Hard to start in the morning, running rich and slooooww...

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puna_trav

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I've got a '68 Valiant moredoor with a 225, fresh remanned Holley 1920 with a manual choke conversion, and a Pertronix electronic pickup on it.

This thing has always been slow. With the old carb, I could barely scratch 60mph on flat ground, and any adjustments I made seemed to have no effect. That's what lead to the pertronix and new carb.

I've done timing, valve adjustment, and have used 3 different jets (56, 54, and now I'm running a 52) I'm running Autolite 66's except for plugs 1&6 which are constantly black-soot carbon fouled so I switched them to 65's which seem to do better.

I've bypassed the bulkhead connectors in the problem areas, replaced the ignition switch (which was making it near impossible to start for a while), replaced the voltage regulator with a solid state, replaced the coil, starter relay and all the normal wear and tear bits on the ignition system.

Here's the problem:
For a while it would start right up with this same setup and no choke. One or two times cranking, tops. Now it takes close to 10 minutes of cranking to start, choked or not. Starter fluid seems to make it harder to start.
Once it starts, there's a big puff of black smoke and it runs rough until it gets up to temp a bit.
Once up to temp, it tries to stall coming off a stop no matter what I do to the A/F screw on the carb. I see slight changes as I fiddle with it, but minimal. It'll miss a few times, nearly die, then surge forward.
Once moving it seems fine, but really limp-wristed. Foot on the floor with a slight incline, I'm lucky to hit 50mph within a half mile. On flat ground it'll accelerate slightly better and carry on to just over 70 if I floor it. The first two gears feel ok-ish, but it feels like it simply doesn't have the power to pull in third. Considering I have smaller-than-stock tires out back, it should have no problem pushing the car along.
Plugs 1&6 still carbon foul heavily, and all plugs look a pretty rich. It'll start in the first half crank once that initial startup happens in the morning.

Any clues for me?
 
what is your timing set at? those reman carbs are notorious for being poorly done.

your 225 should be able to spin the tires & move that valiant to 70 mph no problem.

if you were in Wichita I could help more- that would be quite a feat--

the petronix does change the timing a bit you -need to check it again.

I'm leaning to carb issues-- I know you do not want to hear that, unless your motor is total shot. Lawrence
 
Rich condition for sure. Pull that carb apart. check float level, needle and seat condition jetting etc. Also verify timing... if that's off, nothing will help much.
 
Awesome! Exactly the kinds of clues I was looking for. I haven't shot the timing since I first installed the Pertronix, and I'm pretty sure I've got it at the stock setting of 5 degrees advance. Also haven't done much more than swap jets in the carb since I got it. I'll take a look at the float and needle seating tonight.
Thanks again guys, you're the best!
 
you should be running a 57 jet for starters

sounds like your float is to high and is sucking fuel thru the booster, at idle look down the throat and see if you see fuel coming from the little "H" or what we call a wagon wheel. if there is your float is to high or sunk.

Next on the timing, you want to get it up to about 12-16* initial, 30 total by 2500 rpm while having the vacuum can set to start moving at 10" of vacuum.

More than likely the stall is a rich condition but there is a chance its lean due to your low speed bleed being way to big (bigger= leaner=stumble) while looking down the throat you will see three holes (4 if you count the one for the accel pump squirter(hitting the throttle will show you that one)). The one farthest from the head, the middle one (high speed bleed) and then the one closest to the head (low speed). If its any bigger than .035" you'll have a lean stumble. Now sometimes near the fuel inlet (up and to the throttle linkage side) there will be a little screw, adjusting it will be the same as adjusting the size, i recall 4 turns out on it is about right and about 1.5-2 turns on the idle mix screw.

i can get pics if you like.
 
some pics

You can see i soldered the low speed bleed and then drilled it to .025" as i didn't have a .035" bit. I tried a .040" bit and still bogged so a good range is .025-.035 depending on factors of your location.

you get a better idea of the "H" booster in the throat of the carb

in the bright pic you can see the divit and little hole, thats the accel pump squirter hole, above it with solder on it is the low speed.

last pic is where the screw will be IF it has one, not all did, and most were covered by lead but its obvious.

once it start running better change the plugs for the NGK 3459's and remove the washer. I use 66's in my race slant so i think they are to cold for you, but never remember if the 65 or 67 is hotter...
 

