351M/400 TIMING PROBLEM
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Laughing Gas
Joined: Nov 2016
Posts: 857
Likes: 63
From: Oxnard
351M/400 TIMING PROBLEM
1977 Ford F-150 351M/400, RB 435 (4x4):
Soliciting input on my timing issue. Started several projects 2020 Thanksgiving weekend. Before the projects, truck ran excellent. One of the projects was replacing the timing Gears, chain and harmonic balancer; previous timing chain set was also after market and needed changed, chain had ~ 3/4" slack, also installed Edelbrock aluminum heads, so pulled intake and distributor and added Holley Sniper 2300 EFI. New timing gears set straight up with number one cylinder on top dead center (removed passenger side value cover off to verify there wasn't any pressure on number one cylinder's value springs at TDC) , re-installed distributor exactly where I had marked it prior to removing and Rotor is pointing to number one on plug wire on the distributor cap.
Upon start-up to set base timing, the timing light reads 50 degrees BTDC. Very odd, I couldn't figure what was wrong, so I asked my mechanic friend to check it. He brought his own timing light which he verified was working on his own 1967 Camaro. His old Sun timing light also reads 50 degrees BTDC. Both I and my mechanic friend can't figure out why both timing lights are reading 50 degrees BTDC.
Request help on my timing dilemma. Thank you
Soliciting input on my timing issue. Started several projects 2020 Thanksgiving weekend. Before the projects, truck ran excellent. One of the projects was replacing the timing Gears, chain and harmonic balancer; previous timing chain set was also after market and needed changed, chain had ~ 3/4" slack, also installed Edelbrock aluminum heads, so pulled intake and distributor and added Holley Sniper 2300 EFI. New timing gears set straight up with number one cylinder on top dead center (removed passenger side value cover off to verify there wasn't any pressure on number one cylinder's value springs at TDC) , re-installed distributor exactly where I had marked it prior to removing and Rotor is pointing to number one on plug wire on the distributor cap.
Upon start-up to set base timing, the timing light reads 50 degrees BTDC. Very odd, I couldn't figure what was wrong, so I asked my mechanic friend to check it. He brought his own timing light which he verified was working on his own 1967 Camaro. His old Sun timing light also reads 50 degrees BTDC. Both I and my mechanic friend can't figure out why both timing lights are reading 50 degrees BTDC.
Request help on my timing dilemma. Thank you
Lead Driver
Joined: Nov 2006
Posts: 5,217
Likes: 506
From: Pa.
Hey EQCMCAT, IF you've changed the Timing set and set it to be straight up and still have the original distributor and haven't recalibrated it then that's part of the problem. I've not done an EFI conversion yet so excuse my ignorance in that regard.
More Turbo
Joined: Jan 2021
Posts: 603
Likes: 172
From: Flo-rida
Is vac hooked up to dizzy, that could account for some of it. But not 50. How does it start? Id think hard to crank that much before tdc. Are sure new balancer has same degree marks as the one you took off?
More Turbo
Joined: Jan 2021
Posts: 603
Likes: 172
From: Flo-rida
I think there are 2 different balancers for the 400 depending on pointer location left or right side. Id verify tdc with Mark on balancer. If not make a new mark. 2 pieces of tape different color than balancer placed side by side with a little gap between them makes a clear line to mark 0
Thread Starter
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Laughing Gas
Joined: Nov 2016
Posts: 857
Likes: 63
From: Oxnard
RedRoad,
I'm unaware of how to recalibrate the distributor. If you don't mind, please explain the process. Thank you
77 HOS,
I plugged the vacuum with a Gold Tee. It's difficult to start, sound like its really laboring, similar to a low battery while cranking. Because I was doubting myself, last Sunday I removed alternator, power steering pump, radiator, shroud, harmonic balancer, fan, water pump and front cover to re-check where the timing gears were IRT to number one cylinder on TDC, they are straight up (crank gear at 1200 clock and cam gear at 6:00 clock). New gaskets again, but used the original harmonic balancer to rule out an incorrectly marked new balancer. Why I'm stumped.
I'm unaware of how to recalibrate the distributor. If you don't mind, please explain the process. Thank you
77 HOS,
I plugged the vacuum with a Gold Tee. It's difficult to start, sound like its really laboring, similar to a low battery while cranking. Because I was doubting myself, last Sunday I removed alternator, power steering pump, radiator, shroud, harmonic balancer, fan, water pump and front cover to re-check where the timing gears were IRT to number one cylinder on TDC, they are straight up (crank gear at 1200 clock and cam gear at 6:00 clock). New gaskets again, but used the original harmonic balancer to rule out an incorrectly marked new balancer. Why I'm stumped.
Lead Driver
Joined: Nov 2006
Posts: 5,217
Likes: 506
From: Pa.
RedRoad,
I'm unaware of how to recalibrate the distributor. If you don't mind, please explain the process. Thank you
77 HOS,
I plugged the vacuum with a Gold Tee. It's difficult to start, sound like its really laboring, similar to a low battery while cranking. Because I was doubting myself, last Sunday I removed alternator, power steering pump, radiator, shroud, harmonic balancer, fan, water pump and front cover to re-check where the timing gears were IRT to number one cylinder on TDC, they are straight up (crank gear at 1200 clock and cam gear at 6:00 clock). New gaskets again, but used the original harmonic balancer to rule out an incorrectly marked new balancer. Why I'm stumped.
