Why does my carbed 4.3L start to backfire and crap out at idle when it rains? - Team Camaro Tech
Engine General Engine Discussion.

LinkBack Thread Tools Display Modes
post #1 of 2 (permalink) Old Apr 4th, 03, 10:35 PM Thread Starter
Gold Lifetime Member
Join Date: Aug 2001
Location: Forks, PA USA
Posts: 1,011

I just gave my truck a good tune-up to fix what I thought was an exposed coil or broken cap, but it turns out it still starts to "pop" out of the tail pipe and shake at idle when it rains. Off idle the engine runs really well for a carburated(4brrl) 1986 4.3L. (there is so much emissions crap on this thing)

It also ran really crappy when it was real cold out too (30-40F)

Oh yeah, here's another thing: There is always oil in my enclosed air cleaner area. The breather gets gunked up a few days after i put a new one it, the PCV valve is functional(when i take it out and shake it, it rattles). That's another reason, the emissons crap pisses me off, so many hoses going everywhere to all these sensors and probably only half of them work.
Any ideas? I guess I should make sure all the HEI ignition wires behind the distributor are sealed from the elements.... I just thought it might be carburator related. I had the carb "rebuild" be a speed shop in Langhorn PA, but I never realy did anything as far as carb tuning, because I actually DON'T know anything about carb tuning... thanks for listening

so far: new coil, cap, rotor, wires, fuel filter. next will be, valve seals, spark plugs, and some chevron engine deposit cleaner.

1968 Coupe, 327ci basketcase project
1986 Chevy Stepside, 305ci/300hp
JIM68 is offline  
Sponsored Links
post #2 of 2 (permalink) Old Apr 5th, 03, 04:17 PM
Join Date: Aug 1998
Location: Waldorf Md. USA
Posts: 3,288

It sounds like an ignition problem to me. The carb would not really be affected by wet weather. The fact that you are getting a lot of oil in the air cleaner is a clue to the fact that the engine is probably pretty worn out. Rings are about the only thing that will normally cause that.
All that being said...I know it is hard for any of us Hot Rodders to pay someone to work on a vehicle, but considering how much money you have spent already without fixing the problem, it would probably worth it to pay someone to put an ignition scope on the truck and try to find the problem. It could probably be duplicated with a fine spray from a hose while the scope is hooked up.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md
1971 Chevelle "Heavy Chevy" original owner

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BillK is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome