Chevy 350 motor home engine problem

[pp_rp]

A friend has a 84 chevy 350 V8 motorhome with 50,000 miles on it. When this engine is cold upto 20 mins it runs great. After it warms up it hesitates bad from a stop and the engines seems to be missing when upto speed even at 70 mph. Sounds as if the engine is starving for gas. Why would it run good when cold and bad when warm? O' ya I forgot he runs 10w-30 Valvoline dino.

 

[Steve S]

Start with a complete tuneup and diagnosis .It is not the oil.

 

[pp_rp]

Quote:

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Start with a complete tuneup and diagnosis .It is not the oil.

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I know it's not the oil.. Just added that because this is BITOG...

 

[Chris142]

Those years have problems with the charcoal in the canister getting into the float bowl. Easy fix is an inline fuel filter on the hose between the carb and canister.............After you clean out the carb.

Runs better with the choke on points to a carb problem. Take it apart and see if you find little black rocks in it.

 

[mikeg5]

i agree with chris also i would tune it up good with ac delco parts

plugs
plug wires
distributr cap and button
pcv valve
seafoam treatment or chevron (the only two that i know that really works)
replace the other fuel filter also

 

[c502cid]

Too much guessing here and not enough diagnosing. Diagnose this, you already have some hints. Start with what you are given. Take off the air cleaner, and watch the choke. Is it pulling off when it warms up, my guess is not but then again, I'm just guessing like everyone else here. Diagnose, don't guess, these are easy motors to work with.

 

[punisher]

I remember a similar case on a Chevy truck. By 84 most of the cars had computer controlled systems, but the heavier series trucks/vans still had older style vac/manual engine controls. Those years can have a horrible vacuum line setup depending on emission certs. Some had more than one VSV (vac switch valve), vac delays. Some of the vac valves were thermostatically controlled, especially to distributor advance. If you have any vac leak, a broken plastic housing on any vac valve, or cracked vac delay, you get lean conditions. Some leaks are only apparent after the responsible VSV opens up and exposes the leak.

Long story short, make sure you have no vac leaks before you throw any money at this problem. As c502cid said "Diagnose, don't guess..............."