HELP! "stock" CTSV lots of KR and SLOW!

[happysem]

Why can you not just copy all differences from a stock M6 file with the same OS? Would take about 3 clicks and 15 seconds.

I changed all the normal parameters to stock, but it doesn't look like I can see what would be in the stock DTC list.
The whole thing comes up blank when I open any file that isn't the one I'm editing?

EDIT: just double checked, if you do it in 1 session of VCM editor and look at a comparison file, it won't pull the list, however if you open 2 instances of editor, you can compare side by side. Those I posted are normally turned off it looks like. I'm just looking for other stuff while I'm waiting for good snips to come in to make the access panel hole this weekend to check the pumps and lines on the top of the fuel tank.

[blindsquirrel]

Open file, open compare file, 'View Comparison Log', right click 'copy all differences'.

[happysem]

Open file, open compare file, 'View Comparison Log', right click 'copy all differences'.

Ahh thanks, I found comparison log earlier but didn't know of that function and I see DTC listed now. Just wasn't sure if it would work since I couldn't see/scroll through the whole list.

Got my wideband out of my vette and put the V on the lift.

Its got a gas leak on the passenger side tank, somewhere near the top, looks significant. Wonder if that's why its losing some flow? Can't really see it from under so I'll get the access panel going this weekend and hopefully be able to see better.

[mememe123]

It might be the plastic elbow on top of the hat. You'll have to drop the whole rear end or cut a hole up top.

[happysem]

It might be the plastic elbow on top of the hat. You'll have to drop the whole rear end or cut a hole up top.

Yup, that's exactly what it is.

Can't find the aftermarket hat that isn't on backorder, but found a new pump assembly for about $300 on summit, so at least that whole section will be new.
Not sure if there's an easy way to test each pump individually, if the second one is failing or what, but grabbing the whole assembly and 2 new pumps seems to be a logical choice for $300.
I'll keep my old hat and modify that one with a better fuel fitting if/when the other one breaks.

For funsies, I hooked up my wideband. Car gets a solid 17-17.4 WOT, only did it for a second obviously. So all the data from the logs is correct and the O2s are good. Its literally as lean as can be. Can't believe it survived this long.

Hopefully its just bad pumps with no CEL for some reason, but I'll check the lines...after that its gotta be injectors or FSCM maybe.

[PGA2B]

Holy crap! What is your PE set to? I'm not sure which tune you have loaded.

[blindsquirrel]

Logs show it commanding 1.28 like the tune is asking for.

[PGA2B]

Then that should be .78 Lambda (which is about right) not 1.16 to 1.17ish lambda (17 to 17.4 AFR) that he said his wideband was showing.

[blindsquirrel]

It's commanding rich but O2s are flatlined lean, because of a fuel supply issue.

[blindsquirrel]

Hopefully its just bad pumps with no CEL for some reason, but I'll check the lines...after that its gotta be injectors or FSCM maybe.

If it's lean enough to not make any power, it can't really hurt itself. The danger zone is when it's still getting enough fuel to make good power but not enough to keep things from melting.

[PGA2B]

If it's lean enough to not make any power, it can't really hurt itself. The danger zone is when it's still getting enough fuel to make good power but not enough to keep things from melting.

Good point. Couldn't get over how lean it was at WOT.

Looks like Adam (ALM) is out of fuel hats right now. He is Adam112 on the ctsvowners.com site.

https://almperformanceanddesign.squa...nsrx2o5qsjhl90

[happysem]

Current tune is 100% stock, feels very slow and thats what got the 17+ AFR at WOT.

I'm curious, but I don't know if it really matters at this point what the original tune in the car would have done WOT, since it felt fairly normal to me for a stock V.

Ordered a fuel pump assembly, but I won't be able to install it for about 3 weeks while I'm out of town.

Really appreciate the help fellas and I'll be sure to update when I get back

[DMDay]

E85 is very dirty 🤔

[DMDay]

did this ever get sorted?

[happysem]

Update, unfortunately this has not been resolved yet.