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So did some fiddlin' after work. Checked the 'wagon wheel' and no sign of fuel. Then took a look at timing. Sure enough, 5* advance. Bumped it up to 13ish degrees and suddenly its idling smooth and the A/F screw actually has some effect. Dialed it in a bit and took it for a ride...

I actually got this bastard sideways coming out of my street.

Came home and the plugs are reading almost normal, but are all a bit fouled from before. I'll try to track down a set of NGKs next (my) weekend.

I love you guys! Thank you!:burnout:
 
If your parts store can't find the NGK by the number, tell them you need plugs for a 96 jeep cherokee with a 4.0L

For some reason when I bought mine from autozoo, they typed in the number and found no matches, when I gave them the jeep it came up with the part number and all lol!
 
One thing to check with your Pertronix is the "rotor phasing". Best to install an old distributor cap with a hole cut out to view the rotor tip with a timing light. You should see the tip near the post, varying only +/-15 deg due to vacuum advance. If not, it could be sparking to the wrong post at times. I recall reading that this is sometimes a problem with Pertronix. The Holley XR700 manual (latest) explains, which you can find in a web search, plus several posts here. Also, SlantSixDan found many poorly manufactured slant six caps out there, which you can read about here or on slantsix.org.
 
BillGrissom said:
One thing to check with your Pertronix is the "rotor phasing". Best to install an old distributor cap with a hole cut out to view the rotor tip with a timing light. You should see the tip near the post, varying only +/-15 deg due to vacuum advance. If not, it could be sparking to the wrong post at times. I recall reading that this is sometimes a problem with Pertronix. The Holley XR700 manual (latest) explains, which you can find in a web search, plus several posts here. Also, SlantSixDan found many poorly manufactured slant six caps out there, which you can read about here or on slantsix.org.
Click to expand...

those caps are the brass contact ones made/sold at napa. The Standard "Blue Streak" CH-410 (CH-410X old number) is a brass cap with no cast issues
 
Drove it all day today, and for the most part it runs well. I noticed the #6 plug is still getting carbon fouled, but the other plugs are a bit lean with a 52 jet. I put in a 56, but haven't had a chance to do a plug read again since. Seems to run better, though.
Currently I have a Standard blue streak cap and rotor on the distributor, and they are relatively new.
I'm still noticing a slight miss at idle, or when the motor is being held at a constant speed at low (>3000rpm) rev. I am chocking it up to the fouled #6 until I replace the plugs.

Thanks again for all your advice, driving the Valiant today was like being in a different car!
 
puna_trav said:
Drove it all day today, and for the most part it runs well. I noticed the #6 plug is still getting carbon fouled, but the other plugs are a bit lean with a 52 jet. I put in a 56, but haven't had a chance to do a plug read again since. Seems to run better, though.
Currently I have a Standard blue streak cap and rotor on the distributor, and they are relatively new.
I'm still noticing a slight miss at idle, or when the motor is being held at a constant speed at low (>3000rpm) rev. I am chocking it up to the fouled #6 until I replace the plugs.

Thanks again for all your advice, driving the Valiant today was like being in a different car!
Click to expand...

with the 56 you'll probably see a little hesitation at cruise and be in the power valve more than needed.

On lean #6 do you have power brakes? you should check the fitting, 3/8" line, and booster to make sure you dont have a leak. that would lean out just number six.

On the slight miss its a slant thing, i know of only one car that has gotten rid of it with a homebrew water injection. But somethings that will cause it are to lean or to fat, holes/cracks/leaks in the exhaust, ignition issues as well. i'll get i vid of my swinger and you can tell me if its the same thing.
 
Damn Kid, that's the best 1920 rundown I have ever seen. Good job!
 
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