79 vette with 350 wont start

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79 vette with 350 wont start

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Corvette Forums >> Corvette Models >> Corvette C3 Forum >> 79 vette with 350 wont start

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79 vette with 350 wont start - 6/14/2007 10:49:15 PM

vettec3

Posts: 1
Joined: 6/14/2007
Status: offline

ok ive got a age old problem with new twist....reciently i completely rebuilt a 79 350 corvette ...orgionally an L48 with four barrel carb... i rebuilt a different 350 block of same period except a 4 bolt main instead of a 2 bolt ...all new everything and put new heads on set up for an L82 but that just means bigger valves... i get spark and with the new added on ..inline electric fuel pump i get fuel and i pump throttle on carb and can see gas sqirting into carb ....I followed book to the letter on timing and according to the shop manual crank, cam , and distributor all exactly as they should be timed...

But still no matter what i do the car turns over but will not start... pops a little here and there but nothing..... before the rebuild the carb was rebuilt a year prior so i know it should be still ok ..but to my amazement the OEM block for years had a dead cylinder still ran and previous owner (my father) had no clue so the carb was adjusted to technically a 7 cylinder motor but ran without issue.

So basically everything that says the car should run adds up to no go... not sure exact year of block but same cast number as OEM one...wondering if fireing order changed with in those years or with L82 heads could air fuel mixture need adjustment im not aware of...............any ideas..?... thanks mike

Post #: 1

RE: 79 vette with 350 wont start - 6/15/2007 3:07:44 AM

78buckshot

Posts: 654
Joined: 1/28/2007
From: Michigan
Status: offline

Welcome to the forum vettec3, don't get discouraged, hang in there with us and we'll get her fired up for ya. Rigth off the bat I would not worry about the carb, it sounds like an ignition and/or timing issue to me. there are two timing areas to consider, (1) the valve timing, this is done while your setting up the cam sprockets and chain. it is common to have this set up with the timing marks 180 degrees off in which case you could crank all day and only get an occasional pop if all else is correct. The second area of timing is spark, this is set up while installing the distributor, I can only assume your still using the stock HEI ignition. Pull the driver side valve cover and observe the intake and exhuast valve for the #1 cylinder, this is the front left cylinder, all the chevy V8's had the same firing order-18436572, get the #1 piston at top dead center with both valves closed and the timing mark on the balancer should now be lined up at or very close to TDC or 0 degrees, it's the long mark or deepest notch in the timing tag. Now check the distributor and see if the rotor is pointing to the #1 terminal on the dist. cap. If all of these are lined up then your valve and spark timing should be close enough to get it running, if one or both are not lining up you'll have to address that area of timing. If the valve timing is 180 degrees off you can pull the distributor and point the rotor to the terminal 180 degrees from #1 and re-install, if it fires now you'll know the cam timing marks are off 180 degrees. Try this and get back to us,good luck.

(in reply to vettec3)

Post #: 2