The fuel pump assembly I ordered was wrong, looks like the only real "V" one is the $1500 version, not liking that option. Sent that back because it was actually for the V6 car.

I finally got an ALM hat in, and had some issues with it, but got that sorted out. Installed, no leak, car fired right up.
Runs normal, but as soon as you get into the throttle, its lean as it was.
Decided to add a ton of fuel in PE to see if it would get it. Went from 16.8 AFR (only staying in it for a half second obv) down to 13.8 but couldn't get more fuel no matter what I tried.

Drove it around for the day just to see what it would do, drove normal otherwise. Then it started stalling, hesitating, and literally wouldn't go above like 10mph. Got stranded, wouldn't restart. Put it in the trailer.

FINALLY got some codes out of the car, not sure why it took this long... P069E, P2635, P0191, P0171, P0174, P0300, P0302.
At this point, I pretty much gave up. Tried calling Jeremy at FasterProms to just give the car to someone smarter than me and let them sort it out and mod it so I don't have to touch it again, but couldn't get a hold of him.

Unfortunately, I will be unavailable to work on the car for about 2 months, so its going to sit there.
I did order another FPCM, but no dealers near me are able to program it in a timely manner, but I'm going to try there next.


At this point, maybe the fuel pumps are bad as the code says? But I tested them as I could while it was out of the car. Both of them when given 12V made the same noise, and spurted out some fuel.
Maybe the FPCM is bad and not telling the pumps to give the commanded amount of fuel?

Not sure what to do, I'll try to get the FPCM programmed and installed and see what changes.
I will definitely update the thread with whatever the fix is, if I get it fixed before I just walk away from the car and put it up for sale lol.
May be a couple months.

[blindsquirrel]

Inspected for kinked/pinched fuel lines?

Checked the injector inlet screens? I've seen some really weird shit with those, like a coating in the tank came loose and made it all the way to the injectors, somehow. This was mostly on mid-2000s trucks and I got out around that time, never found out if it was a tank issue or something with fuel quality.

[happysem]

Minor update.

Tried calling multiple performance shops in/around GA area, people suck at getting back and answering questions.
One shop did give me a rough diagnosis and bet the fuel pumps were actually bad. Tried to talk about getting it fixed and doing mods, then they just stopped replying. Wonderful.

Replaced pumps on my own with AEM 50-1215's, found some threads about them being the best option to stock pumps and are 100% plug and play.
Car fires up, but still won't get any more fuel. Verified wiring to both pumps is good.
Played around with HPT turning off injectors 1 by 1 to hear difference in idle to make sure they're all firing, checks out.

Ended up giving up and trailered it to a local Cadillac dealer, they say the injectors are losing pressure?
Of course the service tech that answers the phone can't actually answer intelligent questions when I ask what's the difference between rail and injector pressure to confirm they are actually bad.
Quoted me $2200 to get injectors replaced after the diagnosis, but they aren't 100% that it's the only issue, just that it's the one that needs to be solved next.

Hate ordering more stock parts with no room to grow in the future if I keep the car, but I think that's the best option at this point. Under $500 for ACDELCO on Amazon.
Will probably install them myself and save $900+ in labor. They also say they need to reprogram the ECM/FPCM for new stock injectors? Not sure why...of course he didn't actually answer why when I asked.
I'm assuming all I need to do is force the computer to relearn short/long term fuel trims? They already reset it all back to 100% stock (even though I believe I had a stock file on the car when delivered).

Blindsquirrel, checked as far as I could up and down the car and nothing is kinked/pinched or leaking at this point.
Will see how injectors look when I pull them out.
Probably give some update this weekend.

[happysem]

Minor and probably final update.

Dealer wasted my time and money for a month.

First diag was that the injectors were losing pressure and they needed to be replaced, but they couldn't guarantee that it would do anything, but that I had to pay to get it fixed and see what happens.
I bought ACDelco injectors from Amazon, swapped em in for $500 myself (instead of the $2200 dealer charge) in about an hour. No change at all to the car.

Then I brought it back to them, we decided to reprogram a second FPCM/FSCM that I had bought earlier. Had them do it since I can't do that myself.
No change.

