Fine Tuning a stock 1972 318 w/minor modification
#1802533
04/13/15 06:07 PM
04/13/15 06:07 PM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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Playing around with my new timing light and vacuum gauge. I have a 1972 318 motor, everything is stock except the Edelbrock Performer intake, 1406 Carb, and Pertronix II ignition/flamethrower II coil. It has manual brakes, power steering, no air cond, vacuum advance carb, stock exhaust manifolds.
Was idling high and popping out exhaust. Fixed all of that.
Set: base timing to 9° @820rpm total timing to 35° @2500rpm vacuum advance hooked up, total timing sits around 49° @2500rpm
Idle set and wanders between 800 to 830rpm
Idle screws adjusted till popping stopped and a vacuum of about 21" achieved (around 2.5 turns out from seated)
No vacuum leaks detected....yet
There are a couple of things Im still trying to work out.
1st: Engine has no more backfire, runs fine and revs up fine but it shakes a little. Not bad, but it's definitely not smooth. Timing light lights up on every spark plug wire, but sure feels like there's a small misfire or maybe plugs fouling. Next step I'll pull them and check.
2nd: Is it normal for the rpm to get back to idle speed VERY slowly after reving up? When I let off the throttle, it takes the engine about 10 to 20 seconds to fully return to idle speed. The throttle linkage is not stuck it moves freely.
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1802706
04/13/15 09:44 PM
04/13/15 09:44 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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Circle Track
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(1) check plugs/wires/rotor phasing (2) not normal, check the weights
live every 24 hour block of time like it's your last day on earth
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1803154
04/14/15 12:27 PM
04/14/15 12:27 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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Circle Track
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Lincoln Nebraska
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twist the rotor into the spring tension (CW) & let loose of it & see if it snaps back sharply
live every 24 hour block of time like it's your last day on earth
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1803929
04/15/15 02:22 AM
04/15/15 02:22 AM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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Circle Track
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Lincoln Nebraska
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those are OE springs & if your rebuilt dist has the same ones be sure to toss the heavy one & sub in a mr gasket or MP light spring in place of it. On the P install do Scratchns tips: leave the green tape/dont leave ign on/cap with brass terminals/no solid core plug wires. You are using the flamethrower coil? You might weld up the slots then work with them after you finalize the initial. bottom line do NOT allow any pinging
live every 24 hour block of time like it's your last day on earth
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1803948
04/15/15 02:47 AM
04/15/15 02:47 AM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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All good on the pertronix except I dont have a brass cap. Yes using matching flamethrower II coil.
Im pretty good about not leaving ignition on, but I specifically bought the Pertronx 2 because supposedly is immune to the ignition being left on.
Edit**
On a stock street engine at whats a good RPM to have the advance fully kicked in?
Last edited by Adam71Charger; 04/15/15 03:09 AM.
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1804068
04/15/15 12:08 PM
04/15/15 12:08 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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Circle Track
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Lincoln Nebraska
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Im pretty good about not leaving ignition on, but I specifically bought the Pertronx 2 because supposedly is immune to the ignition being left on.
On a stock street engine at whats a good RPM to have the advance fully kicked in? (1) I wouldn't think the 2 or 3 are immune but check with Scratchn, he knows the ins & outs of em (2) set the initial with the vac gausge method/shorten the slots so you get 35 total & this is initial+slots with can capped) With this being a DD no hot rodding then plug the can in & likely just subbing in a weak spring for the OE thick one with the elongated end will sufffice. bottom line NO pinging wanted/allowed but for max torque/mileage you want to be pretty close to that (pinging) line. EDIT if you are going to romp on that 318 then slightly different procedure: after initial/total are set then mix/match springs so you are just under the pinging point at WOT up thru the gears on your hottest/driest day then plug in/adj the can. You definitely need a strip kit for the 1406
Last edited by RapidRobert; 04/15/15 12:51 PM. Reason: more info
live every 24 hour block of time like it's your last day on earth
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: RapidRobert]
#1804301
04/15/15 05:30 PM
04/15/15 05:30 PM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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Im pretty good about not leaving ignition on, but I specifically bought the Pertronx 2 because supposedly is immune to the ignition being left on.
