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No boost problem and car running weird

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totaleclipse_05

15+ Year Contributor
1,037
36
Apr 22, 2005
Hutchinson, Minnesota
Hey guys, I posted this over on 2GNT already, but decided to try here also in case someone has an idea.

Not sure if this involves what my problem may be, but I thought I would add it. I was boosting a little bit last night and I noticed it was building pretty slow. I was trying out a different boost controller that I got for cheap to see if it works and thought it was probably it that was doing it. Now on with the problem.

A little laster I was at a friend's house and got stuck in the snow in his driveway (kinda in the ditch on the side). Front passenger side front got kinda stuck. As I was trying to rock it out, the car started to idle really weird. Vacuum went down to about -5 and idle was terrible. Air/fuel gauge was in the green and eventually died. Kept starting it back up after a little bit and would idle rough and die again. Finally it started, idled rough, then returned to the right idle (my car idles at around -15 to -17 vacuum). Got it out and took it on the road and I floor it and the boost gauge goes to like -3 vacuum and no boost. I am on open downpipe right now and I hear the turbo spooling noise still, but I couldn't tell if a pipe had blown off because of being stuck. This morning I pull it in the garage, take off the bumper, and check over everything. All couplers and piping are still attached tightly. I took it for another test drive and same thing as night before. Flooring it only gets to -2 to -3 vacuum on the gauge and no boost, but the car starts and idles fine now. Checked over all vacuum lines and they are still good and connected.

Took the boost controller off completely and ran a line from turbo to wastegate and still the same. I think it may be a sensor problem somewhere. I had a similiar problem like this when I had my power wires mixed up for my FCD (I think the 5v for the MAP sensor and the 12v power for the FCD) I had switched those back and had boost. I tried a different MAP sensor from my eclipse though in case the one had gone bad and still the same. Could the O2 sensor maybe be the culprit? Maybe got wet from the snow or something? I took it for a test drive not to long ago and whenever I would lay off the gas, the Air/Fuel Gauge I have would go all the way into the red and off the gauge so none of the LED's would light up. Also when I try flooring it, the Air/Fuel only gets to the First green LEDs instead of all the way on the far right like it used to. Anybody have an idea what it may be?
 
Not building boost could be from having an exhaust leak or your wastegate's spring not sealing correctly. You might've broken something lose along those lines. As for fuel, I don't know what to tell you, but the wiring on the 1st o2 sensor should be fine as it sit about half way up in the engine bay. Good luck.
 
OK I figured it out guys. I had another CEL that I didn't know of, it was the MAP sensor voltage too high or low. I brought the FCD voltage down to 4.51v instead of the 4.61v I had before and it runs great now. I guess the year differences between my 99 Eclipse and this one didn't like the same voltages. Thanks for the help (and space ha).
 
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