Hi Guys,
Im new to the forum but I think im a candidate for the hesitation club already.
My car is a legacy wagon with a 96 Jap spec wrx engine and am having similar hesitation problems as some of you have described. Mine seems to happen when the car has warmed up well. When you put your foot flat to the floor around 3000 rpm it will pick up ok and then when you reach 4000rmp it starts to bog down like someone is pulling the handbrake on lightly and then when you make it to 5000rpm it usually clears up again and pulls hard. I though I heard some pinging the other day it did it to.
It doesn't do it all the time which makes it more frustrating to solve.
I had a similar problem where the car used to cut out suddenly and backfire when reaching peak boost around 5000 rpm. I initially thought this was some sort of boosting problem but ended up being a bad coilpack.
I havent solved the other problem though has anyone else?
lenm555, I have the same problem only it happens at 5000rpm. The engine will be strong until that point, and then will be sluggish (still smooth, though), and then pick up again after 5500rpm. I'm thinking the ecu is pulling timing at this point.
a/f ratios are still fine during this period. I'm eventually gonna get either a J&S safeguard or S-ITC sometime to see if that helps.
lenm555 : so you have the same exact problem as me, except that mine's doesn't come back at 5000rpm... i'll do some checkup's again when the weather will go up .. (at -25 (-37-40 with the wind) it's not good time to do some mecanic outside... :\ )
One of the guys on the www.nasioc.com forums owns a wrx that is experiencing the same problems. He's assuming it might be the winterized gas. I've just starting noticing this problem when the weather got really cold, which makes me suspect the same thing. The guy on the board is datalogging his car's sensor measurements, and hasn't noticed anything too out of the ordinary. I'll let you know what he tells me.
