HEI Ignition Problem

[neba]

i would try installing a clear plastic in line gas filter so you can see if your getting fuel

[nrb's70gmc]

i have been asking alot of people and they are telling me it sounds more like a fuel problem (because the truck does start right up) but as you know these old tanks are rough on the motors

(i use two fram G3's) but latly i have been fueling up at a 1/4 tank or a little below. i always used to fill up at 1/2 tank- regardless every time i changed a filter it looked like coffee coming out of the old one's.

i use two filters because it seems like a good idea with an old tank ( i place 1 on the fuel line about 3ft out of the tank and then the 2nd one up by the carb.
cant wait untill i get an aluminum under bed tank

[highperf4x4]

Sounds to me like your sock inside the tank is shot, probably falling apart and clogging up your fuel line. From what you're telling us today I would say it's a fuel problem hands down.

I would pull the whole pickup/sending unit out of the tank and check it out.

[nrb's70gmc]

Originally Posted by highperf4x4

Sounds to me like your sock inside the tank is shot, probably falling apart and clogging up your fuel line. From what you're telling us today I would say it's a fuel problem hands down.

I would pull the whole pickup/sending unit out of the tank and check it out.

Thanks man, for the info
is the sock in the tank like a universal thing i could buy at a auto parts store?
i know what is (dont get me wrong) but if i have to replace it, whare can i get one on short notice?

[highperf4x4]

Nope. I couldn't find a replacement at a local parts store. You could take one with the right shape and make it work with a piece of hose to attach it maybe if it's only temporary.

[nrb's70gmc]

Originally Posted by highperf4x4

Nope. I couldn't find a replacement at a local parts store. You could take one with the right shape and make it work with a piece of hose to attach it maybe if it's only temporary.

what do you mean? so do they sell any at the local auto shops? just not one for our trucks?

[highperf4x4]

Correct.

[nrb's70gmc]

ok thanks

[highperf4x4]

you're welcome

[nrb's70gmc]

I will update again tomarrow with my findings (and questions)

[highperf4x4]

we will be here.

[nrb's70gmc]

one more quick fact---i now have a new cap,rotor,pick up coil, and i had both my ignition modules tested (both good) and this problem is still happining.

but i have to say i needed a new cap (for sure) because the other one was chipped/cracked ware the carbon brush sticks though the underside,

[nrb's70gmc]

If the screen/sock inside my tank needs to be replaced ware can i get a new one? BROTHERS/CLASSIC INDUSTRIES/LMC/CLASSIC PARTS OF AMERICA?????? lol i have all the catalogs.

the auto parts stores dont sell them (i confirmed today)

[highperf4x4]

If you have all the catalogs then why do you need our input?

[nrb's70gmc]

well i looked though brothers and did not see any gas tank socks/screens
just wondering if anyone has had to replace one before.

[1-PU70]

Well I have been following this and for what its worth here is what I think. Even though you had the modules tested that doesn't mean they are good. I have had bad ones test good. This problem sounds exactly like a bade module. And as fare as using 2 fuel filters some might disagree maybe everyone but you never run a fuel filter before a mechanical fuel pump and you never run a fuel filter after an electric pump. Good luck.

[nrb's70gmc]

ya i have had modules go bad also thats why i thught this problem was a the ignition--but im going to change the fuel filters and test drive it after it stops snowing--before i buy anything else.

[72swb_327stroker_?]

If you can try just one filter.... do so, two might be starving the carb.

I think this is more fuel related, But like I mentioned earlier... the module is usually the culprit here.

Can you check the fuel pressure with a gauge? You would need to check the pressure at the carb inlet. also...might wanna bump up a jet size too.

[nrb's70gmc]

i really have never had a problem with the filters or carb jetting issues before but if both filters pluged up than that would mean the filters are starving the engine (just common sense)

[highperf4x4]

Originally Posted by 1-PU70

And as fare as using 2 fuel filters some might disagree maybe everyone but you never run a fuel filter before a mechanical fuel pump and you never run a fuel filter after an electric pump. Good luck.

Did you get that backwards?

Actually a mechanical pump pulls really well and an electric pump pushes really well. It's the electric pump that has trouble pulling. That's why the majority of them are inside the gas tank. It would be impossible not to have the filter "after" a pump that's inside the tank. Even the factory electric pumps that are located outside the tank like the ones on my shop vans have a 2nd primer pump inside the tank to push the fuel to the pressure pump.

[highperf4x4]

Originally Posted by nrb's70gmc

well i looked though brothers and did not see any gas tank socks/screens
just wondering if anyone has had to replace one before.

http://www.classicparts.com/1967-87-...ctinfo/23-598/

Or you can just go to www.classicparts.com and do a search for "fuel sock"

[nrb's70gmc]

Originally Posted by highperf4x4

http://www.classicparts.com/1967-87-...ctinfo/23-598/

Or you can just go to www.classicparts.com and do a search for "fuel sock"

hay thank for the link man, just a quick question. if the fuel sock happens to be intact--i guess it can still get plugged up over ther years and still may need to be replaced correct?

[El Jay]

Going back to spark plugs; I run Accel shorties too.
Mike's Bump & Grind Garage shipped a set to my front door for about $25 last year.

[bigguy69]

i have had a tach wire come loose and ground out, it caused about the same problems you are talking about.

[highperf4x4]

Originally Posted by nrb's70gmc

hay thank for the link man, just a quick question. if the fuel sock happens to be intact--i guess it can still get plugged up over ther years and still may need to be replaced correct?

Unelss someone has replaced that sock it will be shot by now. When you tell me that you're getting stuff out of your fuel filters that looks like coffee grinds then I'm sure it has already started coming apart. It will probably crumble in your hand. You will be able to tell if it's still flexible and fairly clean as soon as you pull it out. If it needs to be replaced then your filters probably do too.