Down on power :-(

[Ciotti]

The car hit 180,000 miles and decided 300 horsepower was just too much work, it's bad enough that in third gear it doesn't have enough oomph to rev past 5,000 rpm so I know something is up. It doesn't feel like it's dropping a cylinder but it's hard to tell.

No codes or check engine light so I don't think it's IMRC related
Brand new rear o2's
Screaming Demon coil packs (3 years old)
FRPP wires (3 years old) (one got a bit cut and I electric taped it years ago and it's been fine)
Autolite plugs (brand new)
Fuel filter was replaced 3 years ago
Stock fuel injectors

As much as I don't want to, my first instinct is to buy OEM coil packs and a new set of FRPP wires but if that doesn't fix it I'll be pissed.

Any ideas?

 

[svtcobralover]

Id get a compression test done first just to make sure the motor is healthy.

 

[DVJ38]

Id get a compression test done first just to make sure the motor is healthy.

Exactly. Then if that's good, I'd check the secondary ports because they are probably real clogged if they've never been cleaned before.

 

[Ciotti]

Both awesome ideas, thanks guys


I also forgot to mention that gas mileage has taken a nose dive as well, I used to get 20+ pretty easily but lately I've been getting 15 or so.

 

[1996MysticSnake]

Check to make sure your cats are not clogged or the honeycomb inside them did not ball up. I had a similar problem like this due to bad cats but it was even worse i couldnt go above 25 mph

 

[Tabres]

Check to make sure your cats are not clogged or the honeycomb inside them did not ball up. I had a similar problem like this due to bad cats but it was even worse i couldnt go above 25 mph

I'm guessing he's not having that problem with his offroad h-pipe ;-)

 

[03cobra#694]

Fuel filter is 3 years old, hmmm... I'd change that sucker.

 

[mysteed]

Change the filter and run a compression test.

 

[my94pony]

Sounds like the problem I was having, switched my accel coil pack out for motor crafts and it's been perfect since

 

[97svtman]

i think its imrc mine were closed and i had no cel definitely wouldnt rev past 5k its worth it to check it not to rule it out and throw parts at it

 

[Wynn]

If I lived in Jersey I'd swing by and let you try my coil packs to eliminate that. And at 180,000 I'd clean the IMRCs regardless.

 

[Myzticsnake]

if you are gonna go through the hassle of cleaning them, id just delete them instead imo.

If it were the coilpacks id think it'd feel like it was missing up top, pretty easy to tell from my experience.

 

[SVT Pille]

Sounds like it might just need a simple tune up. Plugs wires coils and a fuel filter should be good to go as lont as the motor isn't shanzad.

 

[maniak87]

FRPP wires (3 years old) (one got a bit cut and I electric taped it years ago and it's been fine)

this could be your issue right there...

along with a compression/leak down test, id look into doing a fuel system flush

 

[FoxFour]

this could be your issue right there...

along with a compression/leak down test, id look into doing a fuel system flush

Ditto. Get new wires and I would suggest changing your front O2 sensors. They are probably very laggy and will cause your engine to run richer. Those aft ones were put there to check on the A/F after the cats, which you don't have anymore.
IMHO, I don't think there is a problem with your engine, it just needs some TLC. Oh, and did I say change your plug wires?:burnout:

 

[tomustang]

Check your fuel pressure too

 

[Ciotti]

Sorry I forgot to check this thread until now guys, big thanks for all the suggestions, here's an update...

Tonight the problem got worse, at 2,500 rpm it fell on it's face when I went wide open which rules out IMRC problems. I've noticed that it's not shaking at all when it goes down on power so I'm starting to think it's all cylinders that are losing power which rules out the cut spark plug wire and a coil pack dropping an entire bank of cylinders.

So, what I'm thinking is fuel pump which I don't have a problem replacing because 6 months ago the gas gauge stopped working and I know that the fuel pump is in the assembly that has the tank level sender so I can just replace the whole bloody thing and the fuel filter while I'm at it.

If that doesn't fix it I'll get a new set of FRPP wires (and kick myself for having to rebuy the dam things) and then I'll turn my blame to the Screaming Demon coil packs.


Front o2's are on the list of things to replace but I've been planning on waiting until the longtubes go on which might actually happen FINALLY this year(I've had them for 2+ years now)

 

[Cookieman00x]

You could just get a fuel pressure gauge from an autoparts store and see what the pressure is, that might save you some money. Also a tip for the tank, run the car to near empty, it makes dropping the tank that much easier without all of the extra weight.

Ill look around, I might have an oem set of coil packs you can try.

 

[Ciotti]

You could just get a fuel pressure gauge from an autoparts store and see what the pressure is, that might save you some money. Also a tip for the tank, run the car to near empty, it makes dropping the tank that much easier without all of the extra weight.

Ill look around, I might have an oem set of coil packs you can try.

Thanks brother I appreciate it, the car actually runs fine at idle and while cruising around, it isn't until I bring the revs up and hammer it that it dies. I'm assuming that's going to make it hard to check the fuel pressure or is there a slick way to get the gauge somewhere I can see it while driving?

 

[Myzticsnake]

if you have a hand held tuner you can datalog your car and see what might be happening. Check fuel trims, injector duty cycle, spark retard, etc, etc, etc.