suspected vats problem

**37ute** · 03-05-2014, 09:41 PM

Hello all, I am new here and could easily have missed the answer in another thread... My dad is building a hot rod 1937 Chevrolet Ute. It has the drivetrain from a 1997 Corvette and is still under construction. A while back we wired it up just enough for testing purposes to verify the engine would run (it was bought as an unfinished project). After some plugged injector issues it started but would only idle. It was later determined to be a PCM issue which would not communicate properly with the throttle control. The PCM had previously been reprogrammed to remove the VATS, and other circuits not necessary for a hot rod. Once it was determined the PCM was faulty (a hard fault apparently), the company that "rebuilt" it actually replaced it with a different one and supposedly reprogrammed it like the previous one. Anyway once installed the engine will only run for about 3 seconds before it quits. The injector ground side is definitely cutting out which to me means the computer is shutting them down. To me this seems likely VATS may still be active. Because this is a hot rod, there is no security light to blink at me. I did borrow and older Snap-on scanner and there are only two codes that don't seem relevant to this problem (P0522, P1571). The scanner does show some data readouts that may be relevant... PCM IN VTD FAIL (NO), VTD AUTO LEARN (NO), VDT FUEL (OFF). Do these mean anything to anyone. I do not know which software was used for the re-program at this time but I will find out... Internet searches have revealed sometimes the VATS isn't turned off even when the programmer thought it was. I was directed to this site for possible answers and hope this can be verified somehow. Oh and I did unplug the MAF just in case but didn't make a difference. Thanks for your help and direction...

**0rion** · 03-06-2014, 07:04 AM

it does sound like a vats issue. Unfortunately I don't have any experience doing transplants and what you'll need to do to correct it.

**cammed goat** · 03-06-2014, 05:08 PM

You can have a go at this for the time being to see if the engine stays running:

http://www.ls1.com/forums/f6/how-byp...ur-vats-61262/

**37ute** · 03-06-2014, 05:20 PM

In this case, VATS was supposed to be removed from the computer. This hot rod application does not use the Corvette column so there is no original key or need to use the resistance bypass procedure. Hopefully tonight I will get some info on which program was used to change the computer settings....

**cammed goat** · 03-06-2014, 05:24 PM

Keep us posted with what you find.

**Whamhammer** · 03-08-2014, 08:19 PM

I was under the impression that any VATS issue would lead to the car not starting at all?

**37ute** · 03-08-2014, 10:23 PM

From what I have read, engine will not crank when VATS is operating in stock applications. In this case, the starter is wired to a non original switch; and VATS has no control over this. The program used is Tunercats. The original computer was programmed through this and it worked. The replacement computer was attempted to be programmed in the same way but the guys laptop crapped out partway through the procedure. The computer was sent to Vermont to be reprogrammed with the same software, to the same parameters as the first computer. The engine will not stay running with this second computer. To me it sure sounds like the VATS is still active, even though it was supposed to be deactivated... Will post more on this when I have more info...

**cammed goat** · 03-09-2014, 06:56 AM

Computer crapped out as in timed out, or lost power? Hopefully it didn't damage that PCM.

**37ute** · 03-17-2014, 10:07 AM

Dad has decided to continue with the bodywork and has pulled the motor for now. We will get the guy who programmed the computer the first time to retry it when the motor is reinstalled. I will update when that time comes. BTW, I am having difficulty logging into this site. Most of the time it logs me out before I can post anything. Hope it works this time...

**cammed goat** · 03-19-2014, 06:59 PM

OK. Keep us posted.

**37ute** · 04-30-2015, 09:47 PM

Well it has been a loooong time in coming, but finally some good results... Dad has the car 95 percent finished now. The engine is back in and the problem with the running and stalling out issue has been solved. It was in the programming, the VATS was not fully disabled. This caused the engine to stall out after a few seconds when the injectors shut down. This problem was resolved but another cropped up later. The engine would now run continuously, but would not rev over 2000 rpm. It would act like a rev limiter engaged at that rpm. After checking the sensor readings again, I suspected more programming issues. Again it was checked out and found to have some program problems; I believe something to do with "abuse management" parameters being set to low. There may have been more to it then that, but the programmer did not elaborate. It seems to run and rev well in the shop, but has not been road tested yet... This is probably about two weeks away and we are looking forward to it... Will let you all know how it turns out... Thanks, Russ.

**37ute** · 05-17-2015, 10:46 PM

The Ute is on the road and Dad is enjoying it very much! The engine is running just fine after the reprogramming and Dad is enjoying his first fuel injected hot rod...

- - - Updated - - -

The Ute is on the road and Dad is enjoying it very much! The engine is running just fine after the reprogramming and Dad is enjoying his first fuel injected hot rod...

**0rion** · 05-18-2015, 02:39 AM

looks nice.....I'd like to see some other pics of it

**37ute** · 05-18-2015, 09:15 AM

Dad had a lot of fun building what is likely his final full on hot rod project. At 76 years old he is slowing down a bit, but will continue to attend shows and cruises as much as he can.