2005 Monte Carlo SS TSE (59,000mi)

had ZZP powerlog, ZZP downpipe, 180 thermostat, 3.5' modular pulley, CAI, & auto-lite #104 plugs installed.

during the PCM tune the program was run 4x in 3rd gear, all 4x the timing broke-down at high rpm. when this happened the air-ratio went from 11.6, 11.8, 12 down to 6. all 4x it read only 200whp & like 115 torque.

i believe stock the 3800 supercharged engine has somewhere between 192 & 202whp.

the program was then run in 2nd gear, and the engine responded with 224whp & 117 torque with no timing break-down or air-ratio crash

the person doing the tune said in his opinion air was being lost somewhere in 3rd gear causing the timing break-down & air-ratio crash

THOUGHTS / OPINIONS / FEELINGS!!!

 

First thought is that it sounds like it's time for a new tuner. Theyve got access to all of the sensors while its running, so they should be able to see what's happening.

So it started to lean out and then suddenly flooded? Is that AFR correct - 6:1 at WOT?

What does 'timing broke down' mean? Timing went from what value to what value? Direct correlation to the AFR change? Any KR? Engine speed specific or wheel speed specific?

Unless you ran your car stock on that dyno with the same settings, I wouldn't worry too much about comparing to typical numbers. There are too many variables that can cause numbers to be all over the place - type of dyno, smoothing, correction factor, weather data input, etc.

I would've expected it a little higher, but clearly something is majorly wrong with the car or tune given the AFR and timing issues.

This points back to the question on wheel speed. Is it possible they forgot to turn off speed limiter? If it's always hitting at one specific wheel speed, maybe they goofed up disabling it? Maybe it's still opening the BBV?

Air cant just be lost. They should be able to see exactly what's happening via MAP and MAF. If boost is tanking, I'd suspect BBV popping open from the solenoid. Should also see MAF increase rate slow way down.

But being thats extremely entry level stuff to check, if they missed something that simple, I'd be looking for someone else anyways.

 

I think bumpin96monte summed it up in his first sentence. You need a new tuner! Lots of issue do not add up and ALL of these details is what you hired a tuner to setup in the first place. If he doesn't know how to address these issues, well, you need a better tuner.

 

Yeah, my masters degree engineering friend said right off the guy obviously didn't know what he was doing. The "expert" at ZZP was much kinder than you 3 are being. When I was on this form literately like 4yrs ago researching some modest mods to do to my 3800, the #1 thing everyone said was to get the right tuner. Apparently I got robbed $650, as i'd be crazy to go back to the guy. Hard lesson learned!

Here's what the ZZP "expert" said..."It could be a lot of things. Plug gap could be off. It should be at .055. These cars are getting old and the boost solenoid could be failing. It all depends on how much boost you are seeing. If the solenoid is failing it could be bleeding off boost and pushing the bypass open. Your fuel system could be tired and need an alternator volt booster, a fuel pump rewire, the larger alternator power cable, and possibly a new OEM fuel pump assembly. The AFR definitely gets a bit lean. Tuning should be done in 3rd."

I'd say he's trying to sell ****, as he never once mentioned the turner blew!!!

 

Wow, that's a really expensive tune, especially for a bolt on car!



The thing I struggle with on that is it sounds like it falls off so abruptly and harshly. I'd think if gap was off far enough to create misfires that it would get worse and worse with load (and that youd maybe even see signs at the top of 2nd) not just go from firing 100% to missing almost all firings.

Quote:

These cars are getting old and the boost solenoid could be failing.

I do think this is a good place to start. It is possible to delete the solenoid (not the valve, just the electronic solenoid below it). That would eliminate the mechanical failure possibility as well as one part of the tuning speed limiter. Basically free to do, and the valve will still work fine just off engine vac.

Quote:

Your fuel system could be tired and need an alternator volt booster, a fuel pump rewire, the larger alternator power cable, and possibly a new OEM fuel pump assembly. The AFR definitely gets a bit lean.

I'd say he's trying to sell ****, as he never once mentioned the turner blew!!!

Yeah, that does kinda sound like a sales pitch. If the pump is dying, most of that stuff is just bandaids. No way a good pump should need any of that stuff to support a 3.5"

Certainly a possibility the pump isnt in great shape, but I dont understand how youd get a clean pull in 2nd. No doubt 3rd can use more fuel as it's a longer pull and could start adding fuel over time, but it seems odd to have no signs in 2nd at all.

 

Guess he saw me coming. To loooong of a story to tell here. I'm sure your not interested either.

I had found a place called PCM of NC, it's 2hrs from my house in Lexington, SC, so I kept looking. Found a shop, CPR (Charlie Potter Racing) and they have this guy (Chris Waters) that comes in and does tunes, the shop let's you know that it is separate, even though tuner was wearing one of the shops sweatshirts. Paid 2 different bills. The shop only does maybe 5% street cars from what I saw.

The tuner guy said he did a street tune before I got there, he found my #5 plug wire was bad.

To put it bluntly, i can only pay to have the work done. So, I start off with taking the car to a new tuner? Hope this guy Chris i had do the tune just plain suxed! Or at least with a qualified tuner i find out what is wrong, and get it fixed?!

I don't know if it's alllllll in my head, the cars seems to be quicker.

btw...I can't believe you can't type the word sh*t on this form...

 

The thing I'd be worried about with just going straight to a new tuner is that I'd be worried theres a legitimate maintenance issue that needs to be corrected first. Youd hate to pay for a tune only to have them get partway through and have to stop so something can be fixed (especially some as big of a PITA as a fuel pump).

I guess I'd suggest having someone do diagnostic first on the 3rd gear pull to analyze why its breaking up. Between a scan tool and some simple mechanic gauges, they should be able to verify the cause is not something mechanical or electrical.

Once any issues have been corrected, then it would make sense to have the tune checked. Given your situation, I'd probably consider just buying a canned PCM tune from a major 3800 vendor and being done with it. The engine isnt that heavily modded to really NEED a custom tune (although of course the results will be better if properly done). I just dont think I could personally swallow spending another $400+, especially if the next place isnt really a known 3800 shop either.

 

I have dealt with PCM (Piedmont Custom Motorsports) in the past. They are known for Mustangs and Ford engines. For Fords and Mustang, they are someone that I could recommend. For the 3800, I am not sure. I really don't remember seeing any GM cars in their shop (but I have only been there a couple times a few years ago). In this case, I would recommend you have a conversation with them regarding their experience with the 3800 before using them. Do they really know what they are doing with these engines or are they just trying to branch out into that area.

 

Well, off to get diagnostic work done. Thanks for the advice Bumpin, i'm basically positive you were one of the people that reached out to me 4yrs ago when i was on here. This car was off the road those 4yrs actually. I would start it and drive around the block every 3 to 5wks, let it run for 30-40mins. Just under 60,000mi. Doesn't mean it can't need a fuel pump or solenoid though. I was just looking for 25-45whp increase.

JACKDW: PCM of NC has a GM performance parts section on their website, photos of Camaros & Vettes they've done. Anywhere I go though, i'll investigate a whole hell'va lot more this time FOR SURE!!! (lots of questions)