No Power when Air temperature is hot

[johna_99_99]

i tried a search but couldnt find solution......my car is a 92 240sx DOHC. when the air temperature is cold(below 40F) my car pulls real hard but when it gets warmer outside(above 40F) the thing has no power at all. im real frustrated about this problem....any help would be great....thanks

[1991S13]

When air is hot, it isn't as dense as it is when it is cold. So when it is cold out, your engine is actually getting more air than when it is hot. Do you still have stock intake? I doubt the TB/intake manifold would have anything to do with it, maybe replacing the airbox with a cone filter or just getting a cold air intake would help out. If money is tight, you can take the resonator off the airbox and saw off the bottom of the box so it is less restrictive.

[johna_99_99]

thanks for the reply.....i put on an intake and thats all.....the problem is much worse than you think.....when its hot out my car is a piece of crap...has no power at all......when its cold outside its like driving a completely different car.....i realize the car will have more power when its cold but that much more??????

could it have something to do with the transmission? when the car has no power and after turning a corner then pressing on the gas the car feels like its in 3rd gear and i have to floor it just to get it going. but when its cold out the problem goes away....is it just coincidence?

[lancefloyd]

hmm...before you call it on the weather, consider the following:

Have you replaced your Rotor, Cap, Plugs, Wires, Fuel Filter, checked your EGR system, checked your AIV system, checked your PCV system, etc.? Also, check timing, as your car may be pinging and de-tuning itself in warmer weather. This may also have to do with fuel grade. Give all that a shot.

[johna_99_99]

thanks for the reply.....the cap and rotor are fine.....new plugs...plug wires are fine...new fuel pump.....new fuel filter......cannot be the gas.....this has been going on for 2 years now......i store my car for the winter.....runs like crap all summer....runs great when i just take it out or just before i put it away when it gets cold......i dont even want to drive it this summer.....an old piece of **** van could beat my car.....im very frustratted...

[:: orion ::]

Test the coolant temp sensor per the FSM, or just replace it...it can cause symptoms as you're describing.

- Brian

[johna_99_99]

thanks man.....do u know where i can get an fsm??? for free?

[1991S13]

There is a site you can download the FSM for free from, however I don't have the link.

I got it from a post on here, search around and maybe you can find it.