Experienced Mechanic needs another opinion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cypress TX 72 · 02-12-2006, 09:05 PM

I have a 350 SB that will not start....
I have fuel getting to the carb, plugs are moist but not flooded.
I have fire to the plugs.
When turning the motor over, it wants to start... but just won't.
I changed the coil in the HEI and tried again (thinking I wasn't getting enough spark)-- still no dice...
So I re-timed it by hand, TDC and re-aligned the rotor in the HEI..Just to make sure.
Still no dice...
The only other thing I can think is the modulator in the HEI is bad, or that the motor has jumped time.
This motor is fresh, it has about 4 hours on it, and the HEI is brand spanking new.
Please Help me out with some ideas.

68cajun · 02-12-2006, 09:11 PM

When you say you retimed it, was the dizzy out, or did it line up ok?

Russell · 02-12-2006, 09:14 PM

sounds like timing to me!

When I set it, I always use a timing light, even setting it by hand. Basically, I find TDC with the truck, making 100% sure I am on the compression stroke using a compression tester with the gauge taken off (makes a whistling noise when air goes through it), then stab the dizzy base in. After I have the base in, I install the cap + wires as close to where they should be as I can, and button it up, less the timing adjustment bolt.

I then turn the ignition to ON, and put my inductive timing light onto plug wire number one. I then grab the dizzy cap, and turn it back and forth. Every time you spin past number 1, it should fire, and make the timing light flash. So, get it set as close to number 1 as you can, then tighten the dizzy cap a bit more, and try my best to start it.

Sometimes you gotta put the idle screw way in so it'll keep running long enough for you to get around front, and set the timing with the light properly.

Make sure you unplug your vac advance when you set the timing, and that your idle is low enough that you arn't getting any mechanical advance. This is crucial, cause as you get closer to the proper timing, she'll idle a bunch, due to you having the idle screw in, so set it to where it should be, turn the idle down, set it again, turn the idle down, set it, etc etc.

RainFade · 02-12-2006, 09:19 PM

Module or pickup coil in hei ?, timing chain jumped ?

Chevrolet4x4s · 02-12-2006, 09:34 PM

look at the little peg(can't remember th proper name for it)inside center of cap they will burn up over time.

Frizzle Fry · 02-12-2006, 09:41 PM

Open port on the carb or intake???

kelsfine69 · 02-12-2006, 09:47 PM

Make sure you have 12v in "start" and "run". I have seen where they have 12v in start but as soon as you let go of the key to the run position there is no 12v anymore. It wants to start but then quicky dies when you let go of the key......M2C worth

**VetteVet** · 02-12-2006, 09:51 PM

Could it be 180 degrees out on the distributer? You said the engine had 4 hours on it . Did it just all of a sudden decide not to start or did you get a backfire and then it wouldn't start?

cypress TX 72 · 02-12-2006, 09:51 PM

Russell,
I know I have the motor at TDC, by my finger, exhaust sucks and compression blows my finger out...
Balancer and marker lined up at zero, a little retarded by close enough to start... Rotor at #1 plug...
My problem is that it won't start, Once I get it running I can finalize the timing.
I need to easly determine in the chain jumped.
I guess I could check to see it fire and mark happens at the same time.
but thats kinda tough being a one man army...
I have an old HEI, i'll try and clean up and drop it in tomorrow and see if I can eliminate it to the Distributor

cypress TX 72 · 02-12-2006, 09:55 PM

Vet vet,
It ran fine, then sat up for about 2 years, I started it up on Super Bowl Sunday, ran great, Then Monday I moved it out and let it run for a few minutes, when I went to put it up, it ran real rough and real rich, the barked a little when I shut it off.
Then today it just wouldn't start.

**72ironmike** · 02-12-2006, 10:01 PM

I hate to be such a simpleton here, but do you have good gas?

cypress TX 72 · 02-12-2006, 10:11 PM

Mike,
Yea, I drained and refueled

68cajun · 02-12-2006, 10:26 PM

Could it be stuck floats in the carb? Maybe gummed up?

cdowns · 02-12-2006, 10:41 PM

did you run a new wire to the HEI or is the original (resistor circuit)wiring being used ???

cypress TX 72 · 02-12-2006, 11:33 PM

68 Cajun,
If the floats were stuck, wouldn't the plugs be saturated?
The plugs now are pretty dry, but I can see fuel dripping down the throat when I hold the primarys open and work the accelerator pump.
I also tried to start it spraying Gumout directly down the primarys while turning it over.