Then I brought it back to them again for another diagnostic, they said throttle body, I asked what specifically, they couldn't really tell me. Bad service advisors and managers.
Talked with the tech, he said he was getting wild throttle reports in his testing. They quoted me $900 for TB/TPS + install. Again, no guarantee it would do anything and that I had to eat the cost.
Bought a Dorman TB with TPS off Amazonfor $100, installed myself in Caddy parking lot in 10 min. No change. Even did the throttle re-learn.

Left the car with them for a week, they swore they would work on it again. Called multiple times, then just showed up on Monday pissed - they didn't do anything at all.
Trailered the car back home. I'm at a complete loss with this one.

TLDR; the car will not get fuel at WOT. It stays at 16-17AFR (1-2 sec run, not trying to blow it up), O2s read dead lean as well. It makes boost and goes through the RPM range cleanly. TPS looks normal, the car is just slow.
Not sure if HPTuners actually recognizes the secondary fuel pump for these cars but that parameter says it never turns on.
Car runs fine otherwise now. No codes currently. It has new fuel pumps, injectors, TB/TPS, and reprogrammed FPCM/FSCM. It had an aftermarket "tune" but we reset everything to stock.

My last ditch effort is probably to power both pumps directly with 12V and see what happens by essentially bypassing the FPCM/FSCM.

After that, I'll probably just put it up for sale as a loss. Unsolved, sorry if anyone ever finds this thread and a similar issue.

[BigTuner]

Minor and probably final update.

Dealer wasted my time and money for a month.

First diag was that the injectors were losing pressure and they needed to be replaced, but they couldn't guarantee that it would do anything, but that I had to pay to get it fixed and see what happens.
I bought ACDelco injectors from Amazon, swapped em in for $500 myself (instead of the $2200 dealer charge) in about an hour. No change at all to the car.

Then I brought it back to them, we decided to reprogram a second FPCM/FSCM that I had bought earlier. Had them do it since I can't do that myself.
No change.

Then I brought it back to them again for another diagnostic, they said throttle body, I asked what specifically, they couldn't really tell me. Bad service advisors and managers.
Talked with the tech, he said he was getting wild throttle reports in his testing. They quoted me $900 for TB/TPS + install. Again, no guarantee it would do anything and that I had to eat the cost.
Bought a Dorman TB with TPS off Amazonfor $100, installed myself in Caddy parking lot in 10 min. No change. Even did the throttle re-learn.

Left the car with them for a week, they swore they would work on it again. Called multiple times, then just showed up on Monday pissed - they didn't do anything at all.
Trailered the car back home. I'm at a complete loss with this one.

TLDR; the car will not get fuel at WOT. It stays at 16-17AFR (1-2 sec run, not trying to blow it up), O2s read dead lean as well. It makes boost and goes through the RPM range cleanly. TPS looks normal, the car is just slow.
Not sure if HPTuners actually recognizes the secondary fuel pump for these cars but that parameter says it never turns on.
Car runs fine otherwise now. No codes currently. It has new fuel pumps, injectors, TB/TPS, and reprogrammed FPCM/FSCM. It had an aftermarket "tune" but we reset everything to stock.

My last ditch effort is probably to power both pumps directly with 12V and see what happens by essentially bypassing the FPCM/FSCM.

After that, I'll probably just put it up for sale as a loss. Unsolved, sorry if anyone ever finds this thread and a similar issue.

When my ZL1 had low fuel pressure issues it was the fuel pump, car would run perfectly fine until WOT where it would drop to 30 psi and go lean. You need to replace the pump I am almost certain that is the issue, sucks that it is $1500 for the CTS, was $261 for the ZL1. I would have bet it was the pump even before you went through and ruled out everything else, $1500 is still less than you would eat selling it non running. Also those are PWM pumps, you can't just run 12v to them, there would be no control over fuel pressure, the fuel pressure is controlled by direct control of the pumps.

[gtstorey]

Maybe use a mechanical or secondary gauge to determine fuel pressure at WOT?