It'sOver9000!!

So I took some of Sydwayz's advice and decided to let Speed Inc. know about my findings with the Throttle Body earlier today, before having used EFI Live for screenshots (which was supposed to happen yesterday but those plans fell through, so that still hasn't happened).

They responded by saying the next thing to check would be the connector to the throttle body to make sure it's getting a good connection and that there's no physical damage. But this time they also mentioned that if I brought the car in and they couldn't find anything mechanically wrong, they would have their tuner go into the programming to find the cause of the malfunction.

When I asked about cost, I was told that there would be no diagnostic charge at this point, which for me is a major relief. Just a charge for parts/labor for any mechanical issue unrelated to the tune and work for H/C and Clutch. They also agreed to inform me of anything they found, and let me do the labor if it's unrelated (as I have already invested a lot into this project, so saving where I can helps).

It's amazing how far polite conversation (and doing some leg work on your end i.e. swapping TB's for diagnostics) will get you. I'll be taking the car in tomorrow morning, and then I guess we wait.

I'm just wary of how focused they seem to be on finding a mechanical problem and not looking at the tune first, when almost everything I've read points to this being a tune issue for that Calculated vs. Actual airflow table from the P1514 code. I will remain cautiously optimistic and hope that their reputation as an honest shop that stands behind their work will be true. I just don't want to get taken for a ride.

mrmagloo

I'm just catching up, but would have gladly let you borrow my TB being local. After reading the entire thread, I too was put off that they immediately pointed a finger, instead of just saying to bring it by for a looksie. No doubt, you dropped a good chunk of change, and that wasn't the best initial response, Imho. Sucks, that you had to prove him wrong before he gave you the kind of answer you should have got in the first place. Hopefully, this will get settled quickly for you now.

Clancy209

Did you read your dyno tune? If they told you to take it easy, how did they do a dyno tune

It'sOver9000!!

I took it easy for the first 300 or so miles because I had a new clutch installed at the same time. They said it was okay and that they can dyno tune with a new clutch because they only do pulls in 4th gear and have done it many times before. The bigger issue as far as I know is that you're not supposed to bang through the gears and drive super hard until the clutch is broken in. Hence why I took it easy for the first 300 miles.

It'sOver9000!!

You are so kind, thank you for even offering to help with the TB

Fingers crossed that the situation gets resolved quickly and painlessly. How they handle it at this point will determine if I give them future business when I decide to finally get a supercharger.

ParisTNDude

This is going to sound really stupid, I know. I put headers on my 02 in the garage and on my maiden ride the same thing happened to mine. I went home and searched and searched for an answer and found it. One person said, "this is going to sound stupid, but...." He told me to check my spark plug wires to see if they were securely fastened, and on one of them, it was loose. I clicked in place and the problem went away, never to return.

Beyond that, I don't know.

00__Vette

Just read the entire thread! I just had my car worked on and got it back yesterday. If I had any issues with it, I feel as confident as possible that they would make it right on all accounts.

Obviously, if the car has unrelated issues.. they shouldn't be responsible for fixing that for free.. but I think your in agreement. However, I was very disappointed to hear that they dismissed the tune so quickly instead of saying "bring it right back, and we'll find out what is wrong and fix it". After spending a **** ton of money, that is exactly word for word what I would expect to hear from the shop.

Good luck tomorrow! I'll be checking back to hear back on your progress. Sending good luck your way

Route99

Interested in your outcome.

It'sOver9000!!

No stupid suggestions here, but I'm surprised you'd get the P1514 code from a loose spark plug! Not sure how that would work...

I just checked my wires and all seems good there!

It'sOver9000!!

Absolutely agree. And I'm glad they're okay with doing the diagnostics free of charge, and if it happens to be an unrelated issue, to let me know the problem and let me handle the labor on my own.

Thanks for the good wishes, hopefully it's as simple as updating a table in the tune.

Bill Curlee

Before they retune it, I would make absolutely positive that ALL of the ducting between the MAF and the TB was secure and not leaking any air.

I would also clean the MAF Sensor with MAF cleaner to get a good base line with a properly metering MAF. They do get dirty over time and that dirt effects its sensitivity.

You probably saw how dirty your Throttle Body blade was.

Bill

It'sOver9000!!

Brought the car to Speed Inc. this morning. Got an email a couple hours later saying the tuner drove the car and was able to hit WOT without going into limp mode. Go figure.

Sometimes I think cars do this on purpose, where they show symptoms to the driver but then decide to behave with the mechanic, solely to annoy the owner.

