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Discussion Starter · #1 ·
I got an 83 c10 with a 305. I replaced the trans and once I did that I started finding problems. No spark I replaced hei distributor new plugs and wires. Started up fine but was having major carb issues I rebuilt the rochester q jet in the process of that I saw alot of damage from sitting pits in the bowl and other areas. Replaced carb with edelbrock performer. Fuel pump went out on first start so I replaced that with stock mechanical. Full vac system rebuild due to running really high rpms even with adjusting carb and distributor. I did full vacuum delete except vacuum advance and pcv set up that made it run a little better but now timing is advanced and it must be fully choked to start and I have to hold the pedal at half throttle till it warms up so it doesn't die. I checked vacuum at manifold and it sits at 10 hg I hit or hold throttle and it drops and holds at 0 I release throttle it shoots up to 15hg and drops back to 10hg. I am freaking stumped I've sprayed carb cleaner everywhere to check for vacuum leak and nothing I don't know what to do or check.
 

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that's alot to digest. start with the carb since you say you've eliminated the vacuum leaks. make sure there is a bit of freeplay in the throttle linkage / cable. adjust the idle curcuit and idle stop screw. adjust the choke, i assume it's electric.
then address the timing. you may need to go back to the carb if the timing was initially way off.
 

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Discussion Starter · #4 ·
In reply to Logan I think at this point I've checked firing order like 8 times. In reply to flopshot my goal for this weekend if weather ever clears is pull the intake manifold replace all gaskets reinstall and pull timing cover and inspect sprockets and chain and timing. Anything I need to inspect or check before I reassemble timing cover?
 

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1964 C-10-383 stroker-12 bolt posi & 1977 shortbox- nasty 454- 12 bolt posi 3:73
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Make sure your not gapped above .45. Check that your advance springs are moving freely..should be using medium springs. Check timing again..

Here's a link that has some hei tips..

 

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In reply to Logan I think at this point I've checked firing order like 8 times. In reply to flopshot my goal for this weekend if weather ever clears is pull the intake manifold replace all gaskets reinstall and pull timing cover and inspect sprockets and chain and timing. Anything I need to inspect or check before I reassemble timing cover?
not that i can think of.
 

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It all started with the trans replacement, your vacuum dropping from 15" to 10" indicates a leak. There's an electronic module that plugs into the HEI distributor that alters the timing.
It uses the vacuum line that feeds the modulator on the transmission as well as an electronic
relay. If there's a leak in that system it will cause all the problems you are having.
 

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Discussion Starter · #8 ·
It all started with the trans replacement, your vacuum dropping from 15" to 10" indicates a leak. There's an electronic module that plugs into the HEI distributor that alters the timing.
It uses the vacuum line that feeds the modulator on the transmission as well as an electronic
relay. If there's a leak in that system it will cause all the problems you are having.
So that system the ESC I ripped out it's not necessary when you replace the hei distributor with standard hei with just vacuum advance. At this point I replaced the timing gears and chain due to the amount slack and the face that the bottom timing mark was at 12 o'clock position and the top timing mark was at the 8 o'clock position I haven't had a chance to finish putting it back together due to being out of town but I will this weekend
 
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