papaindigo wrote:
I honestly don't know if that's the right bypass method but it's not the one from the old post (finally found it but the picture is gone - EDIT but I was able to repost it below from my notes on the original post) and GDE comments on that post implies the old post has the correct bypass and I've checked my old vacuum assembly (goes with my old "surplus" turbo) and the picture matches GDE's instructions, included below. I think what you have done is hook the INPUT (not the OUTPUT) from the black plastic vacuum reservoir to the "VAC" port on the turbo EVM but whether or not that will do the same thing as hooking the reservoir OUTPUTto the "VAC" port I have no clue. UPDATE - not happy with PhotoBucket so went to ImageShack and can actually get pictures to appear on the forum
My notes say Failure of the vacuum reservoir solenoid (a.k.a. solenoid secondary runner valve per the parts fiche PN(PN 4606226AC) ) can produce several MIL/CEL codes and result is turbo boost problems. A temporary solution and diagnosis is to bypass that solenoid by rerouting vacuum lines as in the picture below:
by disconnecting the little hose from where the red arrow is and replugged it where the yellow arrow is (VAC port). If that solves the problem then leave the hoses in the new/temporary configuration and order a replacement solenoid. In the interim the vehicle may be driven; the CEL will remain until you replace the on/off solenoid. The only benefit that part provides is overnight storage of vacuum in the plastic reservoir so the turbo has vacuum immediately during the start. Without it you have a 2-10 second wait before the engine vacuum pump evacs the lines enough for the turbo vanes to move. Once the replacement solenoid is installed put the hose(s) back the way they were originally.
GDE's writeup for this says "By-passing of the on/off solenoid is very straight forward. Trace the vacuum line output from the black plastic reservoir to the input of the on/off solenoid. Remove this vacuum line and plug it directly into the turbo EVM on the port labeled "VAC". The turbo EVM is the one with the blue rubber isolator and vacuum line running directly to turbo."
Also you should probably trace back along the vacuum input line to the reservoir for a melted vacuum line as in topan's post at
viewtopic.php?f=5&t=61240As to the numbered items in your picture I think they are as follows
1 = EVM (electric vacuum modulator)
2 = vacuum reservoir solenoid
3 = vacuum reservoir
Absent a picture I still think your CAC hoses are shot and leaking air hence killing boost.
Ok, now I'm confused and curious... about the Jeep.
Quick history:
2005 with GDE FT tune and trans tune for last 60-70k miles.
145k-ish miles total.
The other day, I noticed that I had a little less power and a tiny bit of smoke from the back. I almost NEVER get black smoke on heavy acceleration, and this has been true since the GDE tunes. By less power, I mean that if I hit the accelerator hard to pass, I wouldn't downshift, and I would slowly pick up speed. I had NO CEL lights or codes.
My first fix was to replace the fuel filter. When I took the old one off it felt a little loose. I was pretty sure that was my problem and sure enough, my next drive to work seemed pretty good.
That night though, I threw a PO299 code. I was back to a little less power and a little black smoke. Nothing too scary, and everything sounded good while running. After reading all of these posts, I've ordered the solenoid, and I've completed the bypass based on these pictures. It seems great, and the CEL went off.
What has actually happened here? What made the PO299 code go in the first place, why does the bypass work, why do I now have NO CEL, and why do I need to replace the solenoid now that it's working?
If anyone is interested in helping me to understand this I would be grateful.
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