March 16, 2025, 06:32:48 PM

Author Topic: SBC 350 Wont Start  (Read 2596 times)

Offline DRFT_HRD

SBC 350 Wont Start
« on: October 10, 2016, 08:06:26 PM »
Okay so I have been racking my brain trying to figure out why my SBC wont fire. Only thing that has changed since it was last running was a new starter, which works great but my 350 wont fire. I have timed and re timed it again and again. stock 350 with edelbrock 650 cfm 4 bbl carb. If i retard the timing a bit i get some fuel vapor out of the carb and burbling noises. If i set it to 2 degrees btdc  or advance it a bit more it just sits there cranking. Attached video is a example of the burbling noise im getting sorry for the heavy breathing, i have been sick so am mouth breathing sometimes and didnt realize i was holding my phone that close to my mouth. im getting fuel and spark and from the sound of it, getting compression. Any help would be appreciated as i only started messing with V8's a couple years ago aside from my truck.

http://vidmg.photobucket.com/albums/v517/Gizmo00/RX7/VIDEO0010_zpsgu1tokuv.mp4
« Last Edit: October 11, 2016, 04:49:51 PM by DRFT_HRD »

Offline gadzooks

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Re: SBC 350 Wont Start
« Reply #1 on: October 11, 2016, 09:47:54 PM »
are you sure you're not 180 degrees out on timing?
what happens if you dump a little fuel down the carb when you crank it?
are the float bowls full to the bottom of the check screw holes?
any different results if you hold the throttle open when cranking?
1987 Base/Light Weight with '95 Firebird LT1/T5

Offline DRFT_HRD

Re: SBC 350 Wont Start
« Reply #2 on: October 12, 2016, 09:02:56 AM »
are you sure you're not 180 degrees out on timing?
what happens if you dump a little fuel down the carb when you crank it?
are the float bowls full to the bottom of the check screw holes?
any different results if you hold the throttle open when cranking?

Fairly certain im not 180 out, checked for compression (pulled #1 plug and felt compression and pulled valve cover and watched for exhaust valve to open.) as i came around to tdc, if I dump in a bit of fuel it seems like it stutters a bit, same result when i hold the throttle open kinda like it might start, I will have to check the float bowls, carbs are sort of a mystery to me.
« Last Edit: October 12, 2016, 07:29:45 PM by DRFT_HRD »

Offline DRFT_HRD

Re: SBC 350 Wont Start
« Reply #3 on: October 12, 2016, 10:09:09 PM »
So slight update, messed arounf with the distributor and if i retarded it a decent amount i could get the car to run for a few seconds at a tim but it was super rough. Took a video and will post up in a bit. Going to reset tdc again tomorrow just to be sure im on and just try to get it timed well.

Offline Supe

Re: SBC 350 Wont Start
« Reply #4 on: October 13, 2016, 08:52:14 AM »
Sounds like distributor may be off a tooth.

Offline bikedad

Re: SBC 350 Wont Start
« Reply #5 on: October 13, 2016, 10:23:44 AM »
Pull the dizzy out. (is it an MSD billet or stock HEI?) My car had an MSD Pro Billet
Verify cap is installed correctly (MSD can be installed backwards. There are round and square alignment pins)
Verify rotor is good and installed correctly (Same as cap above)
Verify the cam gear pin is not sheared or cam gear is worn due to dissimilar components. Example: Steel, Bronze, Fiber
My MSD Dizzy needed a new magnetic pickup due to moisture getting under the cap. It would work sometimes and then no spark etc. I rebuilt the entire distributor

Verify TDC on #1 piston (Pull valve cover)
Insert distributor into block taking notice of 2 detents to seat it. One is aligning the oil pump drive pin to cam gear. Notice where rotor is pointing
Remove dizzy
Turn oil pump drive pin to align with cam gear close to where rotor will point to #1 plug wire on cap (I mark the side of distributor) . ( you can use a long screw driver)
Reinsert dizzy into block with rotor pointing close to #1 plug wire on cap after the second detent. Advance the distributor about a 1/4 turn. (This sets it at about 8 degrees advanced to alleviate backfire through carb etc)
Tighten distributor nut to create friction but allow you to advance with pressure. (keeps it from returning to original position)
Hook up timing light
(Buy yourself a remote start button. They're cheap and make life easy)
attempt to start car and hopefully set timing.
Set timing per your cam card
If it works have beer.  :chug:

Good luck
Don Teifke  :drive:
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