1963 170 hesitation issues

[bubba22349]

Yes it is not only possible to set them with the engine running but this is usually my perfered method. Most people don't do it that way though because it can be messy with their freshly painted engine. Also because of the location of the adjuster screw and depending on the idle RPM it's not as easy to do as say with a SBF or Brand X Chxxxy. Good luck

 

[Creechn32]

UPDATE: I went back and adjusted the valves properly for the hydraulic lifters. I did this while the engine was running, loosening the adjusters until there was a tap and tightening just a little at a time until the tap was gone, then 1/4 turn and wait a few seconds and a 1/4 turn more for a total of 1/2 a turn. I did this with an engine already at operating temperature. I went back and checked the gap on all my plugs, turned out the round metal spark plug gapper I was using (the metal ramp style you get from autozone) was off. I widened the gap checking with feeler gauges that I have. Will use these from now on when gapping plugs. Checked my dwell angle again and it is sitting at 37*. Hooked the vacuum gauge up, disconnected vacuum from the distributor and set initial timing to vacuum. Adjusted idle mixture screw on carburetor. The timing is still sitting at close to 30* initial advance and doesn't advance much past that when accelerating. Just what the engine likes I suppose. All this has done away with the majority of hesitation. I'm still curious about the initial timing setting however. Even though the engine seems to be working better I still think I should be closer to stock settings. I took the car out for about a ten minute drive with no issues really. In the past couple weeks I have verified that the TDC marks do line up on the dampener when #1 piston is brought up. Maybe someone might have a theory????

 

[frozenrabbit]

Maybe a slipped damper, and not 100% TDC?

By the stock timing mark, I'm around 30-ish advanced at idle on my '63 170, filed a corrected timing mark when I replaced the timing chain and had the head off for a valve job.

Rubber packing looks fine on mine, but has definitely slipped, will replace it someday.

 

[62Cometman]

I second rabbits thought process but also just cause im curious how hard or easy does the car start? also does it run hot or cold? when you get into the upper rpm range does it still perform well? and what do the plugs look like? "overly" advanced timing can cause issues in any one of these area that could help identify if its actually 30 degrees or maybe if something else is giving a false positive

 

[Creechn32]

I second rabbits thought process but also just cause im curious how hard or easy does the car start? also does it run hot or cold? when you get into the upper rpm range does it still perform well? and what do the plugs look like? "overly" advanced timing can cause issues in any one of these area that could help identify if its actually 30 degrees or maybe if something else is giving a false positive

Engine starts easily, fires right up, shuts right down, starts right back up. Engine temp stays in the normal range, I bought a set of triple gauges (volt, temp, oil press) to install in the car to have a better idea of how it's really running. Have not installed them yet, maybe this weekend. Engine runs nice and strong in the upper RPM's. Never had a problem when getting on the gas, just the hesitation from a stop. The hesitation is pretty much fixed now other than a slight skip when leaving from a stop. Other than that I didn't have any hesitation on my earlier drive.

 

[StarDiero75]

I dont have much experience with the autolite 1100 as I thought it was a crap carb and gave me nothing but headache, but i had a similar issue with a mid 50's Holley 1904 on my 200. It would hesitate when i hit the gas, almost all the time. Found out when i rebuilt it, there are 2 different length accelerator pumps, i got the short one when i needed the long one. I didn't know this till one day i watched a video for funnon rebuilding it and the guy mentioned it. I replaced it and it went away.

Is there something similar that it could be in the 1100? That would make sense if so.

Good luck,
Ryan

 

[Creechn32]

I dont have much experience with the autolite 1100 as I thought it was a crap carb and gave me nothing but headache, but i had a similar issue with a mid 50's Holley 1904 on my 200. It would hesitate when i hit the gas, almost all the time. Found out when i rebuilt it, there are 2 different length accelerator pumps, i got the short one when i needed the long one. I didn't know this till one day i watched a video for funnon rebuilding it and the guy mentioned it. I replaced it and it went away.

Is there something similar that it could be in the 1100? That would make sense if so.

Good luck,
Ryan

I know I can and have adjusted the accelerator pump rod to 3/16" with a drill bit. Method I learned online watching Mikes Carbs rebuild videos. This is the first I'm hearing of different accelerator pumps for the 1100....

 

[StarDiero75]

I dont have much experience with the autolite 1100 as I thought it was a crap carb and gave me nothing but headache, but i had a similar issue with a mid 50's Holley 1904 on my 200. It would hesitate when i hit the gas, almost all the time. Found out when i rebuilt it, there are 2 different length accelerator pumps, i got the short one when i needed the long one. I didn't know this till one day i watched a video for funnon rebuilding it and the guy mentioned it. I replaced it and it went away.

Is there something similar that it could be in the 1100? That would make sense if so.

Good luck,
Ryan

I know I can and have adjusted the accelerator pump rod to 3/16" with a drill bit. Method I learned online watching Mikes Carbs rebuild videos. This is the first I'm hearing of different accelerator pumps for the 1100....

The accelerator pump I'm talking about was off a Holley 1904, yours will be different being a different carb. I was just referencing it so maybe there was something similar in the 1100. I have never messed with an 1100 so i don't know if thats the case with it

 

[Creechn32]

Seems that you referencing the 1904 slipped my attention. I have thought about finding another acceptable 1100 to rebuild, or an 1101 as that might give me a slight bump in power. This 1100 that I'm running looks like it was purchased by the previous owner so they wouldn't have to rebuild the original. I've never been impressed with generic carbs from the auto parts store. I did rebuild it but it was dark and cold when I did it, could've missed something but the carb idles smoothly and accelerates nicely....

