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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: wired1141 on August 10, 2014, 08:05:51 pm

Title: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 10, 2014, 08:05:51 pm
I have a 79 SWB with a 50K mile 350 engine and a 350 turbo trans that started cutting out at hwy speeds. I have replaced the coil and the module with new ones but still have the same trouble. Could it be the fuel pump? I checked the ohms on the pickup coil and it showed good at 863 ohms and the book I have showed 500 to 1500 ohms is good. I have a new Edelbrock 1406 carb so I know that's not the problem. I sure need some help thank you 
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 10, 2014, 09:08:28 pm
The ohm test didn't make sense to me due to it is not running so that only checks the coil not the magnetic portion that the coils work with so am I stupid or should I replace the pickup coil? I'm lost.
Title: Re: 79 350 Chevy cuts out on hwy
Post by: thefarmboy21 on August 11, 2014, 08:50:29 am
Well a fuel pump and new fuel filter shouldn't run you more than $25 so I'd do that regardless. Sounds like it could be a loose wire somewhere. Take your module out and have it tested too.....you may even find a bad connection in process.
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 12, 2014, 11:03:06 pm
does it do it when you take off hard?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 14, 2014, 06:27:29 pm
yes sometimes it does
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 14, 2014, 10:39:50 pm
what about your fuel filter?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 15, 2014, 11:49:00 am
Its new
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 15, 2014, 11:06:30 pm
the cut out i would think would be a fuel issue. i would put a fuel pressure gauge on it and see what its reading at idle and cruising then when it cuts out. something else the vacuum advance might be sticking or broke and causing the wrong timing. see how well the weights move and look
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 17, 2014, 03:09:02 pm
fuel pressure is good but the weights are kind of sticky, would it be ok to use wd-40 on it to free it up?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 18, 2014, 09:54:19 am
Wd40 can coat the electronics and cause them to overheat.is the pressure good when it starts to act up?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 18, 2014, 03:46:43 pm
Pressure is always good, how does a 350 run if the pickup coil is going out? 
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 18, 2014, 09:33:13 pm
Never had one kind of go out. Mine always either didn't work or stop working once hot
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 23, 2014, 05:00:14 pm
Now its cutting out at all driving ranges. I am thinking the pick up coil but I have always thought like you said, pick up coil works or it doesn't. Everything on the distributor is new other than the pick up coil and the weights and the engine has 30K on it. I am thinking it's still in the distributor but I am lost. Now when I rev it up it cuts out around 10k rpms but idles perfect and up to that point. Any guess?     
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 23, 2014, 05:11:40 pm
10k??? You can replace a distributor for under 50 on ebay
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 23, 2014, 05:48:42 pm
Yes it cuts out now after 10k rpms, do you have a link for distributor?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 23, 2014, 05:57:04 pm
Why you pushing 10k. On my phone but it you search on here for distributor eBay you will find it
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 23, 2014, 05:58:17 pm
http://forum.73-87chevytrucks.com/smforum/index.php?topic=28795.msg240354#msg240354
Here's a couple different ones
Title: Re: 79 350 Chevy cuts out on hwy
Post by: bd on August 23, 2014, 08:05:43 pm
Pickup coils can fail intermittently.  In fact, it's a rather common scenario.

1,000 RPM huh?

Super 65kv HEI Distributor (http://www.ebay.com/itm/SBC-BBC-CHEVY-350-383-SUPER-65K-HEI-DISTRIBUTOR-6500-R-/351066394428?pt=Motors_Car_Truck_Parts_Accessories&hash=item51bd300f3c&vxp=mtr)
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 23, 2014, 09:16:57 pm
I don't know bd that ones only good for 7k
Title: Re: 79 350 Chevy cuts out on hwy
Post by: 79K10Crusher on August 28, 2014, 09:39:23 pm
Plugs and wires changed lately?  Simple stuff is usually what it is....
Title: Re: 79 350 Chevy cuts out on hwy
Post by: wired1141 on August 29, 2014, 07:34:12 pm
Finally had time to fix it, it was the pick up coil. THANKS for all the input it was a lot I needed to learn. 
Title: Re: 79 350 Chevy cuts out on hwy
Post by: Irish_Alley on August 29, 2014, 10:58:30 pm
glad you got her figured out. maybe i need to replace my coil on my 94. wonder if it was a bad connection on the coil?
Title: Re: 79 350 Chevy cuts out on hwy
Post by: FearNoMan78k10 on August 30, 2014, 12:26:22 am
Sounds like it is a possibly that's for sure.... Hmmm... Yeah you should look into the coil... Distributor... See if you can come up with something?  I'm feeling inside like your on the right track there Irish ...
Title: Re: 79 350 Chevy cuts out on hwy
Post by: 78BIG-TEN on August 30, 2014, 01:22:39 pm
you must mean 1000 rpm what about spark plugs.they could be glazed