Author Topic: Reduced performance in extreme heat?  (Read 1617 times)

Offline Benji808

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Reduced performance in extreme heat?
« on: June 21, 2022, 04:14:33 PM »
St Louis summer. Today it's ~110 standing on the pavement, with high humidity and limited wind.

I have a '75 Eldorado with a rebuilt quadrajet using Cliff's kit. It has been working great for several weeks.

Today the car seems to be a bit sluggish in acceleration (will even lose a bit of speed going up a hill at 70mph, even at WOT), and occasionally has a minor sputter going WOT to accelerate. Also seems more difficult to hot start (it will "start" almost right away per usual, but then may die and need a few pumps). Doesn't affect overall driving much, but definitely feels different. Is that normal/expected given the heat? Maybe a little fuel vaporizing or something? Or should I be looking elsewhere for a cause?

To be clear, I do not believe the car itself is overheating - it's measuring a bit hotter than usual (~195 at the thermostat vs usual ~185), but nothing crazy. I just replaced the accessory belts and had some suspension work done, but other than that the heat is the only real change in the past few days.

40+ year old car, so obviously not ruling out other things going wrong, but for further context engine has been rebuilt recently, distributer/sparks/wires, etc, plus fuel pump all new in past year or so.


Offline Benji808

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Re: Reduced performance in extreme heat?
« Reply #1 on: June 21, 2022, 06:33:37 PM »
Nevermind - found an unplugged vacuum line right off the carb going to the thermo vacuum switch, so that's probably it. Sometimes it's the little things LOL.

Offline Cliff Ruggles

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Re: Reduced performance in extreme heat?
« Reply #2 on: July 13, 2022, 04:07:17 AM »
Good news that it was something pretty simple...