I'm unaware of how to recalibrate the distributor. If you don't mind, please explain the process. Thank you
77 HOS,
I plugged the vacuum with a Gold Tee. It's difficult to start, sound like its really laboring, similar to a low battery while cranking. Because I was doubting myself, last Sunday I removed alternator, power steering pump, radiator, shroud, harmonic balancer, fan, water pump and front cover to re-check where the timing gears were IRT to number one cylinder on TDC, they are straight up (crank gear at 1200 clock and cam gear at 6:00 clock). New gaskets again, but used the original harmonic balancer to rule out an incorrectly marked new balancer. Why I'm stumped.
More Turbo
Joined: Jan 2021
Posts: 603
Likes: 172
From: Flo-rida
The laboring on start is due to too much advance. Plug firing and pushing piston back down against the starter so it is too far advanced. Move all the plug wires one spot to the left counter clockwise on the cap. Each one is approx 45* apart. I think you maybe got off by one spot.
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Thread Starter
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Laughing Gas
Joined: Nov 2016
Posts: 857
Likes: 63
From: Oxnard
RedRoad,
Thank you for providing the Ford Dura--spark Distributor Recurve Instructions link with steps one through 7, very insightful.
BearTracks,
Timing Light lead was hooked up to Passenger Side, Front Plug Wire, number one cylinder.
Printed out the Ford Dura--spark Distributor Recurve Instructions and showed them to my friend, the Mechanic. He's actually our Maintenance Supervisor at work and he said, we'll go through the steps next week after work. The information now has him and myself thinking, a good thing. In the interim, have plenty to do, have to re-install the Fan, Radiator, Shroud, Alternator, Power Steering Pump, ref-fill with coolant and the motor oil I drained into a clean Home Depot bucket and covered. Plus have some yard work to do, charge vehicle batteries, fix the front passenger turn signal on the Tacoma. Will close this Thread and update the title once timing dilemma is solved with what was required to fix the problem.
Thank you for providing the Ford Dura--spark Distributor Recurve Instructions link with steps one through 7, very insightful.
BearTracks,
Timing Light lead was hooked up to Passenger Side, Front Plug Wire, number one cylinder.
Printed out the Ford Dura--spark Distributor Recurve Instructions and showed them to my friend, the Mechanic. He's actually our Maintenance Supervisor at work and he said, we'll go through the steps next week after work. The information now has him and myself thinking, a good thing. In the interim, have plenty to do, have to re-install the Fan, Radiator, Shroud, Alternator, Power Steering Pump, ref-fill with coolant and the motor oil I drained into a clean Home Depot bucket and covered. Plus have some yard work to do, charge vehicle batteries, fix the front passenger turn signal on the Tacoma. Will close this Thread and update the title once timing dilemma is solved with what was required to fix the problem.
Thread Starter
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Laughing Gas
Joined: Nov 2016
Posts: 857
Likes: 63
From: Oxnard
77 HOS,
Thanks for the tip and I will re-check my spark plug wires routing. The Illustration Red Road provided in Post 9 above, I printed that ~ two or three years from a former Forum post and used it a few times already and have since filed in my "1977 Ford F-150 How To" large three ring binder.
Thanks for the tip and I will re-check my spark plug wires routing. The Illustration Red Road provided in Post 9 above, I printed that ~ two or three years from a former Forum post and used it a few times already and have since filed in my "1977 Ford F-150 How To" large three ring binder.
Thread Starter
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Laughing Gas
Joined: Nov 2016
Posts: 857
Likes: 63
From: Oxnard
(Resolved)
Former timing issue resolved. Used a Rock Auto re-manufactured Motorcraft distributor and that solved my former jumping to ~ 50 degrees BTC timing issue.
Moreover, after looking closely inside the Rock Auto re-manufactured distributor and comparing it to my original distributor, the base plate on my distributor was approx. ~ 1" turned to the left.
Know the post is over two weeks old, but wanted to close it out. Truck seems to be running extremely well on the five mile round trip to my local exhaust shop, getting the exhaust system re-welded. Will take a few more pictures of the installed Holley Sniper 2300 EFI and do a thread on my EFI swap. This Saturday morning plan to give the 77 F-150 a good cleaning, then haul kitchen chairs to my neighbor's re-upholstery shop. In the two weeks since 15 July 2021 post, we took a week off (planned) trout fishing trip whereas my youngest son and grandson joined us mid-week. Grandson caught his first trout and has asked "when are we going back". Life doesn't get any better than that.
Moreover, after looking closely inside the Rock Auto re-manufactured distributor and comparing it to my original distributor, the base plate on my distributor was approx. ~ 1" turned to the left.
Know the post is over two weeks old, but wanted to close it out. Truck seems to be running extremely well on the five mile round trip to my local exhaust shop, getting the exhaust system re-welded. Will take a few more pictures of the installed Holley Sniper 2300 EFI and do a thread on my EFI swap. This Saturday morning plan to give the 77 F-150 a good cleaning, then haul kitchen chairs to my neighbor's re-upholstery shop. In the two weeks since 15 July 2021 post, we took a week off (planned) trout fishing trip whereas my youngest son and grandson joined us mid-week. Grandson caught his first trout and has asked "when are we going back". Life doesn't get any better than that.
Was beginning to think we needed to send the scouts out. 
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