Alright boys, this one's a stumper, it's been getting worse as time passes and I haven't been able to localize the problem. Story time.
She's a 2.4 2000, about 85k miles. Standard maintenance. Mostly Freeway driving.
A while ago, I noticed that my car was idling higher than the usual 700-900 range upwards of 1200, I checked for vacuum leaks, checked against my Boost Gauge, checked and tried to visually inspect every hose/connection to the Supercharger, nada. I chalked this up to a crappy o2 sensor, Nothing serious, didn't throw any codes, didn't do anything out of the ordinary.
A few months go by, Spark plugs and oil changes later, standard maintenance. I'm noticing the idle gets a little rougher and the car begins to do some strange things. From time to time, once I get it into say, second gear, the car will studder and hesitate and gain absolutely no power. It's a pretty harsh hesitation too, it will pick up and lose power quickly at about the 2k+ RPM Range. If I turn the car off, it seems to go away for a while, then seems to come back intermittently mostly when the car warms up.
Today? While sitting at a stop sign, she just cut out, entirely. Started right up, but couldn't idle, she'd die again immediately. I managed to keep her going if I kept my foot on the gas, got her to the side of the road, stared at her for a bit, didn't smell anything burning, burned clean with no smoke of any kind. Threw a code sometime during this, I haven't gotten this checked but I wager it's a P0133. She didn't feel like she was misfiring as the CEL would flash if she was misfiring. After a few minutes of sitting, she started up and started working just fine again. Albeit with the usual higher than expected Idle.
I can't tell what I can attribute all of these problems to. If my O2 sensor is fouled I would expect something less drastic than this. It could possibly be spark gap, but given the intermittent nature of the problems, I would expect it to be something other than spark. Possibly a IAC or even a TPS Problem?
I'll update this tomorrow once I have a code to work with, couldn't get to it today, but Any insight into where I could start would be great. If she was doing something like smoking or misfiring I could localize the problem, but the nature of this problem has me stumped. Any insight would be great.
Sounds to me like you might have a loose, or broken vacuum line.
Rich Grayo Jr. wrote:fuel pressure test shows...?
Completely slipped my mind. I should check that and see if it's attributed to the fuel filter and pump. The pump does make its startup sound when the key is activated, but that's never a telltale sign of a properly functioning fuel system. Gonna go through some checks starting at the throttle body in a bit. I'll update this later.
Fixed by the way.
Turns out that at WOT, the head was sucking in an excess amount of air through a royally chewed up fuel injector O-ring. I was definitely surprised it had degraded so much. I replaced all of them, reseated the fuel injectors. Problem corrected itself. Took me forever to find it.... Consider this case closed. Idle is back down to stock 700-900 ish. No problems as far as I can tell, she runs just as well as she did when I bought her in 05. Thanks folks.
Now to buy a new battery.
