Loss of power after longer drives.

[DonM]

After a 30 min drive my Ex looses some power and acceleration is poor. It pretty much feels like a dog after so many min of driving. Feels like a 20-30hp loss!! Maybe more...

Im assuming this is because of the engine is very warm and is stealing power? Or an actual problem.

What do you guys think?

 

[jimbo74]

after being warm, it should actually run better, unless your air intake is being severly heated up somehow?

 

[DonM]

Not sure how that could be?

Doesnt warm air rob the engine of power? Cooler air is better, correct?

 

[jimbo74]

the engine is supposed to run more optimumly and cleaner when warm due to more complete combustion, etc......

that is correct about the air, denser and colder is better...

what i was saying, if after a long drive, somehow the intake stream maybe getting preheated? that would hurt power..?

 

[Alec]

try cleaning your MAS.

 

[DonM]

Oh ok.

Alec, MAS is less then a year old.

 

[Alec]

Doesn't mean it's clean.

 

[DonM]

All righty then, I guess I will clean it later today.

Anything else I could also look into?

 

[TPLYNCH]

Are your Cats still original???

 

[DonM]

Yes, but I had them checked out not to long ago.

Some one told me about a little trick to testing the cats on this board. While going 50ish mph, stomp on the gas. If it hesitates then theres a good chance the cats might be gloged.

When I did this, i felt no hesitation. I realize this might not be a very good way to test the cats, but I did have the shop check them not to long ago.

 

[DonM]

Alec

MAS is clean. Reset the computer and no change after about 20 miles of driving.

Ive looked at all the vaccum hoses a couple times, all is good in that departement. First 15 min of driving, the power is there. Then it just feels slow and underpowered.

What else could be the problem?

Thanks

 

[DarkFox1]

do you suppose it might be something to do with the thermostat? maybe not doing something it should? I'm thinking it might have something to do with temperatures

hows yer temp guage?

btw I'm not so sure about that cat check, my truck hesitates a full second when I give it any throttle changes at all and my cats, according to a back pressure test... are as good as new, I dont really see how clogged cats would cause a delayed effect like that anyway, unless they're heating up or something

 

[DonM]

Darkfox, im not sure about the Thermostat. My temp guage never goes much past the first line. So the engine never overheats. It's been only doing this since January, maybe longer.

It's just a power loss while the engine is really warm. I could shut her down and let the engine sit for more then an hour and will be fine again. Only for a couple min.

Not sure if I mentioned this above, but the acceleration is bad also. But good for the first 15 min or so of driving. Then disapears with the power.

 

[Alf]

maybe the problem are the spark plugs or the wires prove them and clean the air filter it coul help. if you have problems whit the thermostate and the weather in your town is warm you can quit it.

chek if the radiator is dirty.

 

[DarkFox1]

you know our old pontiac does that, infact if you shut it off hot it wont even start.. you may wanna get those cats checked by another guy or sumden

 

[twizard27]

I see you have the Apten chip. Maybe that could be the problem? Have you tried driving with out it? Other than that it may be related to a temp sensor somewhere.

 

[DonM]

Originally posted by Alf
maybe the problem are the spark plugs or the wires prove them and clean the air filter it coul help. if you have problems whit the thermostate and the weather in your town is warm you can quit it.

chek if the radiator is dirty.

Ive never had the radiator flushed since Ive owned the Ex. It's about to turn 100,000 miles by the end of the week. Maybe it would be a good idea anyway.

I changed the plugs and wires back in April, problem started well before this.

Darkfox:Im not so sure about the cats being the problem though. Maybe someone could help me understand how bad cats could cause my engine to loose power after 30 min of driving.

:twizard27: Problem started before the chip

 

[DarkFox1]

tryin to do mods to see if it goes away? yea I did that with mine.. thats why I have a kkm and a flowmaster.. you didn't see any change with the chip?

the fluid flush maybe a good idea, my raditor hoses went out at about 70k so mine has been flushed since, if you have rust or something in there.. I mean, I'm not an expert so I can't tell ya how that would work.

cat wise.. my only guess is as they heat up they might start to add resistance to your exhaust system.. again, no expert so I can't say much more than that lol

 

[DonM]

Yeah, the chip seemed to help other problems out, but not this one.

Next week i'll flush the radiator and maybe check the Thermostat. Then have the cats checked again.

More rain coming. No sun till next week. Cant get anything done.

 

[Slick Rick]

If I were you I would check out the

Coolant temp sensor. Think about it. You haven't flushed the system since owning the car. The coolant sensor is probably a little bit dirty, ( due to the lack of coolant flushes ) and is giving the ECU the wrong info when it gets to a certain temperature.


Good Luck.