engine dies in 15 minutes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

happy1970GMC · 02-14-2016, 04:27 PM

1970 GMC probably a '72 engine, 350, Q jet, auto tranny. Just replaced the mechanical fuel pump. It still dies at 13 to 15 minutes, and it will have to cool down for at least an hour, then do it again. Any help would be appreciated.

**68350** · 02-14-2016, 04:38 PM

What does it have to cool down for an hour? Will it not restart or?

happy1970GMC · 02-14-2016, 04:59 PM

It will turn over, but not fire. I've checked the gas cap, no vacuum in the tank. Just replaced the fuel pump, I can pull on the throttle and squirt fuel in the carb.

**68350** · 02-14-2016, 05:32 PM

Do you have an HEI distributor? Almost sounds like the control module or something is bad and when it gets heated up, it's causing the truck to die. Another thought I had was the motor is running too rich and maybe flooding itself out? Are your spark plugs wet?

Ed F · 02-14-2016, 05:57 PM

Sounds like it could be a plugged fuel filter to me

Ken O. · 02-14-2016, 06:08 PM

Just had the same thing on my 67 GMC. It had the points distributor on it. After it ran for a while, 10-15 min it would die, then not start again, Wait an hour and it would fire up and again after 10-15 min it would do the same thing again. I went through EVERYTHING and finally put a new HEI distributor in it and it runs perfect now, no issues in 2 months.

davepl · 02-14-2016, 06:22 PM

The HEI modules can get flaky when hot - if you have a spare distributor, that'd be my guess. My first guess was tank venting, but you said no vacuum, so HEI it is!

happy1970GMC · 02-15-2016, 12:52 AM

Thanks for the ideas, I'll get back to it next weekend.

87Skier · 02-15-2016, 01:03 AM

Had a 1990 Suburban do the same thing. Just needed new cap/rotor, plugs, and wires. Ran perfect after that. Check that distributor too.

swamp rat · 02-15-2016, 02:18 AM

Something else, there is a short rubber hose below the tank, if its getting old and rotted it can collapse and restrict fuel flow, that includes any rubber line between the tank and pump, make sure its actual fuel line that is reinforced and not non reinforced rubber hose...

Check the filter like previously mentioned, try and back flow it with some air and see if there are any fine white chards of material in it, if there is that is the pickup sock deteriorating, time to replace the pickup screen.

Davidf · 02-15-2016, 11:07 AM

+1 on ignition related components failing after heating up. Not too long ago, I purchased 64 Corvair and installed all new ignition parts. A mile or so down the road and it stop dead in its tracks. I decided to replace the points, condenser and ignition coil again...all was well the second time around. So, BOOB (Bad Out Of Box) parts are not uncommon.

zeldman · 02-15-2016, 11:12 AM

If it is the old points and condenser distributor, sounds like the coil is breaking down. To test it, remove it, then shake it, If it makes a sloshing noise replace it.

Could be the same for HEI.

happy1970GMC · 02-15-2016, 01:36 PM

Thanks for the ideas, I'll check them out.

**praisegeetarman** · 02-15-2016, 05:06 PM

Check that the fuel tank is venting. If you remove the gas cap and the problem goes away, then that's what it is.

rripp · 02-15-2016, 06:18 PM

I would bet its the coil.

snipescastle2 · 02-15-2016, 08:05 PM

Also, if you replaced the hei module recently and didn't use the dielectric grease,the module will fry to a crisp.... just sayin'
Ben

davepl · 02-15-2016, 08:11 PM

Quote:

Originally Posted by praisegeetarman

Check that the fuel tank is venting. If you remove the gas cap and the problem goes away, then that's what it is.

He said no vacuum in the tank in his initial description.

kilrcady · 02-15-2016, 09:10 PM

fuel filter

**71CHEVYSHORTBED402** · 02-16-2016, 12:43 AM

Tank vent > fuel filter > distributor.................More likely distributor than fuel filter, but a filter is cheap and easy. If all that fails, I'd replace all fuel lines, including the vent line. If that fails, couldn't tell ya.

Don't know if that could be a fuel pump. Seems it would work or it doesn't.

snipescastle2 · 02-16-2016, 12:02 PM

Just something to check, but is there any fuel coming out the "Weep Hole" by chance? might want to make sure you have no fuel getting into your oil pan also....
Ben

happy1970GMC · 02-21-2016, 01:08 AM

Hello to anyone reading this, I put a new coil in today and doubled my run time. Now it will run for about 30 minutes. I bought a remote starter, but haven't figured how to hook it up, the directions are for a more modern vehicle. Can a part store test my module for me?

EARNHARDT#3 · 02-21-2016, 05:44 AM

Quote:

Originally Posted by happy1970GMC

Hello to anyone reading this, I put a new coil in today and doubled my run time. Now it will run for about 30 minutes. I bought a remote starter, but haven't figured how to hook it up, the directions are for a more modern vehicle. Can a part store test my module for me?

