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my 81 chevy sounds strange when starting


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ssdude
Novice

Jan 2, 2010, 4:57 PM

Post #1 of 18 (1864 views)
post icon my 81 chevy sounds strange when starting Sign In

my 1981 is not starting when it cranks over it will crank for a few seconds then it slows down a few turns then gose back. what is wrong?


Loren Champlain Sr
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Jan 2, 2010, 5:32 PM

Post #2 of 18 (1859 views)
Re: my 81 chevy sounds strange when starting Sign In

then it slows down a few turns then gose back>>
SSDude; I'm not sure what you mean by that? After reading both posts, check the choke. With the engine cold, it should be closed with a slight spring tension. As soon as the engine starts, it should open about 1/8". If it doesn't, this will cause a flooding condition. If it floods badly enough, the fuel can wash away the lubricant in the cylinders causing a loss of compression. But, if that happens, the engine would crank over faster than 'normal'. With what you posted, it sounds as if it may be cranking very slowly. Have the battery fully charged and load tested. Check the cables. Make sure they are clean at both the battery ends and the starter/ground connections. The 454 requires a LOT of cranking amps and will need every bit of what the battery can supply, especially when cold. If you can give us more symptoms, may help? Let us know what you find after these checks. We can go from there.
Loren
SW Washington


ssdude
Novice

Jan 2, 2010, 5:44 PM

Post #3 of 18 (1857 views)
Re: my 81 chevy sounds strange when starting Sign In

i have checked the choke it dose not open at all. and the battery is brand new the positive battery cable is getting kind of hot. the engine is cranking slower but will go for a few minutes.


steve01832
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Jan 2, 2010, 6:06 PM

Post #4 of 18 (1853 views)
Re: my 81 chevy sounds strange when starting Sign In

A lot of times when cranking, if the crank rpm slows then speeds up and the engine doesn't start, check the timing chain. An engine that has jumped time will sound like this. I remember the older GM 3.8 liter engines with the teflon gears had this happen at 60000 miles.

Steve


Loren Champlain Sr
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Jan 2, 2010, 6:14 PM

Post #5 of 18 (1849 views)
Re: my 81 chevy sounds strange when starting Sign In

SSDude; Make sure that the battery is GOOD. The battery can be fully charged, 13.2V, but still not have the cranking amps needed. A load test will confirm. Could be that the starter is drawing too many amps. It's best to have the starter draw tested while in the vehicle. As Steve mentioned, timing can come into the picture, but generally when the engine is warm. Disconnect the power to the distributor and crank the engine. If it cranks normal, then the timing is over-advanced for whatever reason. The choke is opened by a vacuum operated diaghragm. Of course, the engine must be running fairly decently to supply this vacuum. Cranking speed is important. Once that is addressed, you can manually open the choke if need be.
Loren
SW Washington


steve01832
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Jan 2, 2010, 6:19 PM

Post #6 of 18 (1846 views)
Re: my 81 chevy sounds strange when starting Sign In

OMG. I think I am over-celebtating New Year's. I completely missed ssdude's post about the choke not opening and the battery cable heating up. Sorry man, I think I should call it a night and sleep this one off. lol
Thanks Loren!!!

Steve


Loren Champlain Sr
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Jan 2, 2010, 6:24 PM

Post #7 of 18 (1844 views)
Re: my 81 chevy sounds strange when starting Sign In

Steve; << Sorry man, I think I should call it a night and sleep this one off. lol >> Absolutely, NOT. You brought up a very valid point....I had overlooked the timing possiblity. Here's to ya;
Some Capt. Morgan's Spiced Rum is in order! Have a great weekend.WinkWinkSmileSmile
Loren
SW Washington


steve01832
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Jan 2, 2010, 6:27 PM

Post #8 of 18 (1841 views)
Re: my 81 chevy sounds strange when starting Sign In

Loren, at my age (41) about all I can handle is Miller High Life. But, I CAN handle 18 or so before I start overlooking people's posts. lol

You too, have a great weekend.

