My engine just started to do this. Previously last month I had the fuel pump go out on me on the 91 freeway (sucked). Now when I press the gas hard to accelerate fast the engine just bogs out like it is either flooding the engine with to much gas not enough air or something else. It runs fine at slow acceleration and constant speeds .Car has 100,000 my injen air intake filter was replaced going to replace spark plugs what else could be wrong.

 

Are you not throwing any obd II codes?
If not then they should come soon and that will help narrow it down.

 

No lights have gone on yet. So I don't think the system will register it. It is progressively get worse. I'm hoping to replace spark plugs tonight and look at them to see if any one of them is bad causing it to misfire

 

clogged cat?
Easiest way to find out... drill a hole in the downpipe about 2 inch from the flange nearest the cat and go for a spin. If the problem goes away or isn't as bad, the cat converter is clogged and needs to be replaced.

Otherwise, plug-up the drilled hole, and keep looking.

 

I hope not I have a magnaflow high flow cat but would explain the difficulty on the acceleration having problems. Could be to much back pressure then and engine is having a hard time pushing exhaust out? but my gas mileage is not getting affected by this event at all.

 

Maybe a loose upper and lower intercooler pipes..

 

That is my initial guess. If you live in a area where you don't have to deal with salt on the road, the bolts that hold your cat to the rest of the exhaust line might be in good enough condition to remove the nut instead of drilling a hole in the exhaust. If that's the case, then it's even easier to try it out.

Either way... post your findings cause I have a similar issue going on and it's too cold/wet/snowy to start crawling under my car.

The OP's car is NA

 

I live in CA where it is actually raining but have a garage. My other guess is something is up with my fuel pump. I recently had it replaced by a mechanic who has been recommended to me as being good. I'm thinking he replaced the fuel pump with a pump that cant handle the flow. Being experienced with pump design I feel like when accelerating heavily it demands more fuel from the pump can handle and this causes cavitation in the fuel injectors causing the misfiring of the cylinders but this would cause a light to go off because i have experienced misfiring from another car. I dont know if fuel pumps are variable flow based of accelerator demand. Any thoughts about this ?

 

Sounds likely to me, if you've had this problem since he replaced to pump?

Could be a clogged fuel filter, only able to push so much gas through and when you need more you notice it.

No matter what it is, it should for sure trip a code.
May take 200 miles to do it but I think it's for sure gonna trip one.

 

well it should trip it but I drive 90 miles per day for work! Should have tripped it and it hasnt always been like this since he replaced it. Just started but he only cleaned the fuel filter not replaced it so it might be time to over haul the fuel filtering system since whatever killed my fuel pump might be working its way to my engine

 

Just read the EGR thread and I'm now wondering if a bad/clogged/sticky egr could cause an issue like this?

 

Well the problem ended up being prolly a very bad batch of gas that killed my pump first and clogged my fuel filter. Once the mechanic cleaned that all up it allowed the rest of the crap to flow into my fuel injectors. Then those shot into my engine and killed my spark plugs. The tips where seriously worn all the way down to the white insulator and they were all black because they were burning up all the sediment from the gas. Does any one know how to clean the gas tank out? will adding the fuel cleaner work well enough because I keep having problems with low idles every once in a while because i think some sedimentation keeps flowing in. Any ideas or recommendations