I don't think so. They sure can sell you a Chinese one that won't last either though. I have a stash of GM ones incase I ever need them. Go to the JY and grab a few if you can. Around here you won't really find anything that old but maybe you have a yard with older stuff nearby.

**Grumpy old man** · 02-21-2016, 11:36 AM

I still say it's a fuel issue , The dist ,coil,capacitor ,and anything else wouldn't continue to start multiple times and just run for 13-15 minutes ,It would have completely failed already .

Dirty fuel pick up in tank
Fuel line between tank and hardline under cab collapsing / cracked
Inline fuel filter
Bronze fuel filter in carb

it starts ,runs until crud in fuel line restricts flow .Won't restart ,wait an hour fuel flows back clearing line and restarts .Dies if 13-15 minutes . Why no pictures ? a good look at the condition of the rest of the engine/fuel lines and ignition could let someone give a further diagnosis .have you tried starting it once it dies using carb cleaner to see if it will fire even for a few seconds ?

**Grumpy old man** · 02-21-2016, 11:46 AM

I just red back thru your threads ,You've been dealing with this issue since 6/2012 ? Take it to your local mechanic .

http://67-72chevytrucks.com/vboard/s...d.php?t=528601

http://67-72chevytrucks.com/vboard/s...d.php?t=529028

http://67-72chevytrucks.com/vboard/s...d.php?t=534240

Gromit · 02-21-2016, 12:06 PM

"I bought a remote starter, but haven't figured how to hook it up, the directions are for a more modern vehicle".

If you bought the Actron Remote Starter I believe it is in the instructions (Figure 5) - (see attached pdf)

Re using the remote starter I found it more convenient to just install a permanent 12 gauge wire from that "S" lug on the solenoid up to an insulated lug (really just a 1/4"-20 x 1" bolt through a chunk of plastic) mounted on the inside passenger side fender well next to the factory distribution block - then you can hook up the remote starter wires - one to that bolt and the other to your positive on the battery - without having to thread the leads through the headers and into the cramped space around the solenoid where it is easy to short against the positive cable.

Always turn your key to the run position before activating a remote starter (as advised in most repair manuals)..

02-14-2016, 04:27 PM	#1
happy1970GMC Registered User Join Date: Apr 2012 Location: Longmont, CO Posts: 31	engine dies in 15 minutes 1970 GMC probably a '72 engine, 350, Q jet, auto tranny. Just replaced the mechanical fuel pump. It still dies at 13 to 15 minutes, and it will have to cool down for at least an hour, then do it again. Any help would be appreciated.

02-14-2016, 04:38 PM	#2
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: engine dies in 15 minutes What does it have to cool down for an hour? Will it not restart or? __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-14-2016, 05:32 PM	#4
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: engine dies in 15 minutes Do you have an HEI distributor? Almost sounds like the control module or something is bad and when it gets heated up, it's causing the truck to die. Another thought I had was the motor is running too rich and maybe flooding itself out? Are your spark plugs wet? __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-14-2016, 05:57 PM	#5
Ed F Registered User Join Date: Dec 2015 Location: Holland Mi. Posts: 302	Re: engine dies in 15 minutes Sounds like it could be a plugged fuel filter to me

02-14-2016, 06:08 PM	#6
Ken O. Registered User Join Date: Jan 2016 Location: Spokane WA Posts: 106	Re: engine dies in 15 minutes Just had the same thing on my 67 GMC. It had the points distributor on it. After it ran for a while, 10-15 min it would die, then not start again, Wait an hour and it would fire up and again after 10-15 min it would do the same thing again. I went through EVERYTHING and finally put a new HEI distributor in it and it runs perfect now, no issues in 2 months.

02-14-2016, 04:59 PM	#3
happy1970GMC Registered User Join Date: Apr 2012 Location: Longmont, CO Posts: 31	Re: engine dies in 15 minutes It will turn over, but not fire. I've checked the gas cap, no vacuum in the tank. Just replaced the fuel pump, I can pull on the throttle and squirt fuel in the carb.

02-14-2016, 06:22 PM	#7
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: engine dies in 15 minutes The HEI modules can get flaky when hot - if you have a spare distributor, that'd be my guess. My first guess was tank venting, but you said no vacuum, so HEI it is! __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

02-15-2016, 12:52 AM	#8
happy1970GMC Registered User Join Date: Apr 2012 Location: Longmont, CO Posts: 31	Re: engine dies in 15 minutes Thanks for the ideas, I'll get back to it next weekend.

