My truck runs like a raped ape when it's cool, but on a hot day, after the engine gets up to higher temps (around 12 o'clock on the temp guage - I'm guessing it's around 190-200?) it loses power significantly. Throttle response gets pretty bad, and low RPM torque goes into the toilet. Other than the power loss, it runs fine, with no check engine lights, engine misses, or other symptoms. Anyone have a thought on where I can even begin troubleshooting this? Thanks for your ideas.

 

have you tried to run for codes? even if the cel isn't coming on there could still be some errors... www.fordfuelinjection.com will show you how. Also, how was the gas mileage affected by this?

 

I haven't checked it for codes yet. I can't get it to my friend's shop until next Thursday (he has the scan tool), so I guess I'll try the paperclip trick tomorrow. I haven't noticed any mileage changes, but it's possible. I'll fill it tomorrow and check it.

 

Does your k&n suck from under the hood or the fenderwell? It could be the underhood temperatures are rising and your intake is sucking in hot air. This would cause a little power reduction, but not as much as you make it sound.

 

That's a good thought. It is located at the location of the original filter box, which is underhood, just forward of and above the fender. I'd like to hope that the e-fans are pulling enough fresh air into the compartment to provide sufficiently cool air to the intake, but anything's possible. Still, the power loss is blatant, almost like it's intentional, like the ECM is doing it on purpose, in response to some condition. I was too busy fishing yesterday to check for codes (I have my priorities straight), so I plan to have a go at it today.

 

as suggested, pull the codes.

Then come back with results.

 

OK. I am stupid. I thought for some reason that I could do the self test, as shown on www.fordfuelinjection.com, but OBDII (96 and newer) has to be done with a code scanner(right?)... It'll have to wait until I can get access to one. What a pisser.

 

Ah yes, I missed the part that you have a '96 as well.

Correct, yours is OBD-II and need to use a scanner.

Hit up your local parts house, many of them pull codes for free.

 

Really? Sweet. I'll do that. My mechanic friend is 45 minutes away, so it's a hassle to get to him. Thanks Humboldt.