Slant 6 dies.

-
68383GTS

68383GTS

Well-Known Member
Joined
Nov 15, 2007
Messages
7,498
Reaction score
950
Location
East Peoria,IL
My slanty started dieing at stop lights or down shifting and then slowing for a stop. I idled it up this helped some. But then when I bolt the air cleaner down it runs rough and dies. Take the air cleaner off and it runs good. So I am thinking I need to adjust the air mixture screw? Should I screw it all the way in and then back it out three 1/4 turns and go from there? I haven't touched a slanty carb in 25 years...lol
 
Look in your favtory service manual there is a procedure.

25 years on a carb is a LONG time. Might be time for a rebuild.
 
If your motor dies when you install your air cleaner- there is something wrong with your air cleaner! Or- the A/C stud is pulling and warping something.
 
68383GTS said:
My slanty started dieing at stop lights or down shifting and then slowing for a stop. I idled it up this helped some. But then when I bolt the air cleaner down it runs rough and dies. Take the air cleaner off and it runs good. So I am thinking I need to adjust the air mixture screw? Should I screw it all the way in and then back it out three 1/4 turns and go from there? I haven't touched a slanty carb in 25 years...lol
Click to expand...
Try cleaning the air filter element or replacing it.
 
IF IT'S NEW ENOUGH TO HAVE HEATED AIR INTAKE, A CRACKED EXHAUST MANIFIOLD CAN PLUG THE AIR FILTER PRETTY QUICK.
 
Needle & seat in the carb wears over time & miles, raises fuel level & makes the mixture richer. Some air cleaners can cause a choking effect, which richens the mixture. Removing the AC leans it out.
I would get a rebuild kit for the carb, or at the very least, check the float adjustment.
 
Going to 318 out of frustration because of the die out? I rewired mine to get rid of the lean burn, largely because the original wiring was by far THE worst hack job I have ever seen on any other one vehicle in my life. It was so bad that I didn't think I could salvage the original harness, and am extremely surprised there was even a truck available for me to buy, I have no idea how this truck didn't burn to the ground before I ever found it sitting in the POs yard.
My truck is an 85, I went to the local junkyard and got an engine compartment wiring harness that happened to come from an 84 1 ton that had a 360. So I started with a harness lacking lean burn to begin with.
I untaped it all and checked the donor harness for chafed wiring and hard insulation from sheer age/ replaced a few sections. And extended a few leads to accommodate the /6.
While I was at it I incorporated an underhood fuse box from a square body ranger (90-93ish) and eliminated every fusible link in the original harness. I ran every circuit that used to be fusible linked to an appropriate maxi fuse. It wasn't hard to line up what gauge wire from the truck went where on the fuse box. I ran same gauge the same gauge on the fuse box and I have ea couple of spots left for future accessories.

I think all but 1 of the original fusible links were BBQ'd, and 2were also fried on the original harness
I also ran a redundant 10 ga to the hot lead on the alternator and thru the fuse box, the original setup had all the current from the alternator going thru a spade terminal in a connector by the firewall and regulator. Which I also left as stock.
I then hand drew a diagram showing what original fusible linked circuit now goes to what hole in the fuse box. My 85 D150 is staying a slant, u have a 74 225 on the stand almost ready to go in, upgraded with more power.
 
Oh and 1 other thing
Every connection I made is crimped, soldered and heat shrinked. I'll tell some of the Gorey details of the POs hacks another time.
 
Got to have the car in gear with the brakes holding it basically under load to tune the idle mixture screws correctly and that's once you have the idle speed adjusted to where it needs to be. Slants are notorious for eating the distributor gear so pull the cap and check to see if your rotor doesn't turn a lot back and forth
 
volaredon said:
Going to 318 out of frustration because of the die out? I rewired mine to get rid of the lean burn, largely because the original wiring was by far THE worst hack job I have ever seen on any other one vehicle in my life. It was so bad that I didn't think I could salvage the original harness, and am extremely surprised there was even a truck available for me to buy, I have no idea how this truck didn't burn to the ground before I ever found it sitting in the POs yard.
My truck is an 85, I went to the local junkyard and got an engine compartment wiring harness that happened to come from an 84 1 ton that had a 360. So I started with a harness lacking lean burn to begin with.
I untaped it all and checked the donor harness for chafed wiring and hard insulation from sheer age/ replaced a few sections. And extended a few leads to accommodate the /6.
While I was at it I incorporated an underhood fuse box from a square body ranger (90-93ish) and eliminated every fusible link in the original harness. I ran every circuit that used to be fusible linked to an appropriate maxi fuse. It wasn't hard to line up what gauge wire from the truck went where on the fuse box. I ran same gauge the same gauge on the fuse box and I have ea couple of spots left for future accessories.

I think all but 1 of the original fusible links were BBQ'd, and 2were also fried on the original harness
I also ran a redundant 10 ga to the hot lead on the alternator and thru the fuse box, the original setup had all the current from the alternator going thru a spade terminal in a connector by the firewall and regulator. Which I also left as stock.
I then hand drew a diagram showing what original fusible linked circuit now goes to what hole in the fuse box. My 85 D150 is staying a slant, u have a 74 225 on the stand almost ready to go in, upgraded with more power.
Click to expand...
No going to a 318 because I just have a fresh 318 sitting in my garage.
 
If you have the Holley 1920, I went thru 3 bad rebuilt ones before a 4th one finally made the engine idle like a kitten. That was over 20 years. The final straw was when a newly rebuilt longblock wouldn't idle well, so figured it had to be the carburetor, despite changing it twice already. They have a sealed metering block which clogs and rebuilders don't get in there or even test the rebuild. I agree that installing the air filter shouldn't affect the engine. Figure that out first.
 
Worth a try:

Pull the air cleaner off, rev the motor up to about 2k RPM. Then open the throttle all the way, and use your hand to choke out the carburetor and stall the engine (still holding the throttle wide open until it dies).
This will flood the engine, but just put the pedal to the floor when you crank it back up to clear out the excess gas.

What this does, is, if theres any small crud thats gunking up the internal works of the carburetor, the few moments of intense vacuum (wide open throttle but closed off to air) will suck the junk out the vents/venturis/jets. This has helped me with a few rough carbs in the past, and, may take a couple of tries.
 
Your dying while coming to a stop could be bad points. They go bad after awhile.
Now you've gone and messed with the carb and it's trying to accommodate for that too.
 
^^^^ This. Very good point. Pardon the pun, points gap closes up due to rubbing block wear. High[er] idle rpm gives just enough centri force to open points, keep engine running above idle.
 
You must log in or register to reply here.
-

Back
Top