![]() |
![]() |
#26 |
Registered User
![]() Join Date: Sep 2001
Location: Fort Wayne, Indiana, USA
Posts: 1,887
|
Re: engine popping at wot
The WOT problem does sound like ignition components. Under low-load conditions the ignition flaw is not apparent however under high-load (WOT) conditions ignition problems become exaggerated.
|
![]() |
![]() |
![]() |
#27 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
ok yeah ill look into it some more do you think i should replace my distributor cap? ive never replaced it since ive had my truck. ill pull my plugs and replace them tonight
|
![]() |
![]() |
![]() |
#28 |
is Certifiable
Join Date: Feb 2008
Location: Hinesville, Georgia
Posts: 160
|
Re: engine popping at wot
I have the manual choke version of the 600 on my truck, with the choke removed. I do need to adjust the mixture screws thru the year, as the season change. When its rich it gets sluggish when its hot. And when its lean it skips and misses under hard acceleration and WOT. I wouldn't buy any parts yet. Pull the plugs so you can see what is going on. I would put my money on the timing being a bit off, and it being to lean.
__________________
1972 Chevy C10 LWB 350 Auto Blue with a white roof. |
![]() |
![]() |
![]() |
#29 |
Parts and more parts
Join Date: Nov 2003
Location: Lebo, Kansas (middle of nowhere
Posts: 6,821
|
Re: engine popping at wot
Has anyone discussed the issue of the valves floating in this issue. You are getting backfire condition at WOT. It is very possible that a valve spring is weak and the valve is not seating when you are firing the cylinder. If you are running lean, the detonation would be more noticeable, but that can be evaluated with the color of the plugs and the respnse of the motor using acceleration characteristics as a troubleshooting technique.
Just out of curiosity, did you change out the fuel pump, also. I put an aftermarket pump (Edelbrock pump and solid fuel lines to my engine and I get some vapor binding in my engine and it casues the truck to cough and back fire until I flush the hotter fuel out of the system (on the open road). I purchased a bunch of needles and seats for my carb and adjusted the transition and WOT conditions until I was happy with that, but the cruising around city streets causes the overheating issues. |
![]() |
![]() |
![]() |
#30 | |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
Quote:
|
|
![]() |
![]() |
![]() |
#31 | |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
Quote:
No i didnt put a new fuel pump on the fuel filter is always full of gas so i dont think that would be the problem |
|
![]() |
![]() |
![]() |
#32 |
is Certifiable
Join Date: Feb 2008
Location: Hinesville, Georgia
Posts: 160
|
Re: engine popping at wot
Blue smoke on start up is most likely valve seals.
Here is a nice link for plug readings. http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html
__________________
1972 Chevy C10 LWB 350 Auto Blue with a white roof. |
![]() |
![]() |
![]() |
#33 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
what other color could it be just on start up?
|
![]() |
![]() |
![]() |
#34 |
Old Skool Club
![]() Join Date: Jun 2001
Location: Benton, AR "The Heart of Arkansas"
Posts: 10,880
|
Re: engine popping at wot
Old school stuff: Blue smoke on start-up is supposed to indicate worn valve stem seals. Grey smoke is fuel-related. White "smoke" is moisture, either from being cold (condensation in the air) or (if up to proper operating temps) white "smoke" indicates POSSIBLE condition in which coolant is entering the combustion chamber.
A little blue puff on start-up ain't gonna hurt anything. The wifes' Lexus does that and I'm not about to tear into that. It doesn't use even a 1/2 pint in 5K miles...... If you still have a points/condensor distributor, the points could be "popping". This is caused by a defective condensor, which will be indicated by a build-up on one side of the points. By this I mean, when you look at the points, you may see a pointed mound on one side of the points. If you do have the original distributor, you should seriously consider upgrading to an HEI. You could get one from a junk yard, but I would recommend a reman unit. You can pick one up for approx. $100-125. ACCEL has a nice one. When you check NAPA, AutoZone, O'Reilly's, you'll soon learn that they all sell the same remanufactured unit, with a little fluctuation in price. But, they all have the same unit.