Cdowns,
I did run a new wire during the restore, I checked volatge with the key "on" at the harness going into the "BAT" terminal on the cap- I have 12.4 volts
What do you think besides that - do you think I should check if its holding voltage while I am trying to start it ???
appreciate the help guys.
Cypress

*rage'nrat638* · 02-12-2006, 11:45 PM

sounds like a problem with the dizzy or timing
remove cap and turn over make sure rotor in turning smooth
my first try would be to pull the dizzy out. and inspect
bottom gear, screw-clip crap near poll piece.bad broken poll piece wire
got a points dizzy to put in.or another hei to test
make sure rotor is at number 1 on cap on tdc

corn · 02-13-2006, 12:47 AM

Im thinking its a fuel problem. If it ran fine one day & bad the next & you didnt change anything in between It cant hardly be a misaligned distributor or rotor. If the module went it wouldnt try to start like you said its doing. Id try a fuel filter or easier yet dump a little gas in the carb & see if it runs good for a second or two. If it does get a new pump or see if theres a carb crab. Good luck with it...corn

jhow66 · 02-13-2006, 01:13 AM

You have gas fouled plugs.

Rdrdave · 02-13-2006, 01:23 AM

check condition of rotor and cap...badly cracked or broken. I had that problem. Check the simplest and go for the worse. check wiring to HEI, then cap/rotor, then firing order, then plugs and so on. You'd be amazed how many little things keep an engine from starting.

69TowRig · 02-13-2006, 01:53 AM

Quote:

Originally Posted by Chevrolet4x4s

look at the little peg(can't remember th proper name for it)inside center of cap they will burn up over time.

You mean rotor button?

luisduran · 02-13-2006, 02:03 AM

SPARK PLUGS. Take one off, conect the wire and ground the plug on top of the engine and crank the engine over so you can see how much spark is going true the plug.

corn · 02-13-2006, 02:09 AM

Or condensation in the cap. WD-40

Tropical Snowstorm · 02-13-2006, 02:56 AM

Check for spark at the plugs.

Change the plugs out (if you have some more around).

Try leaving the key "on" and jumping the starter to eliminat an electrical problem while the ignition switch is at "start."

You say it was running as is a few weeks ago, so that eliminates the distributor being 180 out. Gas is fresh, so that's out. The only other thing I can say is maybe the valves aren't adjusted right/too tight and are either hanging open or staying closed or something else mechanical inside the engine.

Good luck with it, I hope it's something simple.

_Dick_ · 02-13-2006, 04:37 AM

if i understood you this thing sat for two years ,any one move in the exhaust system while it sat ,ie mud dobbers ,mice ,kids toys ect.

KFreddy · 02-13-2006, 05:02 AM

Check the fuel filter in the carb?

02-12-2006, 09:11 PM	#2
68cajun 68 C/10 Join Date: Oct 2003 Location: Houma Louisiana Posts: 367	Re: Experienced Mechanic needs another opinion When you say you retimed it, was the dizzy out, or did it line up ok? __________________ (2009) GMC Sierra Denali 6.2 AWD (67 C/10 fleetside SWB) (2018GMC Yukon Denali) Wifes Car

02-12-2006, 09:14 PM	#3
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Re: Experienced Mechanic needs another opinion sounds like timing to me! When I set it, I always use a timing light, even setting it by hand. Basically, I find TDC with the truck, making 100% sure I am on the compression stroke using a compression tester with the gauge taken off (makes a whistling noise when air goes through it), then stab the dizzy base in. After I have the base in, I install the cap + wires as close to where they should be as I can, and button it up, less the timing adjustment bolt. I then turn the ignition to ON, and put my inductive timing light onto plug wire number one. I then grab the dizzy cap, and turn it back and forth. Every time you spin past number 1, it should fire, and make the timing light flash. So, get it set as close to number 1 as you can, then tighten the dizzy cap a bit more, and try my best to start it. Sometimes you gotta put the idle screw way in so it'll keep running long enough for you to get around front, and set the timing with the light properly. Make sure you unplug your vac advance when you set the timing, and that your idle is low enough that you arn't getting any mechanical advance. This is crucial, cause as you get closer to the proper timing, she'll idle a bunch, due to you having the idle screw in, so set it to where it should be, turn the idle down, set it again, turn the idle down, set it, etc etc. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