Steve


Loren Champlain Sr
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Jan 2, 2010, 6:35 PM

Post #9 of 18 (1840 views)
Re: my 81 chevy sounds strange when starting Sign In

Steve; MGD is okay. Unsure 41? Geez, you're just a kid. LMAO. 18? A lightweight, huh? ROFLMAO. What is it with us mechanics? Just wonder how many of us really drink, or just joke about it? LOL. Doesn't matter, as long as we have fun...I'm approaching 58. One of my techs turned 49 on Thus. He asked me how it felt to be 49. I told him that it was so long ago, I couldn't remember. Have a great weekend. Back to it on Monday.
Loren
SW Washington


steve01832
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Jan 2, 2010, 6:59 PM

Post #10 of 18 (1832 views)
Re: my 81 chevy sounds strange when starting Sign In

18? OOPS, forgot the decimal point. 1.8. That's better. lol

Steve


Loren Champlain Sr
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Jan 2, 2010, 7:24 PM

Post #11 of 18 (1829 views)
Re: my 81 chevy sounds strange when starting Sign In

Steve; You crack me up! 1.8? LMAO....Now, you're sounding like Sidom. btw, Sidom, you nursing a hang over? LOL>
Loren
SW Washington


ssdude
Novice

Jan 2, 2010, 7:43 PM

Post #12 of 18 (1828 views)
Re: my 81 chevy sounds strange when starting Sign In

thank you guys for your in put so far. i disconnected the power from the distributor and it is still cranking the same. i am still going to try the timing next. what would i need to test the timing?
again thank you both for your advise.
Justin


re-tired
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Jan 2, 2010, 7:45 PM

Post #13 of 18 (1824 views)
Re: my 81 chevy sounds strange when starting Sign In

 btw, Sidom, you nursing a hang over? LOL>

No he's just nursing Shocked



LIFE'S SHORT GO FISH


Loren Champlain Sr
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Jan 2, 2010, 7:48 PM

Post #14 of 18 (1821 views)
Re: my 81 chevy sounds strange when starting Sign In

 he's just nursing Shocked
My favorite pastime.

Loren
SW Washington


steve01832
Veteran
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Jan 3, 2010, 3:11 AM

Post #15 of 18 (1810 views)
Re: my 81 chevy sounds strange when starting Sign In

SSdude. Here is a quick test. Note cylinder 1 position on the distributor cap. Remove cylinder 1 spark plug. Unplug the primary wire connector from ignition coil. Have an assistant bump the engine over with the key until you hear the compression hiss from the cylinder, then turn ignition off. Rotate the crankshaft pulley counter-clockwise until the timing mark lines up with 0* top dead center. Remove the distributor cap, if the rotor is pointing at #1 cylinder of cap, timing chain is OK. If rotor points to a different cylinder, timing chain has jumped. Please post back with the findings. Thanks.

Steve


ssdude
Novice

Jan 3, 2010, 12:29 PM

Post #16 of 18 (1794 views)
Re: my 81 chevy sounds strange when starting Sign In

hey Steve. i did what you told me with the distributor and i didn't hear any hissing . and i want to add that the new battery i bought yesterday and it is already drained i left it overnight and now its very low. suggestions?


steve01832
Veteran
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Jan 3, 2010, 1:54 PM

Post #17 of 18 (1788 views)
Re: my 81 chevy sounds strange when starting Sign In

If you didn't hear a puff, you can plug the spark plug hole with your finger. Do be careful of moving parts please. The compression should be strong enough to feel.
If you put a new battery in last night and it is weak, you probably have a parasitic draw. If you have a non powered test light you can disconnect the negative cable from the battery. Put the test light clip on the battery post and touch the probe to the cable. If the light is on bright, you can start by unplugging fuses one at a time. When the light goes out you have narrowed the draw down to the fuse's circuit(s).

Steve


ssdude
Novice

Jan 3, 2010, 7:56 PM

Post #18 of 18 (1775 views)
post icon Re: my 81 chevy sounds strange when starting Sign In

i bought a timing light but i don't think I'm using it right. any suggestions?


(This post was edited by ssdude on Jan 4, 2010, 4:02 PM)






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