Sometimes my car has it, most of the time not. Usually has it when its cold and first started, but its also there randomly when its warm. Sometimes its a downright dog under 2500 rpms. It also vibrates/stutters a little. Also gets some pretty bad mileage around town. I can spend 8 minutes driving in the city and use the same amount of gas vs driving on the highway for 25 minutes. It gets about 35 mpg on the highway. 2.8 12v.

It has new plugs and a bottle of FI cleaner has ran through it. Also did a little decarbonization with half a bottle of trans fluid and bottle of water as per some instructions. No engine codes.

What do you guys think? Maybe throttle body is gummed up? First thought would be compression, but the torque comes and goes.

 

please explain what exactly you mean/did?

 

yea dude sounds like that right there could be your problem...why didnt you just use SEAFOAM?

 

Could be clogged cats.

 

Suck half a quart of auto trans fluid through a vacuum line, then suck the same amount of water in. Running the engine at at least 2500 rpms, the detergents in the trans fluid loosen and clean the carbon from the valves, intake, and pistons. The water flushes out the rest and any left over trans fluid. The motor ran smoother afterwards and seemed to have a bit more power.

The car has run a little rough at low throttle since I've had it. It runs great and scoots at 3/4 to full throttle, so I think clogged cats are out.

 

your serious? you actually did that? never ever ever ever ever put transmission fluid and water in your intake. ever. i cant even imagine how that would seem like a good idea.

 

ATF breaks down carbon deposits. I've used it on partial engine tear-downs to loosen up deposits stuck in ports or secondary air injection ports. It's not nearly as effective as carb cleaner or Seafoam, but it is a perfectly acceptable product to use and has been used as long as ATF has been around. I'd recommend carb cleaner if the engine is apart, Seafoam or BG products if the engine is running as they are the most effective products.

Water is actually a great way to steam clean the intake. As long as the amount is regulated to prevent hydro-lock, it is again a perfectly acceptable method of cleaning the intake. It's also method I've used before on my 1991 SHO, but results are not nearly as good as Seafoam or BG products. It's a better idea to use a chemical cleaner first and then use water to steam clean after. Water is pretty much useless to clean carbon deposits during an engine or top-end rebuild.

 

ive used ATF on parts when they are off of the car. but sucked thru the intake? i couldnt imagine a heavy-ish weight oil like ATF could be good for the cat or O2 sensors or spark plugs. the engine would have to be pretty hot to vaporize it on contact and not turn into sludge after mixing with the carbon. seafoam is good because it has a low viscosity almost like gasoline. i will never pour a can of ATF down my intake.

 

Anything that blows carbon into the exhaust is not really good for the cat.

 

Well, I'm going to inspect the throttle body and see how nasty it is. I doubt any of the methods above would clean the throttle body good enough.

I did wonder about the cats and O2 sensors with the ATF. The seafoam would have been a better idea. The ATF would probably be a better idea on older carburated cars.

Ignorance isn't genius fella. Never put water in your intake ever huh? I guess water/meth injection is a terrible idea. Nobody is dumping a gallon of water down the throttle body.