02-12-2006, 09:19 PM	#4
RainFade Registered User Join Date: Nov 2004 Location: Central Ohio Posts: 215	Re: Experienced Mechanic needs another opinion Module or pickup coil in hei ?, timing chain jumped ? __________________ 71 K20 350/350/205, dealer air, 4" lift, Flowtech,Edel 1406 on 2101, procomp HEI,4.10's, 33x12.50x16.5 BFG MT's on slots. 4 wheel disc brakes. My lame K20 page My lame Eaton disc brake page

02-12-2006, 09:34 PM	#5
Chevrolet4x4s Registered User Join Date: Nov 2005 Location: WV Posts: 227	Re: Experienced Mechanic needs another opinion look at the little peg(can't remember th proper name for it)inside center of cap they will burn up over time. __________________ 1993 K1500 350 5 speed 1985 K10 Silverado Vortec 406 5 speed (in body shop) "I been drivin' this '85 pickup truck Them buddies of mine call it a bucket of rust She's a little beat up but she still runs like the wind Yeah, kinda like me I been banged and bruisedBeen around the block a time or two But I'm runnin' like new goin' places I never been No, I ain't broke I'm just broken in" 1963 Dodge Townwagon(its amazng what 30 years and zero miles will do to a vehicle ) Member#20327

02-12-2006, 09:41 PM	#6
Frizzle Fry Registered User Join Date: Aug 2005 Location: Hillsboro Oregon Posts: 6,449	Re: Experienced Mechanic needs another opinion Open port on the carb or intake???

02-12-2006, 09:05 PM	#1
cypress TX 72 Saving one 72 at a time!! Join Date: Sep 2005 Location: Cypress, TX Posts: 261	Experienced Mechanic needs another opinion I have a 350 SB that will not start.... I have fuel getting to the carb, plugs are moist but not flooded. I have fire to the plugs. When turning the motor over, it wants to start... but just won't. I changed the coil in the HEI and tried again (thinking I wasn't getting enough spark)-- still no dice... So I re-timed it by hand, TDC and re-aligned the rotor in the HEI..Just to make sure. Still no dice... The only other thing I can think is the modulator in the HEI is bad, or that the motor has jumped time. This motor is fresh, it has about 4 hours on it, and the HEI is brand spanking new. Please Help me out with some ideas.

02-12-2006, 09:47 PM	#7
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: Experienced Mechanic needs another opinion Make sure you have 12v in "start" and "run". I have seen where they have 12v in start but as soon as you let go of the key to the run position there is no 12v anymore. It wants to start but then quicky dies when you let go of the key......M2C worth __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

02-12-2006, 09:51 PM	#8
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: Experienced Mechanic needs another opinion Could it be 180 degrees out on the distributer? You said the engine had 4 hours on it . Did it just all of a sudden decide not to start or did you get a backfire and then it wouldn't start? __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

02-12-2006, 09:55 PM	#10
cypress TX 72 Saving one 72 at a time!! Join Date: Sep 2005 Location: Cypress, TX Posts: 261	Re: Experienced Mechanic needs another opinion Vet vet, It ran fine, then sat up for about 2 years, I started it up on Super Bowl Sunday, ran great, Then Monday I moved it out and let it run for a few minutes, when I went to put it up, it ran real rough and real rich, the barked a little when I shut it off. Then today it just wouldn't start.

02-12-2006, 10:01 PM	#11
72ironmike Senior Member Join Date: Jan 2004 Location: Olathe KS (Greater Kansas City MO Area) Posts: 2,048	Re: Experienced Mechanic needs another opinion I hate to be such a simpleton here, but do you have good gas?

02-12-2006, 10:11 PM	#12
cypress TX 72 Saving one 72 at a time!! Join Date: Sep 2005 Location: Cypress, TX Posts: 261	Re: Experienced Mechanic needs another opinion Mike, Yea, I drained and refueled

02-12-2006, 10:26 PM	#13
68cajun 68 C/10 Join Date: Oct 2003 Location: Houma Louisiana Posts: 367	Re: Experienced Mechanic needs another opinion Could it be stuck floats in the carb? Maybe gummed up? __________________ (2009) GMC Sierra Denali 6.2 AWD (67 C/10 fleetside SWB) (2018GMC Yukon Denali) Wifes Car Last edited by 68cajun; 02-12-2006 at 10:27 PM.

