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Old 12-11-2021, 09:52 PM   #26
53burb
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Re: SBC starting issue

did you happen to pull a spark plug out to verify that it is getting spark when you crank it in the start position?
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Old 12-11-2021, 10:19 PM   #27
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Re: SBC starting issue

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Originally Posted by Slammo View Post
Thanks for all of the reply’s and suggestions. Yanked the headers off and checked compression today, all cylinders are between 140-150. Timing seems to be dead on. #1 cylinder at TDC, timing marks are good and distributor is pointed at #1 plug. Cranking it over by hand, no slop at all at the distributor. Definitely getting fuel to the cylinders. As mentioned earlier, I tried a new distributor, cap and wires. Plugs have a few thousand miles on them at most.
By all regulations if you have the firing order wired right (clockwise) 1-8-4-6-3-5-7-2 And are getting a spark out of the end of a plug wire when you crank it, it should fire and run. Everything else looks spot on.
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Old 12-12-2021, 12:33 AM   #28
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Post Re: SBC starting issue

what do you have for spark? have you gapped the plugs according to an hei dizzy with a stock com0ression ratio? .045? spark should be a nice hot blue zap that easily jumps a decent gap. hei is usually no slouch when it sparks. if you don't have a spark tester they are cheap or easy to make, maybe worthwhile?
have you checked your firing order? vac leaks? advance mechanisms?
fuel, air, compression, spark. air needs to get in and out easily. fuel ratio needs to be close enough. sounds like you have fuel, ratio who knows. have you pulled a plug after cranking to see if it is wet or dry? the air segment is assuming the carb is within spec or a known good runner previously and there are no vac leaks. maybe worthwhile to plug any vac ports not needed to run just to be sure your booster isn't stealing vacuum. compression you have verified but how many cranks did it take t get the readings? throttle pinned wide open when testing? readings come up on each cylinder at about the same number of cranks?
sometimes I have simply poured a little gas down the carb throat, installed the air cleaner loosely to quell any backfires, and then cranked it. it should fire if it has compression and spark. it may run out of gas right away and quit but then at least you know it is capable. of course that is with dry plugs to start with. and after you have verified spark while cranking.
hei dizzy needs a 12 volt supply via a 12 ga wire. if your truck had a points system before and wasn't wired for an hei specifically then that is another place to eat up some time and money. here is a copy and paste since I couldn't get the thing to make a link. it's all about converting bto hei from points to hei


Oldsmobile HEI distributors are a dime a dozen in the salvage yard and nearly as cheap. Their advantages over points distributors include: virtually no maintenance and a hotter spark. The disadvantages are: increased size that may require using a "persuader" to gain air cleaner clearance, and the obvious non-stock look.
If you decide to do it, the conversion is easy. As shown here, the typical points system uses an inline resistor or resistance wire between the ignition switch and the coil (+) terminal to avoid burning out the points.

On mid '60's and up vehicles this is typically a 20 gauge white/multistriped resistance wire installed between the coil the firewall bulkhead connector. A full 12 volts only during "crank" (start-up) is provided by a bypass wire running between the starter solenoid "R" and coil (+) terminal.

This is typically a 20-gauge yellow wire. The separate coil also requires low-tension and high-tension hookups to the distributor.

In order to run properly, an HEI requires a full 12 volts at all times. The 20-gauge resistance wire must be replaced by a 12-gauge wire (pink to maintain the factory colour coding), hooked up to the HEI cap's "BAT" terminal. If you don't want the hassle of getting into the bulkhead connector, splice the new wire into the existing 12 gauge pink wires on the instrument-panel side of the firewall that run to the ignition terminal and/or fuse box. Discard or tape off the yellow bypass wire and low and high tension leads. If so equipped, connect the electric tach wire (20 gauge brown) to the "TACH" terminal.

The three wire connector from the HEI distributor plugs into the three wire inner receptacle on the HEI cap marked C-, GRND, and B+ (it's keyed to only go on one way.)

Car improvements don't get any easier than this.

back to the OldsZone back to Tech.

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Old 12-12-2021, 02:26 AM   #29
01spirit750
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Re: SBC starting issue

Bad Coil?
So I know you said you replaced the distributer, but do not recall if you also said you replaced the distribute cap and coil?

Flakey coils can be a very odd beast. I had driven my OT SBC with HEI on a trip for 100 miles, pulled upto my GF's house and left it running, put it in reverse and engine died. I could get it to run "badly" by retarding the timing. Replaced the coil and all is good.
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Old 12-12-2021, 05:25 AM   #30
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Re: SBC starting issue

The link to the photobucket album I posted in an earlier post has the directions to check a coil with an ohm meter.
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My ongoing truck projects:
48 Chev 3100 that will run a 292 Six.
71 GMC 2500 that is getting a Cad 500 transplant.
77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.
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Old 12-12-2021, 05:34 AM   #31
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Re: SBC starting issue

Here, are all the pages. Sometimes I have my doubts that people actually make an effort to open one of the photobucket pages that I have put together to help.




















