Hi there
Trying to clean a mess up on a 2007 Caddy XLR
The present owner bought this about 1 year ago and really regrets he did
To make it worse he knows nothing about how cars function or how to turn a screwdriver
The owner before that had the car sent to Chuck Mallet in Ohio who converted the 4.4L engine to 4.6 liter
Then added duel turbo in ass end, larger fuel injectors and who knows what else
New owner does not have any history of really what all was done but for some reason last owner
claimed the turbos were too large and had smaller ones put in place and for some reason the Caddy is
now on it's third PCM
Car ran like crap from startup to WOT,
He came to me to see if I can solve the problems that 3 other shops tried to do but failed
I use Tunercat and below is a print screen of the existing PCM calibration
There is one major issue that must be fixed and that on random basis when getting to 2-4K RPMs owner
says engine sputters and is horrid but soon as off boost engine runs very well
Being the tune in it was done by who knows who I did not have a stock flash in Tunercat cal format
What has been pinned down is random the AFR goes down to 10.x
What is unknown without a stock flash to compare :
For that year did this engine support variable timing and how many CAMs is engine supposed to have ?
did the PCM also command a variable fuel pump system ?
Present owner does not know either of above, nor if Mallet put a none variable CAM in and what was done to fuel system
Owner called Mallet multi times but only gets voice mail and never a return call
So I am looking to see if anyone has a stock GM calibration ? so I can do a compare
or better if having a Mallet tune for this year/model conversion with dual turbo so I can see if I can correct
though I think there is other problems also such as oil and water seen in MAF which is coming from a very large
inner cooler, some air leaks found and suspect waste gates fouled up
So if you have either a stock or Mallet calibration if you can share that here so I can clean the tune up
Thanks
Owner says today after car being at another shop
Shop found the fuel pressure stayed "rock solid" and tested the "fuel pump control module" and there was no issue w/ fuel delivery at that level.
Though the check engine codes I told you came on were both "lean", he found it was running rich (and in fact that's apparent via the "air/fuel ratio" gauge added to the dash.
It's always been 14+/- and now with acceleration it drops to 10).
He also found the variable cam timing that could be expected was actually always at zero (not variating).
He found some things w/ the turbo: there was no boost pressure at intake manifold while road testing.
He tested the boost system for leaks:
the blow off valve (Tial brand) is missing an O ring to the intercooler and opens with the engine idling (unfiltered air entering)!
There were small leaks in the right lower corner of the intercooler.
The purge valve is being commanded on during acceleration: "consider programming this event out".
He found just one waste gait in the twin turbo system operating w/ the right side only!?
One line from the manifold to that waste gait was clogged. He capped off all the open/bypassed hoses.
There is a small amount of water and oil found in the MAF again, accumulated between his recent work and now.
We agreed some of the issues above are not affecting how the engine is running.
I left there and after it warmed up tried to run it, got just over 2000rpms before it sputtered and the air/fuel gauge dropped to 10.
Bookmarks