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View Full Version : What a mess this Caddy is in



teamzr1
04-11-2020, 03:26 AM
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.

In-Tech
04-11-2020, 06:00 AM
Post the .cal file. When many shops have been in something I generally just throw their calibration away and start with a stock file(Actually 99.9% of the time I toss the garbage, it's not worth the time to hunt through someone elses crap). I usually just buy one from John for $40, give him the vin and later shows up the stock .cal via email. GM has the SPS for $40 too but I just order from John to support him.
The water and oil in the MAF has to be addressed immediately or time is just being wasted. Do you know what injectors? What style maf and/or tube diameter and shape?

Can you post some pics of the turbo setup along with as much intake tract as you can?

teamzr1
04-11-2020, 07:47 AM
Post the .cal file. When many shops have been in something I generally just throw their calibration away and start with a stock file(Actually 99.9% of the time I toss the garbage, it's not worth the time to hunt through someone elses crap). I usually just buy one from John for $40, give him the vin and later shows up the stock .cal via email. GM has the SPS for $40 too but I just order from John to support him.
The water and oil in the MAF has to be addressed immediately or time is just being wasted. Do you know what injectors? What style maf and/or tube diameter and shape?

Can you post some pics of the turbo setup along with as much intake tract as you can?

This caddy is not local to me so cannot take photos
Owner has to deal with the oversized inner cooler that was used at the time had larger dual turbos and then smaller ones were installed
add they are located in ass end means then by the time turbo pipes return back to front where inner cooler is causes some condensation
which then of course will pass through the MAF

Injectors are larger but would have to go back and look at the injector flow table to see what they are.

Attached is the existing tune that is unknown who did it

MAF I recall is stock, do not know offhand what size airbridge is

Existing calibration in PCM uses a Tunercat 57_05 VDF

In-Tech
04-11-2020, 10:40 AM
Hello, thanks for the .cal If you order a copy of the stock vin cal I would like a copy if you don't mind. According to what I can see on the internet it uses a cartridge style MAF so the tube it is installed in is critical and can definately require some adjustment to the MAF transfer function. Pics of all of the inlet would be helpful. I assume we don't know anything about the valvetrain when it was converted to a 4.6L? Also need to check what MAP sensor it is using, the cal shows it to be a 2 bar. The cal says it is a 5 spd automatic, is this true? Glad to see it has an e67 ECM.
Do we know the approximate hp level of the engine? Definitely need to know EXACTLY what injectors are installed, the .cal shows ~42lb but table doesn't look stock and the MAF table is fubar. The VE is turned off in the cal too.

Anyway, it's all fixable :)

kur4o
04-11-2020, 12:43 PM
I compiled a stock file based on the vin and a generic e67 bin. All looks good except the eeporm data is from the generic bin.

Enjoy.

In-Tech
04-15-2020, 01:30 AM
Hi kur4o,
Yes, the format looks great. Just like you said though, the calibration is not for his application but if you had nothing, it could be adjusted it looks like.

teamzr1, any updates?