Brain Bucket - The 1947 - Present Chevrolet & GMC Truck Message Board Network

magwakeenercew2jh · 10-28-2008, 01:10 AM

The '83 is in with a good mechanic that says....

Wait a minute.....Here's the background....rewind....

Switched out the 305 for a mild 350. California. Hoses galore. I have to keep them all.

For the short run, the crappy 305 carb that was making the motor run seriously rich is still in. It would run nicely when it warmed up.....

Sitting in line for a burger it died. I waited 3 hrs and it started again. Figured out it was electrical. No spark at the plugs. Tried to fix the dist. No spark.

I went on line and bought a brain...I don't even know what it's called. Sits in behind the glove box in an aluminum can. They sent me the wrong one..A serious hassle to return......

So a neighbor and I pulled the "brain" and put in a non-brain distributor.

Never had the problem again.

Fast forward......Back to the carb. The truck's in the shop and the mechanic wants to get the stock distributor, rebuild the carb and get it running lean and clean.

But I'm worried that if I don't get another "brain", I'll be left high and dry again down the road.

The problem was intermittent. Only happened at the very worst times, of course.

If I get a new brain, can someone tell me what it's called and where to get it. Or tell just me I'm dangerous and to get a Prius.

grinch4om · 10-28-2008, 06:53 AM

it's a CPU and do a google search for one. You have emmisions to worry about but get it running as is and tail pipe sniff it to get some readings then try the stock distributor and the CPU and sniff again. The only thing the CPU controlled in 83 was idle emissions(a little part throttle) and spark timing. It was effective on the sniff test but didn't really help in the emmision arena. (except at idle) the cat converter did more for the air we breathe. Newer fuel control and distributorless ignition is so efficient that emmisions is reduceed because the fuel ratio is controllable from idle to WOT. use a Prius for a inner city commuter but did you know where the batteries are made in Canada, nothing grows in a 3 mile radius? How are we to recycle those huge batteries? Is it that much of an impact driving one verses say a corola? or a civic? or an Aveo?or are we just using "feel good" tactics to sell these things? South Park did a parody on them and darn if it wasn't poinent!

impalamark · 10-28-2008, 07:02 PM

I don't think you have a good answer yet so
my two cent is to leave it as is especially if you don't have any
smog test issues. the "brains" in these things are not so reliable
as you have discovered and when they fail you are on the side
of the road with your thumb out.
I have put well of 300,000 miles on these trucks and when I have
trouble I swap the distributors and tune for best mileage/driveabilty

I would not spend money to go back to an unreliable system

MArk

10-28-2008, 01:10 AM	#1
magwakeenercew2jh RAT1968 '68 Cab/'71 Parts Join Date: Feb 2002 Location: Coarsegold, CA Posts: 2,375	Brain Bucket The '83 is in with a good mechanic that says.... Wait a minute.....Here's the background....rewind.... Switched out the 305 for a mild 350. California. Hoses galore. I have to keep them all. For the short run, the crappy 305 carb that was making the motor run seriously rich is still in. It would run nicely when it warmed up..... Sitting in line for a burger it died. I waited 3 hrs and it started again. Figured out it was electrical. No spark at the plugs. Tried to fix the dist. No spark. I went on line and bought a brain...I don't even know what it's called. Sits in behind the glove box in an aluminum can. They sent me the wrong one..A serious hassle to return...... So a neighbor and I pulled the "brain" and put in a non-brain distributor. Never had the problem again. Fast forward......Back to the carb. The truck's in the shop and the mechanic wants to get the stock distributor, rebuild the carb and get it running lean and clean. But I'm worried that if I don't get another "brain", I'll be left high and dry again down the road. The problem was intermittent. Only happened at the very worst times, of course. If I get a new brain, can someone tell me what it's called and where to get it. Or tell just me I'm dangerous and to get a Prius. __________________ M17 Coarsegold, CA RAT's shiny now. But always a rat.

10-28-2008, 06:53 AM	#2
grinch4om dang its hot Join Date: Nov 2006 Location: frankfort kentucky Posts: 1,349	Re: Brain Bucket it's a CPU and do a google search for one. You have emmisions to worry about but get it running as is and tail pipe sniff it to get some readings then try the stock distributor and the CPU and sniff again. The only thing the CPU controlled in 83 was idle emissions(a little part throttle) and spark timing. It was effective on the sniff test but didn't really help in the emmision arena. (except at idle) the cat converter did more for the air we breathe. Newer fuel control and distributorless ignition is so efficient that emmisions is reduceed because the fuel ratio is controllable from idle to WOT. use a Prius for a inner city commuter but did you know where the batteries are made in Canada, nothing grows in a 3 mile radius? How are we to recycle those huge batteries? Is it that much of an impact driving one verses say a corola? or a civic? or an Aveo?or are we just using "feel good" tactics to sell these things? South Park did a parody on them and darn if it wasn't poinent! Last edited by grinch4om; 10-28-2008 at 06:54 AM.

10-28-2008, 07:02 PM	#3
impalamark Registered User Join Date: Feb 2008 Location: cocoa florida Posts: 183	Re: Brain Bucket I don't think you have a good answer yet so my two cent is to leave it as is especially if you don't have any smog test issues. the "brains" in these things are not so reliable as you have discovered and when they fail you are on the side of the road with your thumb out. I have put well of 300,000 miles on these trucks and when I have trouble I swap the distributors and tune for best mileage/driveabilty I would not spend money to go back to an unreliable system MArk __________________ the avatar was my 62 I owned for 27 years 84 chevy short short bed black 84 gmc long bed copper/ buckskin 88 chevy k5 blazer white Life's short make the most of it Mark aka impalmark Last edited by impalamark; 10-28-2008 at 07:03 PM.



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