 

[StarDiero75]

Seems that you referencing the 1904 slipped my attention. I have thought about finding another acceptable 1100 to rebuild, or an 1101 as that might give me a slight bump in power. This 1100 that I'm running looks like it was purchased by the previous owner so they wouldn't have to rebuild the original. I've never been impressed with generic carbs from the auto parts store. I did rebuild it but it was dark and cold when I did it, could've missed something but the carb idles smoothly and accelerates nicely....

It just hesitates.... Try to get another carb cheap and see what that one does. I will never buy a rebuilt carb from an auto parts store or anywhere. I always buy cores and do it myself. I've done 3 and only had 1, which had a broken mixture screw, which was bad. I bought a rebuilt one once, and that was a terrible nightmare, plus getting ahold of the company that sold it so i could get a refund, OH MY! If you still have the LOM dizzy you'll be limited, if not, you can look at getting something different like a weber or even a Holley 1904.

They make those in SCV version, you might look into those. I really like those carbs, very simple and easy to work on. I'm trying to get 1 more so i can do tri power in the future. And 1 more glass bowl too.

 

[bubba22349]

UPDATE: I went back and adjusted the valves properly for the hydraulic lifters. I did this while the engine was running, loosening the adjusters until there was a tap and tightening just a little at a time until the tap was gone, then 1/4 turn and wait a few seconds and a 1/4 turn more for a total of 1/2 a turn. I did this with an engine already at operating temperature. I went back and checked the gap on all my plugs, turned out the round metal spark plug gapper I was using (the metal ramp style you get from autozone) was off. I widened the gap checking with feeler gauges that I have. Will use these from now on when gapping plugs. Checked my dwell angle again and it is sitting at 37*. Hooked the vacuum gauge up, disconnected vacuum from the distributor and set initial timing to vacuum. Adjusted idle mixture screw on carburetor. The timing is still sitting at close to 30* initial advance and doesn't advance much past that when accelerating. Just what the engine likes I suppose. All this has done away with the majority of hesitation. I'm still curious about the initial timing setting however. Even though the engine seems to be working better I still think I should be closer to stock settings. I took the car out for about a ten minute drive with no issues really. In the past couple weeks I have verified that the TDC marks do line up on the dampener when #1 piston is brought up. Maybe someone might have a theory????

congrats on the progress you have made. Yes you are correct that the engine should be closer to the stock settings. So can you get the engine to run with setting the base timing to 10 to 14 degrees? What is your idle RPM? The reason that it won't advance much after you have set base timing close to 30 degrees is that there isn't much more left to advance in the Distribitor, (maybe only 4 to 6 degrees). There isn't any different lenght of accelerator pumps for the Autolite carb's, but you should still be able to fine tune the accelerator pump shot a little more to remove that stumble. A stumble or bog can be caused either by too much or too little of a accelerator pump shot and or its timing being wrong starting to soon or coming in too late. However you will first need to get the ignistion system and timing dialed in. Good luck

 

[Creechn32]

Yes, the engine will run when timed near 12-16*. It just runs very poorly, vacuum goes way down and the engine has a hard time revving without a load in park. My idle is close to spec, it's been changed a number of times. Every time I dial something in it increases and I'm left adjusting it back down. Engine is running quite well right now even with initial advance way out there. I'm wondering if perhaps I might need to adjust the accelerator pump for more of a shot at takeoff. Could always adjust it back if it has the opposite effect. I installed the triple gauges today after stripping the fitting for the oil pressure gauge and making a trip to the parts store. It's alright, I have a nice copper line instead of a plastic one now. Looks like it belongs compared to shear plastic one. I say all that to say that the temperature is running right where it should. Could take it for a longer drive just to make sure but it seems to be doing well. Still might remove the timing cover in the future just to inspect everything a little closer. Would be easier to check for slop and proper installation.....

 

[bubba22349]

Yeah that is strange, Ok have you checked for vacuum leaks at the base of the carb? Does the carb's throttle shaft show any up and down slop or looseness. When the vacuum gauge is installed do you have everthing hooked up as the car would be driven? Dose the vacuum gage read rock steady? Anyway you have now tuned around most of your issues even though there is still some underlying problem that is the cause. Atleast you are getting close to be able to use the car reliably. Yes by all means try adjusting that accelerator pump for more of a shot it's very likely to help in the near term. Good luck

 

[Creechn32]

Yeah that is strange, Ok have you checked for vacuum leaks at the base of the carb? Does the carb's throttle shaft show any up and down slop or looseness. When the vacuum gauge is installed do you have everthing hooked up as the car would be driven? Dose the vacuum gage read rock steady? Anyway you have now tuned around most of your issues even though there is still some underlying problem that is the cause. Atleast you are getting close to be able to use the car reliably. Yes by all means try adjusting that accelerator pump for more of a shot it's very likely to help in the near term. Good luck

I have checked for vacuum leaks. Carb plate and carb are both nice and tight. Vacuum gauge reads rock steady with everything hooked up.

 

[bubba22349]

Ok then it looks like you have covered everthing external then and have circled around back to possible internal causes such as the cam degreeing and or timing chain set. Its great if your now able to drive it and enjoy the car for awhile until your ready to dive into anything else. Good luck