On a stock street engine at whats a good RPM to have the advance fully kicked in? (1) I wouldn't think the 2 or 3 are immune but check with Scratchn, he knows the ins & outs of em (2) set the initial with the vac gausge method/shorten the slots so you get 35 total & this is initial+slots with can capped) With this being a DD no hot rodding then plug the can in & likely just subbing in a weak spring for the OE thick one with the elongated end will sufffice. bottom line NO pinging wanted/allowed but for max torque/mileage you want to be pretty close to that (pinging) line. EDIT if you are going to romp on that 318 then slightly different procedure: after initial/total are set then mix/match springs so you are just under the pinging point at WOT up thru the gears on your hottest/driest day then plug in/adj the can. You definitely need a strip kit for the 1406 ROMP INDEED
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1806724
04/19/15 07:07 AM
04/19/15 07:07 AM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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got the working vacuum canister off my old distributor installed on the new distributor. Gapped my pertronix 2 with the feeler gauge supplied in kit. Hooked my spark wires up to the new brasss cap, installed on distributer.. Carnked the motor, and it turned and turned and didnt fire. Checked the wires with timing light, none were firing. With the ignition in run, I checked the voltage to the positive side of the coil, and it was getting full battery voltage. I popped the dis cap off, couldnt see anything wrong, hooked it back up, then it fired up.
When it fired up, it started and warmed up on high idle. After a few minutes, I tapped the gas pedal, which should've brought it down to normal idle. It did not. The car stayed in high idle. I tried this a few more times... nope, it stuck on high idle. So I tried to retard initial timing, which only lowerd rpm from 1500 to 1100, but the engine started shaking so I brought it back up to till it smoothed out, but it was still idling very high. I tried to lower the idle speed screw, but it had zero effect. It's like the carb is stuck on fast idle.
IIt was running very well before I replaced the distributor, and that that is the only thing I touched. Kind of stumped on why it's stuck on the high idle.
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1806814
04/19/15 12:01 PM
04/19/15 12:01 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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It was running very well before I replaced the distributor, and that that is the only thing I touched. Do you have a (functioning) dist/ballast/coil (as needed) you can sub back in real quick to try & pin it down to the dist?
live every 24 hour block of time like it's your last day on earth
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1806991
04/19/15 04:06 PM
04/19/15 04:06 PM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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Im still stumped on my high idle. It really feels like the carb is stuck fast idle. Turning the idle set screw does nothing, even after the car is fully warmed up. My throttle cable is not stuck, it moves freely. The car ran fine, no vaccum leaks, now it acts like it has a major vacuum leak or the carb is stuck
Last edited by Adam71Charger; 04/19/15 04:07 PM.
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: dan9]
#1807709
04/20/15 01:43 PM
04/20/15 01:43 PM
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Joined: Jun 2013
Posts: 1,521 Tacoma, Washington USA
Adam71Charger
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Is the fast idle cam releasing? Bingo. No it isn't, just noticed it yesterday. That's what's causing the constant high idle. Twisted the electronic choke around and that didn't solve it. Is the choke the only thing that puts tension on that cam?
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Re: Fine Tuning a stock 1972 318 w/minor modification
[Re: Adam71Charger]
#1807734
04/20/15 02:11 PM
04/20/15 02:11 PM
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Joined: Dec 2009
Posts: 1,023 pa.
dan9
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Yes it is operated by the linkage from the choke. Usually unless it has been messed with it will just need lubed once in a while. Without the engine running you can hold the throttle wide open and inspect and lube for proper operation. It should work very freely. Once you get it feed up it sounds like you will have to reset your choke setting. A little turn can mean a lot on the choke setting.
Last edited by dan9; 04/20/15 02:15 PM.
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