300 i6 timing issues
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Mountain Pass
Joined: Jan 2021
Posts: 167
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From: North Of Dallas
300 i6 timing issues
so I'm having a heck of a time with my 1981 f-150 4.9's timing. so when I get it to where it should be the motor when killed won't turn back over easily. I've run timing gun's vacuum gauge and just setting in on the 10-degree mark it all is the same
More Turbo
Joined: Oct 2020
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From: Houston
How good is your battery? What is the voltage prior to cranking? As a wise man once said, "Charge that poor battery first!"
With each cylinder displacing 50 ci, cranking through the first compression is like turning a 400 v8. I recently replaced a weakish battery, and put it in a Fairlane 289 I'm working on. It spins that small block like no tomorrow, but each cylinder is only 35 ci.
With each cylinder displacing 50 ci, cranking through the first compression is like turning a 400 v8. I recently replaced a weakish battery, and put it in a Fairlane 289 I'm working on. It spins that small block like no tomorrow, but each cylinder is only 35 ci.
Lead Driver
Joined: Nov 2013
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I noticed a minor typo in your reply. It should read “wise man who smells nice”.
But definitely follow the advice of that wise, nice-smelling and amazingly modest man and charge your poor battery first. Don’t waste your time with a trickle charger. It won’t cut it. You’ll want an automatic charger with at least a ten amp output. If you don’t have access to one, take the battery to any parts store and they will charge it for free. Please don’t skip this important step as you must have a fully charged battery before beginning any electrical troubleshooting.
While waiting for the battery to charge, check the accuracy of your timing marks. It’s possible for the outer sleeve on the pulley to slip and throw the marks way off. Bring #1 piston to TDC. Make sure the timing marks agree.
After those two prerequisite steps, pour some coffee and have a read:
https://www.ford-trucks.com/forums/1...w-starter.html
Ten minutes with a voltmeter, three quick test setups, and you will have a pinpoint answer why your starter is dragging. The test also rules out any potential problems from too much timing advance overwhelming the starter system.
But definitely follow the advice of that wise, nice-smelling and amazingly modest man and charge your poor battery first. Don’t waste your time with a trickle charger. It won’t cut it. You’ll want an automatic charger with at least a ten amp output. If you don’t have access to one, take the battery to any parts store and they will charge it for free. Please don’t skip this important step as you must have a fully charged battery before beginning any electrical troubleshooting.
While waiting for the battery to charge, check the accuracy of your timing marks. It’s possible for the outer sleeve on the pulley to slip and throw the marks way off. Bring #1 piston to TDC. Make sure the timing marks agree.
After those two prerequisite steps, pour some coffee and have a read:
https://www.ford-trucks.com/forums/1...w-starter.html
Ten minutes with a voltmeter, three quick test setups, and you will have a pinpoint answer why your starter is dragging. The test also rules out any potential problems from too much timing advance overwhelming the starter system.
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Mountain Pass
Joined: Jan 2021
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From: North Of Dallas
Lead Driver
Joined: Nov 2013
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With your starter system, one very likely possibility is a bad cable. Note I didn’t say replace all your cables. Test first and determine if they are bad. Then repair or replace as needed.
Don’t forget to charge your new battery. They typically are not fully charged at the time of sale.
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From: Virginia
How does it crank over when it's cold? If it drags when the engine is cold, I don't think it's s timing problem. You have turned the timing back and it cranks better?
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Mountain Pass
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So it cranks good when cold and when you turn the distributor to retard the timing but when hot or timing set to 10° BTDC it's hard to crank?
Battery cables could be the issue and with the test Karl wants you to do would tell you really quick.
Now I also wonder could the Advance weights get stuck advance when hot? Might try tapping the distributor with a hammer and see if that changes anything.
Dave ----
Battery cables could be the issue and with the test Karl wants you to do would tell you really quick.
Now I also wonder could the Advance weights get stuck advance when hot? Might try tapping the distributor with a hammer and see if that changes anything.
Dave ----
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Mountain Pass
Joined: Jan 2021
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From: North Of Dallas
I'll try the cable test and hammer. but was thinking, could my open exhaust manifold be causing issues. I plan to put it back on this weekend but was wondering. also, I failed to mention this started after the head gasket job.
More Turbo
Joined: Oct 2020
Posts: 529
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From: Houston
[QUOTE=kr98664;20067996]. Unless you have a money tree. I tried planting one years ago but it never bore any fruit. I think the soil PH was wrong.
Oh, Karl, I just lost some respect for you. Don't you know you must pee on the tree? Don't believe me? Ask Burt Munro.
Oh, Karl, I just lost some respect for you. Don't you know you must pee on the tree? Don't believe me? Ask Burt Munro.
Lead Driver
Joined: Nov 2013
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Possibly. Maybe without normal back pressure, the engine won’t run well unless you give it lots of timing advance. That “fixes” one problem, but creates another of overtaxing the poor starter system. Definitely get the engine back to normal configuration (exhaust connected, etc.) and readjust the timing before digging deeper into the slow cranking. Could be your starter system is fine but you were inadvertently asking too much of it.
This could be a red herring. The beginning of the problem may be due to the huge reduction in back pressure, and other than the open exhaust manifold, not caused by the head gasket replacement.
Of course this does beg the question: “Why was the head gasket replaced?”
This could be a red herring. The beginning of the problem may be due to the huge reduction in back pressure, and other than the open exhaust manifold, not caused by the head gasket replacement.
Of course this does beg the question: “Why was the head gasket replaced?”
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Mountain Pass
Joined: Jan 2021
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From: North Of Dallas