GOTHAM VETTE

Essentially, I installed a new motor, ran the car for a few brake in miles, and had the car tuned by a very reputable tuner without incident. But as soon as I got home and went for a drive the car it's running like crap.

There are no codes other than a MAF one that needs to be tuned out after switching to a 2bar setup that I've put in place after this problem began. But the car is idling way to low, way to rich, and the headers start to glow after running for a couple of minutes. I've checked the timing on my scanner and am seeing around 23 degrees.

I'd imagine a sensor has failed but without a starting point to start looking I'm hoping that someone can point me in the right direction.

.

Steve@C56

So... after tuning and dyno, you come back home without issue, right ?

The MAF change was BEFORE dyno ??? (so, the tune is with 2bar hardware but with 1bar software)

What is your exact MAF code ?
What is the idle value for MAF with the scanner ?
What is the command AF ratio ?
What is the real AF (if you have wideband) or what is your mV for front02 right and lelf ?
What is your Long Term Fuel Trim and Short Term Fuel Trim ?

FWI 23 degrees can be normal value for idle

Pekka_Perkeles

Bring it back.

As simple as that.

Everything else is just guessing.

4DRUSH

Bingo

stryderss

ditto on the taking it back

Milan

Every SD car has a maf code, it's that code that puts you in speed density. Any other CELs?

How do you know it's running rich? If the headers are glowing it's probably too lean, not too rich.

GOTHAM VETTE

Hey Guys, normally I would take it back to where I had it tuned but I was very unimpressed with the response I got from them and would rather sort it out myself or go elsewhere if I have to.

The problem started immediately after I got back from having the car tuned. Thinking it was something that was done during the tune, I pulled the ecm and had it retuned and it was at that point that the car was converted to a SD tune.

Here's what I've pulled with my modis scanner.

Only code present is P0103

ST fuel trim fluctuates B1 -4 to -5 and B2 -3 to 0
LT is 0

Front O2's fluctuates B1 200 - 840 and B2 178 - 864

MAF g/s17-19
Hz 4000-4100

Timing is sitting around 21-23 at idle.

There was a difference of about 20 degrees between my temp being displayed and what I saw with my temp gun on the head, so I've replaced it without much difference.

stevieturbo

If the headers are glowing, you can be damn sure either it's incredibly lean, or the timing is NOT 23deg.

What is commanded or displayed on a screen cannot always be assumed is what is seen at the plug which is what matters.

So whilst it should be correct, given the major problem you're having, do not assume it is correct.

Be very careful driving in this state or you could end up doing expensive damage.

GOTHAM VETTE

Another nice little update

Up to this point the car has always fired right up. Now it won't even offer to fire!! How the f*** can this not be throwing a code??

stevieturbo

You could remove a cylinder head and still not throw a code...

Lots of problems will not throw codes.

Onboard diagnostics are not the be all end all. There are many non start scenarios that wont throw codes. Hell could even be no fuel in the tank.


Glowing headers, possible wrong timing...non start. A lot is suggesting crank trigger issues.

Milan

Car isn't in reduced power mode by any chance is it?

Maybl8r

When you had it "retuned" did they build an sd file on the dyno? When you convert to a 2bar sd file, all the data is at a max setting. Data has to be copied over or added to make the car run. At least in my case it did.

BLOWNBLUEZ06

Car would never have started with the default file loaded.

BLOWNBLUEZ06

You must've disconnected the battery or reset the PCM somehow. The car won't start until the MAF fails. Once the MAF fails, it'll start again. How easily it fails depends on how it was set up when it was tuned. We'll talk tomorrow and get this straightened out in the end.

Steve@C56

P0103 code is normal when SD

STFT -5/0 tell good fuel tune (for idle/cruise), not lean, not rich

LTFT is 0 tell perhaps LT disable (not a problem because STFT are good)

O2's 178/864 tell normal activity (for idle/cruise)

Timing 21-23 at idle can be normal

So, reading say not rich, not lean, correct timing...

As BLOWNBLUEZ06, try to disconnected battery and wait 5mn

sfc rick

I have a question? Why the heck are YOU trying to fix a broken car that was tuned by a shop?

The only reply you should be seeing here is.....wait for it.........TAKE IT BACK AND MAKE THEM HONOR AND WARRANTY THEIR WORK!

That's why you paid so much money for the tune!

Pekka_Perkeles

I'm trying to read between the lines: is it because you did the build by yourself and not the shop?

Of course I may be totally wrong. And you don't have to reply; that's just fine.

stevieturbo

They didnt build the engine or install it I presume, so until a proper diagnosis and cause carried out...perhaps a bit premature to point fingers.

But certainly the "tuner" needs to have some input towards a resolution.

DOUG @ ECS

You have trims showing correct, and timing showing correct, yet glowing headers. You have a mechanical issue that's not related to your original tuner IMO. Then I sent you a base start up file and you have the same issue, so one dyno tune, one base file, and same issue.

Find your mechanical issue, then get final tuned.

DOUG @ ECS

His original shop tuned the car, that does not mean they are now responsible for every ounce of that vehicle from then on, they are responsible for the tune ONLY. Naturally shops are there to help, but when you build and install an engine, then YOU get to figure out the problems, just like a shop would if they did it.