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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: user85 on May 03, 2009, 09:44:32 pm
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new to the forum. I have an 85 chevy c10 120000 miles 305 vin H and 350 turbo w/ lockup. I recently bought the truck and while driving i notice a very slight ping when going up a hill and when the tcc applies other than that truck runs fine. I have replaced the spark plugs vacuum advance and reset base timing to 4 and vacuum advance to manifold vacuum. Truck has no esc or egr. the lockup was disconnected when purchased so i hooked it back up. i felt it came on too soon so i wired a switch off the brown wire out of the fuse block that goes to the brake light switch to turn it on when speed is more around 45 instead of 35.I am extremely picky when it comes to vehicles. I was wondering if this is normal or am I expecting too much from a 25 year old truck
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welcome aboard!
for the pinging, i'd retard (turn clockwise) the timing a tad until you don't hear the pinging under load. Maybe 6 BTDC and see if you hear the rattling...if not, advance slightly---you'll find a sweet spot there somewhere with a little playing.
make sure you check the timing when advance is not hooked up and plugged the vacuum line.
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try running a cooler tstat and run some sea foam or top engine cleaner through it. Make sure you are using the correct spark plug heat range also.
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i am running r45ts ac delco plugs. Is this the correct plug that is what is on the sticker under the hood.
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Those plugs were superceded with a colder plug because of pinging. Try a set of R43CTS and see what happens. That may be your whole problem.
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replaced plugs w/ r43ts still pings so i remembered i replaced vac advance the same time i fixed the lockup. I unhooked the vac advance and drove it no ping. Increased base timing to 8btdc no ping. I have an esc dristributor that has been bypassed is the vacuum advance different from older types in that it has more advance
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Just get a non esc distributor, they're cheap enough.
http://cgi.ebay.com/ebaymotors/SBC-BBC-350-383-CHEVY-SUPER-65K-HEI-DISTRIBUTOR-6500-R_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1171Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1309Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem3ef4227c3bQQitemZ270383873083QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
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update seafoamed and replaced distributor and hooked up new vacuum advance truck runs great but still has the ping with lockup.Filled up with 92 octane and no ping at all gas mileage increased because i can run vacuum advance so I am happy with it and ok with using higher octane gas. I bought the distributor VileZambonie suggested and what a nice piece my truck has never ran better. Thanks to all who replied.
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Glad to hear. Is your EGR working?
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no egr has been blocked off.
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... If you reconnect the EGR your pinging will go away but if you don't mind running higher octane then leave it be.
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Yep, the lack of EGR is the problem.