95 k3500 is a dog pulling trailer in hot weather,,,

[94GMC2500]

I have a 95 k3500 dually with new Diamond Eye 4" exhaust, walking J chip in computer. manual boost control, snorkel removed from air cleaner, inlet in air cleaner box opened up, high flow water pump, dual stats, late 6.5 fan, HD fan clutch. I pull a 28 ft Pace American trailer. It pulls ok in cool weather, in hotter weather with the AC going the truck is a dog.



Is it normal for these to drop off so much in power in warmer weather? Is there much I can do to help it?



Tom W

[DmaxMaverick]

There will be some power loss going from cold climate to hot, all else the same. Usually, moving away from winter fuel offsets the loss. Hotter air not only heats up the engine coolant and compartment, it's less dense (less O2). The turbo can compensate, mostly, for the density, but the higher temps can cause the PCM to defuel. Your chip may not be compensating for this, or it's actually hitting a temperature wall. It's hard to say. Warmer temps also means warmer/thinner fuel, which can become more evident with a worn injection pump. When performance decreases summer to summer, look for something that changed. A dirty/fouled cooling stack is a good place to start.

Optimizing the system, including injection timing (TDCO), can do a lot to maximize performance

[trbankii]

snorkel removed from air cleaner, inlet in air cleaner box opened up

Pulling in all the hot air from underhood is only going to make your issues worse.

[94GMC2500]

It is still pulling air from the hole in the fender. Also when I said better in cooler weather I meant like 65 to 70 degrees, it falls way off in 80 to 85 degree weather. I ordered one of those electric fans that goes behind the grille that I read the towing package had. Maybe that might help a little.

[trbankii]

Ok, I've seen people open up the airbox to underhood or put a K&N-style filter on the input side of the turbo and thought you had done something like that.

80 to 85 degree weather really shouldn't be enough to significantly affect performance. Have you cleaned out the front of your radiator recently? I know I've been amazed at times at how much collects down there - blocking airflow. DMax mentioned this - "A dirty/fouled cooling stack is a good place to start."

Are you seeing higher coolant and oil temps when you're having issues? That would tend to point to a cooling issue.

[94GMC2500]

Its clean, I just had the condenser out to flush it and replace the orifice tube to fix the ac. it seems like when I use the ac the water temp and trans temp go up.

If I turn on the ac at idle the I can hear the engine working to turn the compressor. High side pressure is about 210 in high 80s outside temp.

I have been thinking of getting one of those air to air intercoolers and mount it under the bumper at a angle to some what protect it.