02-15-2016, 01:03 AM	#9
87Skier Registered User Join Date: Mar 2014 Location: Corvallis, OR Posts: 711	Re: engine dies in 15 minutes Had a 1990 Suburban do the same thing. Just needed new cap/rotor, plugs, and wires. Ran perfect after that. Check that distributor too. __________________ 1972 GMC Jimmy Custom 4.8L (L20)/6L90E/NP205 1989 Chevy Suburban V2500 350/Turbo 400/4.11 gears 1996 Chevy Suburban K1500 350/4L60E

02-15-2016, 02:18 AM	#10
swamp rat Registered User Join Date: Oct 2007 Location: Spanaway Posts: 8,451	Re: engine dies in 15 minutes Something else, there is a short rubber hose below the tank, if its getting old and rotted it can collapse and restrict fuel flow, that includes any rubber line between the tank and pump, make sure its actual fuel line that is reinforced and not non reinforced rubber hose... Check the filter like previously mentioned, try and back flow it with some air and see if there are any fine white chards of material in it, if there is that is the pickup sock deteriorating, time to replace the pickup screen. __________________ Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's

02-15-2016, 11:07 AM	#11
Davidf Registered User Join Date: Nov 2014 Location: Austin Posts: 749	Re: engine dies in 15 minutes +1 on ignition related components failing after heating up. Not too long ago, I purchased 64 Corvair and installed all new ignition parts. A mile or so down the road and it stop dead in its tracks. I decided to replace the points, condenser and ignition coil again...all was well the second time around. So, BOOB (Bad Out Of Box) parts are not uncommon.

02-15-2016, 11:12 AM	#12
zeldman Registered User Join Date: Oct 2013 Location: Rt 66 Gallup, NM Posts: 527	Re: engine dies in 15 minutes If it is the old points and condenser distributor, sounds like the coil is breaking down. To test it, remove it, then shake it, If it makes a sloshing noise replace it. Could be the same for HEI. __________________ 2005 GMC K2500HD D/A 1993 GMC K1500 2011 Subaru Legacy. 2013 Subaru Outback 1970 C-10 2WD, SWB stepside, 292, TH350, PS, more rust than anything. God is my pilot.

02-15-2016, 01:36 PM	#13
happy1970GMC Registered User Join Date: Apr 2012 Location: Longmont, CO Posts: 31	Re: engine dies in 15 minutes Thanks for the ideas, I'll check them out.

02-15-2016, 05:06 PM	#14
praisegeetarman Senior Member Join Date: Feb 2010 Location: Harrah, Washington Posts: 323	Re: engine dies in 15 minutes Check that the fuel tank is venting. If you remove the gas cap and the problem goes away, then that's what it is. __________________ 71 Blazer 4X4 (unmolested, all original (including paint) 74,000 mile barn find) 67 Camaro RS SS (unmolested, all original (including paint) 81,000 mile barn find) Keith Riel

02-15-2016, 06:18 PM	#15
rripp Registered User Join Date: May 2012 Location: Farmington MO Posts: 78	Re: engine dies in 15 minutes I would bet its the coil.



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02-15-2016, 08:05 PM	#16
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: engine dies in 15 minutes Also, if you replaced the hei module recently and didn't use the dielectric grease,the module will fry to a crisp.... just sayin' Ben

02-15-2016, 09:10 PM	#18
kilrcady Registered User Join Date: Sep 2015 Location: central NJ Posts: 102	Re: engine dies in 15 minutes fuel filter

02-16-2016, 12:43 AM	#19
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,118	Re: engine dies in 15 minutes Tank vent > fuel filter > distributor.................More likely distributor than fuel filter, but a filter is cheap and easy. If all that fails, I'd replace all fuel lines, including the vent line. If that fails, couldn't tell ya. Don't know if that could be a fuel pump. Seems it would work or it doesn't. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

02-16-2016, 12:02 PM	#20
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: engine dies in 15 minutes Just something to check, but is there any fuel coming out the "Weep Hole" by chance? might want to make sure you have no fuel getting into your oil pan also.... Ben

02-21-2016, 01:08 AM	#21
happy1970GMC Registered User Join Date: Apr 2012 Location: Longmont, CO Posts: 31	Re: engine dies in 15 minutes Hello to anyone reading this, I put a new coil in today and doubled my run time. Now it will run for about 30 minutes. I bought a remote starter, but haven't figured how to hook it up, the directions are for a more modern vehicle. Can a part store test my module for me?

02-21-2016, 11:36 AM	#23
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: engine dies in 15 minutes I still say it's a fuel issue , The dist ,coil,capacitor ,and anything else wouldn't continue to start multiple times and just run for 13-15 minutes ,It would have completely failed already . Dirty fuel pick up in tank Fuel line between tank and hardline under cab collapsing / cracked Inline fuel filter Bronze fuel filter in carb it starts ,runs until crud in fuel line restricts flow .Won't restart ,wait an hour fuel flows back clearing line and restarts .Dies if 13-15 minutes . Why no pictures ? a good look at the condition of the rest of the engine/fuel lines and ignition could let someone give a further diagnosis .have you tried starting it once it dies using carb cleaner to see if it will fire even for a few seconds ?

02-21-2016, 11:46 AM	#24
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: engine dies in 15 minutes I just red back thru your threads ,You've been dealing with this issue since 6/2012 ? Take it to your local mechanic . http://67-72chevytrucks.com/vboard/s...d.php?t=528601 http://67-72chevytrucks.com/vboard/s...d.php?t=529028 http://67-72chevytrucks.com/vboard/s...d.php?t=534240 Last edited by Grumpy old man; 02-21-2016 at 11:54 AM.

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