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Sputtering 350 :(

1K views 4 replies 4 participants last post by  Aerotech  
#1 ·
So about 2 weeks ago I was driving through town and went over a bump and my truck kinda stalled a little bit.....ever since then my throttle response sucks and has been running sluggish I own a 1986 chevy 3/4 ton 4x4 any ideas on what it could be? I thought that maybe since I was a lil low on fuel i might have sucked some crap up from the tank so I changed the internal fuel filter in my carburetor but still does it Imma go check spark plugs to see if maybe somehow they may be fouled if there ok Imma check the timing other that that I dont know what it could be wouldnt think the carb needs adjusting since the plugs are still there never been removed.
 
#2 ·
Did you check the float bowl for trash? If there`s trash in the carb it`ll keep on running like crap until it`s flushed out. Trash can get in the small passages to the boosters and idle circuits and when this happens it`s not gonna run right. Check the carb out closer then do all the checks you mentioned. Also check it for vacuum leaks. What shape is the tune up in? If it`s past due I`d add that to the list.
 
#3 ·
well i checked the carb its clear i did a full tune up 3 months ago these damed pre gaped spark plugs piss me off lol they were pre gaped to .045 and they are supposed to be .035 its running better it will hold me over until the rebuild in two months ill keep u posted have pistons and rings on order right now and getting ready to order the roller rocker kit any suggestions on what I should buy.. also wanna buy intake and carb so any info on what would be best for lots of low end torque would be nice :D
 
#4 ·
Jerred said:
went over a bump and my truck kinda stalled a little bit....

Since you said there was a tendency of the motor to want to stall out and hasn't operated well since, I'm going way out on a limb here to suggest that it is an electrical ground problem, not a carb problem.

Clean all the paint and grime off a place on the firewall where you can drill a hole and get to it from the inside of the vehicle. Clean a place on the engine block and on the frame of the vehicle just the same way, down to shiny, clean metal. Count up what length of cable it will take to span from the firewall to the block to the frame. What I usually do is to make 2 cables. One end of cable #1 goes to the firewall, where you run a bolt and nut through the cable end and tighten it down from inside the vehicle. The other end of cable #1 goes to the frame. One end of cable #2 also secures to the frame at the same connection. The other end of cable #2 goes to the engine block. Now, you have tied the body to the frame to the motor. Use RTV to cover the connections front and rear to prevent moisture from oxidizing the connections.

What I usually use for the cables is #4 welding cable from the welding supply store. They have copper ends also to crimp onto the cable. In addition to crimping, solder the ends on and install heat shrink sleeves.

Even if this does not solve your immediate problem, it needs to be done anyway on any old car or truck that you're going to try to resurrect. Nothing works properly without good grounds.
 
#5 ·
Is it hard to start? Bad ground would do that, but dirty idle circuit might not, since you're giving it gas and mostly bypassing the idle circuit. Do some basic troubleshooting before tearing carb down or drilling holes. I had the same thing happen on my roadster, pulled up to a light and it suddenly ran like a dog. Turned out to be gasket fiber in idle circuit. Easy fix.