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post #1 of (permalink) Old 04-19-2002, 07:21 PM
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Surging problem with my new 355!?!? HELP!

Ok my engine periodically jumps from like 600RPM to 850RPM at idle. I set the timing at 8 degrees BTDC and adjusted the idle screw to 850 RPM, but then this started happening. It wouldn't be my exhaust leak from my header would it? I'm going to get that fixed soon.

As for the surging problem I've been driving it up and down the backroads to kinda put some miles on the motor, and I can feel surging in 2nd and 3rd gear (SM465). Any idea what is causing this? It's about to drive me nuts! All I need to do is get the motor squared away and then the brakes and then its time to lift and put tires on![img]images/icons/laugh.gif[/img]

Also about the timing when the truck is cold it takes it forever to crank turns and turns and turns and turns, but once it's warm it'll start on the first lick!(confused!) Do I need to adjust my timing back more? Maybe 6 degrees BTDC?

A buddy of mine seems to also think that the surging problem is valves to tight? Which I don't think it is because I adjusted the valves while the truck was running.

Sorry for the short novel but I have these several things I need the boards help with so if you can give me any advice I would gladly accept it!
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post #2 of (permalink) Old 04-19-2002, 08:39 PM
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Re: Surging problem with my new 355!?!? HELP!

Sounds like your carb needs some tweaking. The cold start issue sounds choke related and the surging (at least at idle) can be fixed with idle air adjustment
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post #3 of (permalink) Old 04-19-2002, 08:49 PM
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Re: Surging problem with my new 355!?!? HELP!

Not sure of the procedure you used to adjust the valves but you may want to double check the adjustment. I have found that on a new cam/lifter set-up the lifters are generally good enough to rely on enough springback to set initial valve back lash. With the engine running and not enough oil pressure to load the lifters, you can cause floating of the valves (or worse) by adjusting them by ear/feel.
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post #4 of (permalink) Old 04-20-2002, 11:22 AM
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Re: Surging problem with my new 355!?!? HELP!

Well to adjust the valves I would start the truck, let it get to operating temperature, then shut it off for long enough to take the valve cover off. Then I would start the truck back up and back off the rocker arms until I heard them clicking and then I tightened them back up until the quit clicking and then I turned it another 1/4 turn.

I don't know what this is but I'm about to go talk to a mechanic friend and then basically take it to him and have him help me figure out what it is.[img]images/icons/frown.gif[/img]
post #5 of (permalink) Old 04-20-2002, 12:33 PM
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Re: Surging problem with my new 355!?!? HELP!

Just a couple stupid ideas, but

is your solenoid for air conditioning bumping up the idle?

what about the EGR valve?
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