Hey, ParisTNDude... maybe checking the plug wires solved it, since that's the only thing I did last night even though they were all snug and I don't think they're related to the P1514 code

Anyways, Speed's been really good about communication so far and at least they mentioned that they DO believe my story... plus they see the P1514 code in the computer's history. Now they're thinking maybe it's an intermittent issue and that will take some time to diagnose. I offered to come by and drive the car thinking maybe it's something with my driving style, but I was told to hold off at the moment and that they're gonna put the car up in the air for a closer inspection first.

*sigh*

Jeff T.

I hope they can sort it for you!

Russ K

The P1514 code/limp mode is caused when the actual airmass exceeds the P1514 table values in the tune. Stock is .76 g/cyl, and your probably hitting .9 g/cyl.

I would raise the stock P1514 table to be about 10% higher than your actual airmass. What is your altitude? As the lower the altitude, the higher airmass.

Russ Kemp

It'sOver9000!!

First, and most importantly: Since I got the car back last Friday (9/27) I've been able to hit WOT without issue, and boy is it a ton of fun now!
Now, for the... interesting... version of this story (*disclaimer: I am not intentionally bad-mouthing anyone, just laying out the details as they happened, y'all are free to make your own opinions ):

- Dropped the car off last Wednesday, 9/20.

- Got an email a little later the same day saying the tuner took the car out and was able to hit WOT no problems. They're not sure what I've been doing to set the P1514 code and limp mode. Might be an electrical issue since C5's are notorious for those, so they'll look into it. They do believe something happened though, since P1514 was in the history.

- No further contact until Friday 9/27. Got another email saying the car was combed over, grounds checked, etc. and no issues found. They logged more WOT runs with another tech, and found no issues. I came by later, drove the car myself with someone and I was able to make WOT runs myself no problems. Didn't get charged diagnostic fees, and I took the car home. Was told if the issue comes up again, bring it back.

- Before dropping the car off for diagnostics, I managed to save a copy of the tune through EFI Live. After bringing the car home on Friday 9/27, I saved another copy of the tune. Upon comparison of the before and after, I see that updates were made to some of the parameters. Most interestingly, the C6101 and C6102 tables were updated (predicted airflow, which I mentioned at the very beginning of this story). The values are now maxed out to 4095.9 mg/cylinder.

- There was no mention of the tune being updated, and I emailed the shop back today to let them know of my findings. The response I got is that the tuner tried and was unable to duplicate my issue prior to updating the tune, but decided to modify the tune anyways to potentially fix the issue in the future. I was also not notified of the update to my tune because these changes "are not the definitive fix to this unknown issue."

At the end of the day, the car now works and I wasn't charged diagnostic fees so... I can't complain in that regards. But, it's still really strange to me how I was able to produce limp mode every time I tried to hit WOT, but now the shop wasn't able to replicate it at all and my tune gets updates to the SAME TABLE (C6101) I mentioned when I first informed them of the issue.

Also interesting is that I was able to compare my C6101 table with that of my friend's stock C5Z. My predicted airflow values in this "old / pre-diagnostic" tune are either the same or LOWER than his... which doesn't make sense given that with my mods (LT Headers, CAI, Heads, Cam) my predicted airflow values should be HIGHER, because my engine is taking in more air... right??? Will be posting this table from the old tune and responding to Russ K after this.

I suppose I COULD flash the "old" version of my tune back onto my car to see if I can repeat the issue to confirm whether the C6101 updates turn the issue ON/OFF, but that's the test engineer in me. Not sure I want to do that and repeat limp mode, it's super freaky when it happens. First time it happened I nearly crapped myself because it feels like hitting a wall.

But like I said, it seems like the car is fixed and the shop did "fix" the issue without charging me. They were also very polite to work with (as was I, kindness and respect go a LONG way towards having adult conversations) and the car does drive well now. I just want to know if updating the C6101 tables is really what solved this issue!

It'sOver9000!!

Right on, I saw your response in several older threads on the same issue and that's what got me looking into it when I first made my own thread and talked to the shop.

I'm attaching a screenshot of my C6101 table that has the values on the tune BEFORE I gave the car back to the shop for diagnostics... do these values look right for a car with LT Headers, CAI, Heads and Cam?? Could this actually be the cause of limp mode at WOT for my vehicle?

1999corvettels1

Probably best to just leave it alone and enjoy the car, now that is running good.

acuevo

Hey I'm glad its running perfectly now! I'm not familiar with the tables though so I can't say whether what you have there would be considered normal.

Russ K

That table is 100% stock. Of coarse that would cause the P1514 reduced power with your mods.

Russ Kemp

It'sOver9000!!

LOL.

Guess I have the answer as to what caused my issue, regardless of whether the shop admits it.

Unfortunately this does leave me with some more questions, but... not even sure it's worth pursuing. Car seems to run fine for now though, so just hope something else doesn't happen. And hopefully this thread can help someone else in the future facing similar problems!