![]() |
![]() |
#1 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Cylinder not firing
Hey guys I have a 84 K10 that the #8 cylinder is not firing.Well it is actually firing but I dont think the cylinder is getting fuel.When I start the truck all the header pipes on each cylinder get hot except #8 .I have changed plugs,plug wires,checked to see if it is getting fire and it is.checked compression on that cyl it was 145psi.Friend said it was carb (edelbrock 750 manual choke) so put on a edelbrock 750 electric choke on it ,started it up and #8 header pipe got hot but i could not get it to idle right. So got can of carb cleaner and cleaned up manual choke 750 put back on same problem.Put electric choke 750 back on and now #8 is not getting hot again. I assume since it has good compression and is getting fire it is a fuel problem,but not sure where to go from here .Please help
|
![]() |
![]() |
![]() |
#2 |
Registered User
Join Date: Jun 2011
Location: OK
Posts: 76
|
Re: Cylinder not firing
Hmm, clean your intake as well...??? Does it idle rough?
|
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
Can't be the carb. It is centrally located and feeds all cylinders. How do you its getting fire? Did you pull the cap and check inside? I'm thinkin and I'll get back if someone doesn't find it for you first.
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
#4 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
Has the truck been sitting. Can you pull the carb again and check for a mouse nest in the runner? That is if it has been sitting. How about a sticking intake valve?
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
#5 | |
Registered User
![]() Join Date: Aug 2008
Location: Clayton, NC
Posts: 55
|
Re: Cylinder not firing
Quote:
Dave
__________________
The toys shoe horned into the garage for the storms.... http://img.photobucket.com/albums/v1...2bme/SIG-2.jpg |
|
![]() |
![]() |
![]() |
#6 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Re: Cylinder not firing
no i have not cleaned the intake. it does idle fine.i have started to pull the valve cover and look around but i have not got that far yet.when you rev the motor it does pop some thru the carb
|
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
POPPIN THROUGH THE CARB!! We've been here before. Pull that cover and check the intake valve and associated valve train.
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Re: Cylinder not firing
also the truck has a fuel cell in the bed because the gas tank had a hole rusted in it so i just stuck a fuel cell in it but he seal around the lid must be bad because i got water in the fuel cell.the truck ran great before this happened.so i drained all the fuel blew out fuel line and changed the filter and have had this problem every since then could that have anything to do with it.
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
Read this 72Tealnwhite had a similar experience.
http://67-72chevytrucks.com/vboard/s...d.php?t=471111
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Re: Cylinder not firing
well i pulled the valve cover off and it looks like the pushrod is bent on the exhaust valve.when it is running it looks like the pushrod is wobbling around. what could have caused this to happen?
|
![]() |
![]() |
![]() |
#11 |
Registered User
Join Date: Jul 2010
Location: Lafayette, IN
Posts: 621
|
Re: Cylinder not firing
A stuck valve, carbon buildup in the chamber, soft pushrod (not likely). I would pull the heads and have them hot tanked and magnafluxed. That can usually be done for less than $75 bucks.
|
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
Don't forget to let us know how you fix it!!
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
#13 | |
Registered User
Join Date: Apr 2011
Location: corpus christi, tx - america's fattest city
Posts: 253
|
![]() Quote:
The long block assembly is a precision machine, and when all is in harmony the engine wears evenly as it's been running. Depending on the age of the engine you may want to consider a rebuild. A reconditioned head will mean an increase in compression for the cylinders on that side, and the rings may not like it and tell you so by blowing by. |
|
![]() |
![]() |
![]() |
#14 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Re: Cylinder not firing
the motor in the truck was built about 10 years ago and probably only has about 7500 miles on it .It has never been abused or overheated and was built with quality parts. brand new 4 bolt main block from scoggins dickey,brand new world products sportsman cylinder heads,speed pro forged pistons, comp cams cam,lifters,pushrods,roller rockers only thing not brand new was crank and connecting rods.I am having a hard time swallowing the pill as to why this has happened
|
![]() |
![]() |
![]() |
#15 |
Registered User
Join Date: Dec 2008
Location: Strawplains,Tenn
Posts: 16
|
Re: Cylinder not firing
well i pulled pushrod and it is not bent ,put it back in adjusted valve,started truck and noticed the intake valve on #6 was barely moving ,#8 intake valve was moving a little more than #6 and #8 exhaust valve is barely moving so i am now thinking camshaft has gone bad. i dont think it is lifters collapsed because they are not making any noise.
|
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Dec 2010
Location: Pittsburgh, PA
Posts: 1,009
|
Re: Cylinder not firing
If the cam wasn't broken in properly when the engine was rebuilt, you could have unevenly worn down the cam lobes. I'm betting that's what happened if your symptoms are as you describe. That's why I became weary of buying someone else's project. I've had both good and bad luck with it.
__________________
Steve Member of the Foot Pedal Club '83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL, Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws, 350 HP 350 crate engine from Jegs, Turbo 400 ![]() |
![]() |
![]() |
![]() |
#17 |
Registered User
![]() Join Date: Dec 2008
Location: indiana
Posts: 304
|
Re: Cylinder not firing
I would point my finger at the 7500 miles in 10 years of use as the problem. That would leave plenty of time between uses to allow the oil to drain off the cam and bleed off the lifters and cause uneven wear on the cam lobes.
__________________
00' Z28 ("wifes" car) 92' Mustang w/sbc ![]() 87' GMC Sierra Classic Short Bed Fleet side almost stock 69' Chevy short step carbed 6.0 w/400th trans. Completed w/325 miles on it |
![]() |
![]() |
![]() |
#18 |
Registered User
Join Date: Mar 2009
Location: Sioux Falls, SD
Posts: 44
|
Re: Cylinder not firing
i agree with the cam, i had a comp that only had about 500 miles on it when it started missing. pulled the cam out sure enough one lobe was completely ground off, comp said it was a bad grind...
|
![]() |
![]() |
![]() |
#19 |
Registered User
Join Date: Jun 2011
Location: Richmond,Va
Posts: 2,934
|
Re: Cylinder not firing
I agree with them. Probrably started with improper break in from the builder.
__________________
Nick Carter 1967 C10 Short bed Fleetside Project Cheap Thrills! 2WD C10 Modern/Performance Alignments Easiest Alignment Ever! |
![]() |
![]() |
![]() |
Bookmarks |
|
|