Slow starting when hot
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Slow starting when hot
Hi, i have a 1977 f-150 with a 351m engine. Engine starts fine when cold. However, after the engine is hot and i shut it down, it is slow to restart. I replaced the battery, solenoid switch, starter, and cables. This seemed to have helped alot. But, at times, it still does it. any ideas would be appreciated.
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From: southern cal.
I have heard many people say advanced timing can cause hot start problems. I am having a hot start problem right now. Exactly how does advanced timing make it harder to turn the engine over when it is hot?
Also, in my case the post on the solenoid connected to the battery gets very hot. Why?
Sorry for the hijack....These answers may help us all.
Don
Also, in my case the post on the solenoid connected to the battery gets very hot. Why?
Sorry for the hijack....These answers may help us all.
Don
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With the slow starting speed of the starter and advanced ignition timing once a cylinder fires the engine will actually want to go BACKWARDS since the piston/ rotating assembly doesn't have enough speed inertia to overcome the pulse.
That's why with a hot engine and extremely advanced timing you'll hear the engine go ERR... ERR... ERR... instead of ERERERERER (lame I know)
A stock or mild cam can only take so much initial advance before problems occur. That's why most stock engines are in the 6-8 range.
A lot of factors cause a hot start problem. Battery condition, starter condition, cables, timing, carb rich or lean, choke setting etc.
The most basic thing to do which is usually free is to check the setting of timing, choke and condition of the cables/ ground. From there you can check the battery and the most time consuming pulling the starter and having that tested.
Josh
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If your cables are getting hot, you have a poor connection somewhere OR a weak/HOT starter. My 300-6 with headers cooks my starter big time resulting in lot's of heat soak. Reminds me, I gotta get some heat wrap/shield on that baby!
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From: Sterling, CT
check your ground. a friend had a bad connection on the block. when he would try to start it when it was warm the block connection would start glowing..........................Good Luck
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There is a sticker on my valve cover that says for the ignition timing to be set at 14 degrees btdc but, as i dont have a timing light, i havnt checked it yet. I too noticed that the cable on the starter side of the solenoid was extremely hot whenever i went to replace it. I used 4 gauge cables. Yea, i can see how if the spark is occuring too early on an already warm engine it would make it hard for the starter to turn the engine. Good info.
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Joined: May 2005
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From: southern cal.
There is a sticker on my valve cover that says for the ignition timing to be set at 14 degrees btdc but, as i dont have a timing light, i havnt checked it yet. I too noticed that the cable on the starter side of the solenoid was extremely hot whenever i went to replace it. I used 4 gauge cables. Yea, i can see how if the spark is occuring too early on an already warm engine it would make it hard for the starter to turn the engine. Good info.
Don
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Not sure but i think what is meant by this is that if the piston has more time to travel upward before the combustion process begins, it develops more inertia thus helping the starter continue turn the engine. May be wrong thats just how i picture it in my mind. It's easier for the power pulse to make the crankshaft want to kick back against the starter if the piston is lower in the bore.
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If im correct, anytime the key is on and the engine is turning, the spark plugs are firing. Since the distributor is in constant mesh with the camshaft which is directly linked to the crankshaft. So, yes, i would say that during startup the ignition coil is energized and the distributor is turning thus breaking the primary field in the coil and inducing higher voltage into the secondary field and distributing it according to firing order to the spark plugs.
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With far advanced timing the starter is fighting the combustion, which the starter is already been kicked down a couple pegs from being burning hot from the engine and exhaust heat.
That's why a hot engine is harder to turn over than a cold one.
Josh