, I kept advancing the timing this morning I put a light on on it and it was up close to 20deg. Btdc

does this seem feasible that I was able to advance it that far without terribily affecting the driveability? Could it be I May be 1 tooth off on stabbing the dist? It idles so smooth except for the slight miss.

It has new points, condenser, rotor, dist. Cap, wires, plugs and wires about a year old but not alot of miles.

There is a sticky lifter you can hear ticking on occassion
(rt. Side) the slight miss at idle is constant.
 
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