__________________
Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was. |
![]() |
![]() |
![]() |
#35 |
Registered User
Join Date: Sep 2007
Location: Emporium,Pa
Posts: 248
|
Re: engine popping at wot
When I pulled my plugs weekend before last the color was normal, no moisture at all from either gas or oil. I just replaced the timing chain last year.
__________________
"When you were born, you cried and the world rejoiced. Live your life so that when you die, the world cries and you rejoice." [Cherokee saying] 2001 Dodge Ram Sport 1500 4x4. (old ride) 1987 GMC V1500 Sierra Classic ("new" ride) |
![]() |
![]() |
![]() |
#36 |
Senior Member
![]() Join Date: Oct 2005
Location: south carolina
Posts: 658
|
Re: engine popping at wot
I had a 305 with a worn lobe on the cam and it wouldn't do anything except sputter and it ran real rough. good luck, these old trucks can be alot of fun but they can also be a pain in the @ss.
__________________
1972 chevy cheyenne 10,nothing special at the moment,Its a work in progress, Working on the engine, paint and body,engine, paint and body,now its the suspenion, ahh hell I'm about tired of working on it. Maybe it will be a rat rod. ![]() |
![]() |
![]() |
![]() |
#37 | |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
Quote:
I have the HEI already |
|
![]() |
![]() |
![]() |
#38 |
Registered User
Join Date: Jan 2007
Location: Mississippi
Posts: 2,121
|
Re: engine popping at wot
Chunk the Edelbrock carb!
__________________
'72 C to K20 "Cannibalizer" http://67-72chevytrucks.com/vboard/s...32#post8653432 '85 K30 "Big Nassy" '01 2500 Suburban ...party wagon & tow truck '06 Silverado SS...DD '06 C1500 WT...DD '07 Classic C1500 WT...DD Built & sold cause can't keep 'em all: '72 Blazer "The Bucket" http://67-72chevytrucks.com/vboard/s...d.php?t=433190 '55 Chevy straight axle gasser https://www.trifive.com/forums/showthread.php?t=173938 '69 Pro Street Chevelle http://www.chevelles.com/forums/showthread.php?t=332541 '86 M1031 CUCV http://67-72chevytrucks.com/vboard/s...d.php?t=553619 |
![]() |
![]() |
![]() |
#39 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
|
![]() |
![]() |
![]() |
#40 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
yeah but no matter what i always love my truck!! well most of the time unless im stranded somewhere when it breaks down! which was just once lol
|
![]() |
![]() |
![]() |
#41 |
Parts and more parts
Join Date: Nov 2003
Location: Lebo, Kansas (middle of nowhere
Posts: 6,821
|
Re: engine popping at wot
I imagine that there could be something wrong with the carb, but I have run the AFB design carbs for awhile and they work real well, when you tune them. You might try bolting on another carb for a trial. See if you know someone that has one on their truck or car that you could try out. It still sounds to me that you are in a lop for your valves or ignition causing the back fire issues. Just what is your timing set at?
|
![]() |
![]() |
![]() |
#42 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
ok ill try my friends carb but it is the same exact model and everything lol but maybe his is just tuned right? he has the same year of truck his is just a gmc so it should work i hope if it does ill just accidently forget which one was mine and switch them!! haha
i think i had it set at like 8? ill check tomorrow at lunch for sure i have my test light in my toolbox lol |
![]() |
![]() |
![]() |
#43 |
Parts and more parts
Join Date: Nov 2003
Location: Lebo, Kansas (middle of nowhere
Posts: 6,821
|
Re: engine popping at wot
I suggested the carb swap to alleviate one possible failure point. If the truck still pops at WOT with the new carb, then your problem is outside of the carburetor and is something else on the engine. If it were mine, I would set my timing at 10 degrees BTDC and then adjust the idle for 700 to 900 RPMs in DRIVE. That way you are getting a little advance on the ignition. I am still working the idea of bad ignition or valve spring. When was the last time you put gas in the truck, is it bad?
|
![]() |
![]() |
![]() |
#44 |
72 chevys 4 life
Join Date: Aug 2008
Location: Crescent,Ok
Posts: 406
|
Re: engine popping at wot
yeah i havent got to try the swapping carb thing yet but ill set my timing at 10 BTDC then do all of that. NO the gas is good i drive this truck everyday =)
|
![]() |
![]() |
![]() |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|