02-12-2006, 10:41 PM	#14
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Experienced Mechanic needs another opinion did you run a new wire to the HEI or is the original (resistor circuit)wiring being used ??? __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

02-12-2006, 11:33 PM	#15
cypress TX 72 Saving one 72 at a time!! Join Date: Sep 2005 Location: Cypress, TX Posts: 261	Re: Experienced Mechanic needs another opinion 68 Cajun, If the floats were stuck, wouldn't the plugs be saturated? The plugs now are pretty dry, but I can see fuel dripping down the throat when I hold the primarys open and work the accelerator pump. I also tried to start it spraying Gumout directly down the primarys while turning it over. Cdowns, I did run a new wire during the restore, I checked volatge with the key "on" at the harness going into the "BAT" terminal on the cap- I have 12.4 volts What do you think besides that - do you think I should check if its holding voltage while I am trying to start it ??? appreciate the help guys. Cypress

02-12-2006, 11:45 PM	#16
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	Re: Experienced Mechanic needs another opinion sounds like a problem with the dizzy or timing remove cap and turn over make sure rotor in turning smooth my first try would be to pull the dizzy out. and inspect bottom gear, screw-clip crap near poll piece.bad broken poll piece wire got a points dizzy to put in.or another hei to test make sure rotor is at number 1 on cap on tdc



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02-13-2006, 12:47 AM	#17
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	Re: Experienced Mechanic needs another opinion Im thinking its a fuel problem. If it ran fine one day & bad the next & you didnt change anything in between It cant hardly be a misaligned distributor or rotor. If the module went it wouldnt try to start like you said its doing. Id try a fuel filter or easier yet dump a little gas in the carb & see if it runs good for a second or two. If it does get a new pump or see if theres a carb crab. Good luck with it...corn

02-13-2006, 01:13 AM	#18
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Re: Experienced Mechanic needs another opinion You have gas fouled plugs. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

02-13-2006, 01:23 AM	#19
Rdrdave Broke and still trying Join Date: Apr 2003 Location: Alameda, CA Posts: 562	Re: Experienced Mechanic needs another opinion check condition of rotor and cap...badly cracked or broken. I had that problem. Check the simplest and go for the worse. check wiring to HEI, then cap/rotor, then firing order, then plugs and so on. You'd be amazed how many little things keep an engine from starting.

02-13-2006, 02:03 AM	#21
luisduran Registered User Join Date: Mar 2005 Location: Tinley Park Il. Posts: 144	Re: Experienced Mechanic needs another opinion SPARK PLUGS. Take one off, conect the wire and ground the plug on top of the engine and crank the engine over so you can see how much spark is going true the plug.

02-13-2006, 02:09 AM	#22
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	Re: Experienced Mechanic needs another opinion Or condensation in the cap. WD-40

02-13-2006, 02:56 AM	#23
Tropical Snowstorm Lurky lurky Join Date: Sep 2005 Location: Maryville, TN Posts: 553	Re: Experienced Mechanic needs another opinion Check for spark at the plugs. Change the plugs out (if you have some more around). Try leaving the key "on" and jumping the starter to eliminat an electrical problem while the ignition switch is at "start." You say it was running as is a few weeks ago, so that eliminates the distributor being 180 out. Gas is fresh, so that's out. The only other thing I can say is maybe the valves aren't adjusted right/too tight and are either hanging open or staying closed or something else mechanical inside the engine. Good luck with it, I hope it's something simple. __________________ Current slooooow build 1972 Cheyenne Super 1972 C10, sold thread 1970 Camaro RS Family Heirloom

02-13-2006, 04:37 AM	#24
_Dick_ PROUD TO BE A MEMBER Join Date: Sep 2005 Location: Jax Florida Posts: 234	Re: Experienced Mechanic needs another opinion if i understood you this thing sat for two years ,any one move in the exhaust system while it sat ,ie mud dobbers ,mice ,kids toys ect.

02-13-2006, 05:02 AM	#25
KFreddy Active Member Join Date: Apr 2005 Location: Miami, Florida Posts: 286	Re: Experienced Mechanic needs another opinion Check the fuel filter in the carb?

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