Attempted my first startup today. Engine tries to fire, disengages the starter, and dies. Runs for less than a second. I did get it to start and run for about 6 seconds once, but then found a pint of Gas on the garage floor ( quick disconnect had popped off the fuel rail). Tested fuel pressure. Pressure starts at 40, drops to 38 when power is disconnected and holds pressure for about 10 minutes, slowly dropping down to about 20 psi. As part of the conversion, installed new AC Delco EP381 fuel pump. Tried starting with Fuel Pump manually engaged ( via ALDL), but no start. Tried starting using Flooded procedure, in case it was flooded, per service manual input, but again no joy. I verified that the plug wires were correct, and that the IGN Module was plugged in.
Maybe I didn't get VATS properly programmed out, although it did start and run once?
Background: Engine is a 95 Series 1 out of a Riviera. Using Riviera Harness ( modified) and Riviera ECM ( 16183247) ( OBD1.5 style). EGR and Boost are still installed on the engine, as is Purge Solenoid. Wanted install to be as basic as possible. I ran the engine while it was still connected in the donor, and downloaded a baseline of running info using TunerPro RT. I copied the Riviera base BIN (BKZS) into TunerproRT, and used XDF $5B L27 L67 3.8 to modify the Bin for VATS. Only changed made to initial trial BIN was to "uncheck" VATS Diagnostic ( Error 626) and Vats Select ( also unchecked). Saved the BIN, and programmed new chip. Verified chip against original file, and found only the two changes. Also tried burning another chip, with same results.
Are there any other changes required in programming? I did not do anything with the Theft Deterrent Fuel Enable wire at the ECM (WD14, Dk Blue), Per Sinister's instructions.
If the programming is OK, where else do you think I should start troubleshooting.
As always, your help is much appreciated!!
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
Tried unplugging the MAF, but same result. Tries to run, then dies quickly. If I keep the pedal to the floor ( Flood Clearing), then it will keep cranking as long as I hold the key ( maybe irrelevant).
Harness was pretty much a complete re-wire, eliminating all unused wires. I did buzz out each connection after it was finished, from ECM to each sensor, etc... Doesn't mean that I couldn't have gotten something wrong, though
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
OK, tried a few things this morning with no success. Finally got TunerPro RT to connect, and read the codes. Had VATS code 629. Cleared the codes, and tried starting, and immediately the VATS Error popped up again. So now we know the problem- VATS. I've verified that the VATS Enable flag is unchecked ( checked= Enabled). Verified the BIN against both the Stock download and another 3800SC bin, and both showed the primary difference was the VATS Enable flag, so I think I've got it checked properly, but IDK..
Your thoughts and ideas?? I guess I could add a VATS bypass module, but it seems redundant if I have the capability to program it out ( maybe I don't have that capability-apparently! ).
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
OK, tried a few things this morning with no success. Finally got TunerPro RT to connect, and read the codes. Had VATS code 629. Cleared the codes, and tried starting, and immediately the VATS Error popped up again. So now we know the problem- VATS. I've verified that the VATS Enable flag is unchecked ( checked= Enabled). Verified the BIN against both the Stock download and another 3800SC bin, and both showed the primary difference was the VATS Enable flag, so I think I've got it checked properly, but IDK..
Your thoughts and ideas?? I guess I could add a VATS bypass module, but it seems redundant if I have the capability to program it out ( maybe I don't have that capability-apparently! ).
If the VATS Enable Flag is unchecked, then it should be turned off and the PCM should no longer be trying to cut injector pulse in response to a missing VATS signal. HOWEVER, this will NOT prevent the two VATS-related DTC's from setting in the PCM. You will have to disable those codes separately (626 and 629).
I do not think your issue is VATS related. But it could be caused by so many different issues, it's impossible for me to pinpoint the problem right now.
That being said, I did want to mention a common issue I've encountered with EFI engines in general. When they sit for a while, disconnected from a fuel system, the fuel in the injectors likes to dry up and leave behind a residue that clogs up the injectors. It sounds like this could be your issue. I would recommend you pull the fuel rail and injectors up out of the engine, place rags under all of the injectors, and crank the engine over a few times to see if all injectors are spraying fuel. Be sure to have a fire extinguisher handy, just in case. If all injectors are not spraying fuel while cranking but some are, then you either have a wiring problem or you have some clogged injectors.
Originally posted by Darth Fiero: If the VATS Enable Flag is unchecked, then it should be turned off and the PCM should no longer be trying to cut injector pulse in response to a missing VATS signal. HOWEVER, this will NOT prevent the two VATS-related DTC's from setting in the PCM. You will have to disable those codes separately (626 and 629). .