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My ongoing truck projects:
48 Chev 3100 that will run a 292 Six.
71 GMC 2500 that is getting a Cad 500 transplant.
77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.
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Old 12-12-2021, 10:58 AM   #32
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Re: SBC starting issue

Quote:
Originally Posted by 53burb View Post
did you happen to pull a spark plug out to verify that it is getting spark when you crank it in the start position?
Yes
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Old 12-12-2021, 11:33 AM   #33
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Re: SBC starting issue

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Originally Posted by 53burb View Post
did you happen to pull a spark plug out to verify that it is getting spark when you crank it in the start position?
Yes
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Old 12-12-2021, 06:37 PM   #34
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Re: SBC starting issue

A multimeter and test wire w/bulb can be your friend. Ever check wires in steering column? Sure sounds electrical.
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Old 12-12-2021, 10:48 PM   #35
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Re: SBC starting issue

I don't see one reason that engine won't start and run unless you just flat did something wrong.

You have fuel
you have spark
you have right on specs compression
It appears to be in time.

That means it should either run or at least backfire.

This should be the correct 350 HEI spark plug wiring diagram courtesy of 73.87com
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My ongoing truck projects:
48 Chev 3100 that will run a 292 Six.
71 GMC 2500 that is getting a Cad 500 transplant.
77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.
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Old 12-13-2021, 07:33 PM   #36
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Re: SBC starting issue

any news? does it start? backfire? you figured out how to postb pics and are assembling an album before posting? did you burn it down from frustration and you have a new project with a build thread on a ford site? haha.
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Old 12-13-2021, 07:37 PM   #37
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Re: SBC starting issue

he musta got it running and is "burnishing the tires" right now.
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Old 12-17-2021, 03:59 AM   #38
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Re: SBC starting issue

Feedback is always nice, but I do understand that a lot of guys have limited time to work on their projects and especially at this time of year due to other demands and a kid's or grand kid's Christmas program or ball game or other obligations are every bit as important as working on the truck project. If he knew that one of my kids was involved in something my dad would take time off and drive 160 miles to whatever they had going on but my mom wouldn't take the time to drive 10 miles to the same event and my kids full and well remember that. If they told granddad they had something going on he showed up.
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My ongoing truck projects:
48 Chev 3100 that will run a 292 Six.
71 GMC 2500 that is getting a Cad 500 transplant.
77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.
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Old 12-18-2021, 08:00 PM   #39
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Re: SBC starting issue

I had this same just cut off. No shutter no fuel starve just off.
Ended up being a pinched wire. Not enough to blow fused
Just enough to draw the electrical way down.

Straight wire it. Like engine to battery with nothinG else attached except engine run essentials only. Like electric fuel pump. . Use a remote start wire to get it running. Only way to stop is pull negative from battery etc. Then drive if it stays running the whole time it’s a electric issue somewhere other than engine. If it stops it is in the hei or coils etc. it’s screaming electrical witH that just stop no staving stop etc.
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Old 12-18-2021, 08:01 PM   #40
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Re: SBC starting issue

Mine pinched wire only happened on cab shifting when a bounce occurred. Real pain to find.
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Old 12-20-2021, 04:04 PM   #41
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Re: SBC starting issue

Hcb, I like your idea and have done that often when I was working in the truck shop. I even had a harness with a couple of switches wired up for a quick "grab and test" routine that allowed me to switch battery power on to the dizzy and also a push button for the starter. this eliminates everything else so you know if the engine starts and runs like normal if the vehicle wiring is removed from the equation. I use it for motorcycles and other things as well.
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Old 01-02-2022, 08:00 PM   #42
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Re: SBC starting issue

Well, I went through the wiring 2 weeks ago to check for possible shorts, found nothing. In the meantime, I decided to order another new $60 HEI distributor from Amazon. Finally got around to installing it today…fired right up. I’m guessing the 1st one took a dump, which began this ordeal. The 2nd one, although new, must have had an issue. I guess that’s to be expected for buying a $60 distributor. I plan on going with an LS swap this year, hence the reason for not buying a quality distributor…serves me right.
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Old 01-02-2022, 08:08 PM   #43
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Re: SBC starting issue

Bet that felt good hearing it run.
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Old 01-02-2022, 08:30 PM   #44
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Re: SBC starting issue

Good Deal

Now you know.
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Old 01-02-2022, 10:00 PM   #45
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Bet that felt good hearing it run.
Absolutely…music to my ears!
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