85 Caprice not Starting, but Only When Warm.

Aug 20, 2005 2 Replies

Hi,



My 85 Chevy Caprice, with carb, doesn't want to start, sometimes, when the engine is warm (as in being shut down for an hour after being fully warmed up). It runs fine when it's running. It starts when cold, and starts when hot. You can let it sit for a while, like 5 minutes (or more?), when hot, and it'll still start right up again. But somewhere around a half hour to an hour of cooling down will sometimes get it into the no start condition : cranking, smell of gas, but not even one cylinder firing. I am currently trying to check for spark, but I need to wait for a helper, since I can't crank the engine and hold the plug against the valve cover at the same time. :)


I can't find a coil wire on the dist cap, just the 8 plug wires and some small wires coming into the cap.



During one of the no starts, I tapped a bunch of electrical connectors in front of the carb, and it then started ! But when I do the same tapping trick now, it doesn't help.



If I let the engine cool all the way down ( 5 or 6 hrs) it starts right up.



It doesn't ever stall out once it's runnin (knock on wood). I think it's electrical, but don't know what to check. Is there an ESC module on this car?



Temp sensor going bad ?



I can see gas squirting into the carb when I move the throttle, and see the gas mist oozing up out of the carb, so there is gas. The carb is the orig, and it's idling too high, can't adjust it down with the idle screw. Maybe the carb is leaking gas into the engine, when it's off, and flooding it ?



Thanks for any help ...



Sounds like you've got 2 correct ideas. First, determine whether you have fire. A plug wire-test will do just fine. (The coil is inside the top of the dist. cap; hence you found no coil wire, as on older ones.) If good, then remove an easy-to-reach plug after it has sat long enough to not start. If it is wet with gas, it may be time for a carb overhaul--quadrajets are known for leaking down, & flooding an engine, just as you surmised. HTH & good luck, s

Thanks. I have a no-spark condition, just found out, and am going to start anew thread about that. BTW, the plug was not wet

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