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Old 04-06-2013, 10:38 PM   #1
JJorgensen52
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Intermittent ignition issues?

Quote:
Originally Posted by JJorgensen52
Driving my '72 tonight, I had some stumbling and then died - thought it was out of gas, added 8 gallons to the tank and tried again - occasional coughs but no luck. Flat towed it the mile back to my street, which is a big hill - rolled down it, tried to pop start it (figuring maybe a weak battery) - it caught and ran, but really poorly and died under any load.

Fuel system problem, or???

Also had a muffler explosion ... so much for my new exhaust
Okay, I've considered this a bit and I'll add some new info:

Truck ran fine last week and I drove it around a bit in the drive earlier today. Last weekend I set the timing to 6*BTDC (the emissions sticker calls for 4* but I've always used 8* as a rule of thumb and it ran better at 6*). I drove it roughly 40 miles after that at a variety of speeds and all was well.

Tonight, I went to drive down to the gas station and it was stumbling a bit when it was first started, but then it was fine, then it would stumble again. I made it 3/4 of a mile and it died on the side of the road. I assumed it was out of gas.

Little while later, 8 gallons in the tank, still won't start, even with a bit of fuel in the carb. It occasionally would cough, was backfiring in the exhaust and the carb a bit.

Decided to just flat tow it home - going down my street, which is a hill, I dropped it in second to see if I could roll start it. Roll start it did, which is unfortunate because all the cranking meant my muffler was full of fuel and exploded. It ran for maybe 25 seconds, sputter, stall.

Haven't tried to restart. I'm wanting to rule out the timing as an issue because it hasn't moved since I just set it. I was thinking fuel, acted like it was out of gas - but clearly my muffler indicates that it's getting fuel. It is sparking, since it will run sometimes.

Am I looking at points / condensor / coil problems, or is something mechanically amiss?
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Last edited by JJorgensen52; 04-07-2013 at 01:11 AM.
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Old 04-07-2013, 11:35 AM   #2
JJorgensen52
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Re: Intermittent ignition issues?

Anyone?
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CURRENT
'50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build
'63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos
'66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos
'69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!)
'72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh
'99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily)
'99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs)
SOLD
'71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder)
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Old 04-07-2013, 11:56 AM   #3
Ol Blue K20
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Re: Intermittent ignition issues?

anyone of those would cause this. it's most likely in the ign, I would start with the points and cond.
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Old 04-07-2013, 01:17 PM   #4
JJorgensen52
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Re: Intermittent ignition issues?

So, after tinkering with it a bit:

Points were clean and properly adjusted, condensor is new, coil is fine.

However, the points assembly screw (the one that grounds it to the distributor) was loose... wa-la! Fired right up. Go figure.
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CURRENT
'50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build
'63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos
'66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos
'69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!)
'72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh
'99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily)
'99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs)
SOLD
'71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder)
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Old 04-07-2013, 01:27 PM   #5
ole dollor
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Re: Intermittent ignition issues?

its the little things that are the hardest to track down....glad you got it fixed..now you can take it out and have fun.
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