Series 2 L67 Laking Power *Data Vid Added*

[Mechanical Mike]

I believe 30,000 miles is about all you should expect from copper core spark plugs. A little knock could destroy them in less 1,000.

[l67poweredlss]

Do you think I should find someone to scan for knock first before I change the plugs?

[Mechanical Mike]

I'd do the plugs first. At this point they could cause knock.

[l67poweredlss]

Ok, I'll do plugs first. How much KR does it take to drop timing to -23? Also, does knock prompt the PCM to drop boost levels?

[Mechanical Mike]

I'm not sure of the answer to either of those questions. I've looked in the FSM for when the PCM will pull boost & all I could find is that it pulls boost while in reverse. I'm sure there's more to it than that. Keep track of which cylinder each plug comes from. It'll help if you find any bad ones.

[l67poweredlss]

Replaced the plugs today with no affect. Still -23* timing under WOT.

[Mechanical Mike]

Sorry for the delay in responding. I was hoping to get outside & try some experiments on my son's car but haven't been able to because he needed the car or the weather was crappy.
Let's get a couple more scans now that you have the new O2 sensor. At idle & 2000 rpms while in park & warmed up.
MAF
MAP
LTFT
STFT

If possible try to get that scan for knock. Where are you located? We may have a member near you that can help out with scanning for knock.

[l67poweredlss]

I'm in Lakeville, MN. My best bet is to contact either Nate or Marty. I'll get those scans to you by 2230 or so. I'll perform the test @ my work parking lot after the 30 mile drive.

[J Wikoff]

Two questions, and I might have missed them discussed earlier:

Have you verified your fuel pressure is what it should be?

Have you done a compression test?

[l67poweredlss]

Yes, tested fuel pressure @ 50PSI KOEO and 43PSI KOER. Have not tested compression. How would I go about doing this? Could I lose compression when the car uses no oil at all?

[J Wikoff]

If valves weren't sealing properly, yes.

You can rent compression testers from parts stores. You pull a plug, screw the tester in the hole, disable the injectors, and crank the engine.

[l67poweredlss]

How do I disable the injectors?

[harofreak00]

Disconnect the electrical connector

[J Wikoff]

Unplug the harness from them.

[l67poweredlss]

I see. What kind of readings should I get in the compression test?

[J Wikoff]

You want them to be consistant from one cylinder to the next, somewhere around 160 psi, IIRC.

[l67poweredlss]

Let's get a couple more scans now that you have the new O2 sensor. At idle & 2000 rpms while in park & warmed up.
http://www.youtube.com/watch?v=dr0jlUcO3Zk

It is a little different from last time.

[Mechanical Mike]

A lot different than last time! Video was quite blurry but it looks like STFT was in upper right & LTFT was in lower right. LTFT was maxed out (16.4) while idling. This indicates a good sized vacuum leak. Try spraying throttle body cleaner or CRC MAF Sensor cleaner around the engine to find the leak. Make sure to spray it on the EGR tube, all vacuum lines, bottom of the fuel injectors & around the super charger & throttle body gaskets. If no leak is found on those areas then try disconnecting & plugging the vacuum line that goes to the EVAP canister. Scan the fuel trims while the engine side of the line is plugged. Trims should be very close to 0.

[l67poweredlss]

Yeah, when I made sure all my vac lines were clean I probably screwed something up. lol

[l67poweredlss]

Its been solved! 1fatcat showed me the way the BCS is supposed to open and shut on a blower he had sitting on the table. Mine was too stiff and wasn't opening up all the way. Sprayed some WD40 and loosened it up. Fells like i've gained 100whp.
'.