Thanks for the input. I'll try testing the injectors tomorrow. Just to clarify on the VATS, when I have programmed it out on other ECM's ( '165 ECM, TPI engine), all I needed to do was un-check the Vats Enable flag. Is there any more info I can find on how to "disable" the codes separately. I know how to "clear" them ( disconnect power), but I guess not how to program them out. Maybe not available in TunerPro?
I delved a little deeper into TunerPro, and the only place where I find I can modify Errors, Switches, etc is in the ADX file. I can see how deleting these items here would keep me from seeing them on the data output, but don't think that this is the correct place for changes ??? Guess doing this once every few years is just not enough "practice". Also, I think my Computer Science Degree is probably "outdated". We still used punch cards back then!!
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
If you had a degree in computing then you should now how to "read" hex. Something I never went deep into myself. All that aside. I have had issues with Tuner Pros. files. Some of the more obscure PCMs may have small glitches and the file and sometimes the address for the function is wrong. When first changing things for the 1993 3800 PCM I had found that the Tuner Pro file had a few odd numbers in the timing table. I ended up using another editor, but still used Tuner Pro to view. I had to use the non S/C file to view it correctly. You may want to hunt around and try to find what hex address that the Vats flags are under and make sure that address is what was changed. The other editor I used is an old DOS based editor. It was very hard to find the files for my PCM to work with it. You PCM being more obscure, would most likely be harder to come by. By the way, where were you getting your EEproms from. I have 2 SST s7sf256 EEproms for mine and they are getting hard to find non counterfit.
Chris, I had 1 semester of Assembly Language, and I hated it. That was 45 years ago! Damn, can't believe I'm that old! I did spend a couple of hours earlier today looking at the HEX code, and did find some discrepancies in the locations of the VATS parameters when using two different XDF files, but I'm not sure if that means much. It all depends on who made the XDF mask, and how it was set up, and I'm not even going to pretend I know what is going on. I agree with you that the XDF files are a little sketchy, especially on this ECM, and that may well be the issue. I found another thread with similar issues - he was even using a VATS bypass module and having no luck.
I'll test and clean the injectors tomorrow, and if that doesn't clear it up, I may post some questions over at Moates.net to see if they can help on the programming. I'll also be entertaining any other suggestions for troubleshooting that the more experienced members here might suggest.
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
Chris, to answer your question regarding proms, I'm using SST 27SF512-70-3C-PG. Easily found on Ebay. To program , use file size 64K, Buffer start 000000->00FFFF Chip Start 000000 -> 00FFFF
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
SUCCESS!!. I kept digging on the XDF file maybe being wrong, as it has been reported that there are some bugs with it. I found a thread on gearhead.efi , not for my particular ECM or XDF, but for an earlier year, but similar issue. Turns out it was the same problem, though. The BIT for Vats , location 8013 in my bin, is set at the factory at FF. Un-checking the VATS Select flag changed it to FE. However, the ECM is looking for zero / non zero, so no matter what was changed, the value was always going to be more than 0. I changed this bit to 00 using the hex editor in Tunerpro, burned a new chip, and it fired up on the first try!!!!
Man, did it sound good!!
Thanks to all for helping this old man keep progressing. Just need to finish up the interior, and we can be back on the road ( with a bigger smile!)
------------------ '87 GT in process, including GA / Seville brakes, Poly Suspension, '95 3800 Series 1 SC ( 225 hp ) 4t60e.
SUCCESS!!. I kept digging on the XDF file maybe being wrong, as it has been reported that there are some bugs with it. I found a thread on gearhead.efi , not for my particular ECM or XDF, but for an earlier year, but similar issue. Turns out it was the same problem, though. The BIT for Vats , location 8013 in my bin, is set at the factory at FF. Un-checking the VATS Select flag changed it to FE. However, the ECM is looking for zero / non zero, so no matter what was changed, the value was always going to be more than 0. I changed this bit to 00 using the hex editor in Tunerpro, burned a new chip, and it fired up on the first try!!!!
Man, did it sound good!!
Thanks to all for helping this old man keep progressing. Just need to finish up the interior, and we can be back on the road ( with a bigger smile!)
Glad you found the issue. And you are correct, for switch options, 00 = Off and any other setting could be interpreted as "ON" (ie: 01-FF).
Did switching the VATS option to "00" stop the VATS-related DTCs from setting as well?
