Exhaust/valve tick

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
I recall the valve adjustment to make the EfE stop leaking?

I would do it again now...that's likely a good place to start. :p
Ha huh? Valves are good. Truck lost consistent idle after they fixed the exhaust leak but he put the efe back on and now the flap actuates well enough that the spring tries to keep it in a particular position. Asking what that is

Sent from my SM-G965U using Tapatalk
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
I recall the valve adjustment to make the EfE stop leaking?

I would do it again now...that's likely a good place to start. [emoji14]

I want to say when the thermal vacuum switch on the thermostat housing operates the valve, it is pulling it closed. Exhaust gas flow would force it open by default.
By the way what time zone u in? Lol you seem to always be on. Thanks for that too! Ha

Sent from my SM-G965U using Tapatalk
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
Ok, so the spring tries to keep it closed and the exhuast should be enough to overcome that. Which means I need to tie that bad boy off against the spring tension. That's what I expected

Sent from my SM-G965U using Tapatalk
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,134
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
Yes that sounds correct, against the spring tension.
Pictures would be helpful but it seems that we are managing pretty well without them?

Central Standard Time, I live in Oklahoma City and work nights. ;)

I have a very good faith that the hawks present within the bounds of this MSB are very eagerly awaiting the first available opportunity to POUNCE and correct any information given should I say something wrong. Many others know much better than I, rest assured...like you said MAX, i'm only "always on" because they are asleep like normal folk, so I get to answer first.
 
Last edited:

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,917
Reaction score
4,116
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Go back to post #7 on page 1 and look at the EFE valve. If your valve is like the one on my '85 454 with no vacuum applied, the valve is open. My truck is currently getting a new engine and I can verify the valve is open with no vacuum. I'm not sure if your set up is similar.

It's been 35 years since I've had a vehicle with the old bi-metal type heat riser. I believe those are closed until the spring heats up enough, then the valve is open. On my '64 Chevelle I had back then, I wired it open as it sounded like an exhaust rain cap on a semi.

The '85 system is reliant on all of the vacuum lines, check valves and ported vacuum switches working correctly. If there are any vacuum leaks, it can cause poor performance. Due to the fact I have to go through California's bi-annual smog program, everything has to work on my truck. I have replaced every vacuum operated engine part on my truck, even the vacuum motor in the air cleaner snorkel. I also found during this rebuild process that both my secondary vacuum pods on the passenger side of he carb were bad. I had to replace all of the vacuum lines since all the OEM molded connectors were dry rotted. As you can see from my emissions label, there's a lot of places to have a problem. One thing to check also is make sure the check valves are facing in the correct direction. Many are one way valves.

You must be registered for see images attach
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
Yes, mine looks like the one on post 7. But if you look up by the actuating rods, youll see you are looking straight down on the actuator plate (looks like a 7). While in that position, the valve shows open. So I wired mine against the spring tension so that plate was in line with the pipe (like is shown in your picture). Seems to be running better and not pushing and pulling me when I drive like it was.
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
Update - had them pull the heat riser and miscommunication led them putting it back on with new donut gaskets instead of replacing with a new freaking pipe. Either way, that was the bulk of my tick. The rest was slightly loose manifold bolts and manifold to down pipe flange bolts. Tighten those up with a 9/16 and voila! Hope this helps someone.

Also the push and pull I felt was because I had crappy wires that were too thin and not separated well enough from each other or other metal causing spark jump. Another issue was my dizzy wasn't hooked up to an actual manifold source (holy cow was that an upgrade!) And last off, I used some hemostats to back out my secondary throttle blade screw a touch.

Don't be surprised to see that second paragraph a few other places since I've bitched and moaned about my truck running poorly after all my work and ignorance! Thanks again to all who've helped! If in doubt, assume you're wrong and check everything again!

Sent from my SM-G965U using Tapatalk
 

TROY TUCKER

Junior Member
Joined
Apr 21, 2019
Posts
1
Reaction score
0
Location
star city ar. 71667
First Name
troy
Truck Year
1984
Truck Model
C10 silverado
Engine Size
5.0
I'm needing to replace the gasket for the EFE ON A 1984 5.0 C10, but haven't had any luck in getting the right gasket. I think they keep giving me a gasket for a 5.7. Would any of you guys know the part # for the 5.0 gasket?
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
Do you actually want a gasket? Does your heat riser still serve a function? If not - pay an extra $20 and have a muffler shop replace it with tubing and forget about it.... It's function was intended for warm up and choke like applications. I'm like you and appreciate the stock functions of these machines but the heat riser is not the hill to die on.

Sent from my SM-G965U using Tapatalk
 

maxtwms

Full Access Member
Joined
Jan 29, 2014
Posts
170
Reaction score
33
Location
Alabama
First Name
Max
Truck Year
1985
Truck Model
K10
Engine Size
305
If you do actually NEED the gasket, NAPA never fails

Sent from my SM-G965U using Tapatalk
 

Forum statistics

Threads
44,168
Posts
950,799
Members
36,284
Latest member
RogerioHR
Top