Author Topic: Important various questions  (Read 2043 times)

Offline 1978Bonanza

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Important various questions
« on: May 09, 2008, 09:56:23 PM »
Ok I did a compression check today. It is a 1983 350 4 barrel in a 1978 c-20. Cyl. 1 was 35  :o, Cyl. 3 was 50  :-[, cyl. 4 was 85  :-\, the rest were over 100. What could be the problem? Could I need heads re-machined?


Next is the seafoam, Im going to seafoam my engine tomarrow. My teacher told me to pour some in the carb and take the spark plugs out and pour it in the holes, let it sit overnight and start it next morning. Sound right? But I have old spark plugs in there right now. Should I seafoam it with the old spark plugs or new ones?

Next what are the best spark plugs for my truck? Last time I got autolite copper cores.



Thank you so much!

Offline VileZambonie

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Re: Important various questions
« Reply #1 on: May 10, 2008, 08:01:27 AM »
Did you do the compression test correctly?

Engine warm, all spark plugs removed, ign disabled, battery charger installed, Wide Open Throttle 4 compression strokes each cylinder?

If you did it correctly then repeat the test with 2 squirts of oil in the cylinder and report your results.
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Offline HAULIN IT

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Re: Important various questions
« Reply #2 on: May 10, 2008, 08:03:40 AM »
Bonanza, You definitely got some problems there. Is this/has been a running engine recently or has it been sitting? At this point, a leak down test (or just compressed air in the spark plug hole) would be a good start. With both valves on that cylinder closed, If the air comes out the carb - intake valve, out the exhaust - exhaust valve, out the breather,pcv, dipstick - rings,ect. A bum cam is also a possibility. Maybe remove the valve covers & watch the rockers move on those cylinders compared to the others, or better, set-up a dial indicator & measure, but I don't think with that low, if it's the problem, you'll be able to see it. I've not heard of Seafoam, I'm guessing it's like GM's Top engine cleaner? I'm concerned with the "pour it in the spark plug holes & then start it" This sounds like a possibility to hydraulic the engine to me. Autolite....Autolite! GM used AC in their vehicles for a reason, also the NGK's seem to be good. Autolite? Lorne

Offline 1978Bonanza

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Re: Important various questions
« Reply #3 on: May 10, 2008, 10:41:26 AM »
I believe the engine was warm. Yes spark plugs were removed, WOT, ignition was in because I turned the key from the inside to crank it, and a battery charger was not installed. The engine has been running recently but definitely not 100%.

Offline 1978Bonanza

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Re: Important various questions
« Reply #4 on: May 11, 2008, 11:11:40 AM »
Well I decided this old truck is not for me. Im either going to part it out or sell it. I spend and spend and spend, but never get anywhere. Im done with it, gas is high, mpg is low. It just always needs but I just cant justify spending everything I have for a POS truck.

Offline frogman68

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Re: Important various questions
« Reply #5 on: May 11, 2008, 05:01:39 PM »
Well I decided this old truck is not for me. Im either going to part it out or sell it. I spend and spend and spend, but never get anywhere. Im done with it, gas is high, mpg is low. It just always needs but I just cant justify spending everything I have for a POS truck.

Dont give up, You are young keep it together and just fix it a little at a time. I have 99.9 percent of the parts I need to finish mine I just dont have the time  :'(.

I dont remember the last time I even looked at mine find a economical beater to run around in and just go slow