hbhc

iTrader: (8)

I have a new build that turns over, but will not start. Computer is a 411 with a Frost SD tune. I was getting error P0107 that I was able to resolve, the only other error I'm seeing is the P1637. Would this error prevent the car from starting or do I have another issue? I have checked my PCM grounds, power, etc. and I haven't found any other problems.

Thanks, Scott

flame

iTrader: (13)

It is a charging system fault so no it should not keep the engine from starting. I attatched the testing procedure.

bigboykilroy

iTrader: (48)

Have you tested for fuel and spark?
I wonder if the VATS is still enabled..
are you able to test that pcm on a friends fbody?

hbhc

iTrader: (8)

Thanks for the replies, flame & bigboykilroy.


VATS are definitely disabled.

When cranking, I do see RPM on my obd scanner, so I assume the crank sensor is good.

I have fuel pressure and compression.

I have verified the power and grounds to the PCM.

I have 12 volts at the coil harness pinks and on one side of each injector plug.

I tried a noid test light on the injectors and they do not pulse. I get a small single flash when I turn off the key.

I DON'T have spark or fuel.

The motor is an LS1, with an LS2 front cover. I have tried switching the two outside wires as noted in other threads.

The long block ran previously, but I now have a new harness, computer & injectors. The computer and tune were done by "Frost", so I think I'm good there.

I believe my grounds are good, but I will re-verify. I haven't changed out the cam sensor yet as it ran before, but I'm not sure what else to try...

Any other ideas?

Thanks, Scott

flame

iTrader: (13)

Do you have power to the injectors and coils while cranking?

hbhc

iTrader: (8)

I sure thought I had checked that, but there was no power during cranking! I put key in the "on" position and tried starting with a bump switch. It fired up instantly!!!! Looks like I missed the obvious, thanks for pointing me in the right direction Flame!

Scott

flame

iTrader: (13)

Seen this way too many times. Glad you got it figured out!

Duffster

iTrader: (103)

HBHC,

Raising this thread....

Although you thought you had power, what did you do to ensure you had power???

hbhc

iTrader: (8)

Duffster,

To test, I left the ignition switch in the "run" position and then manually jumpered power to the starter solenoid and the car fired right up. I then realized that the coils had power in the "run" position, but not while cranking. I had accidentally wired to a switched power source that wasn't hot during cranking. Hope this helps and good luck!

Duffster

iTrader: (103)

I'm a little slow on this...

I can crank the car all day. Turns just fine (charged battery before trying).
I have about 8.5-9.0V at the alternator hot-wire. Car doesn't appear to be fueling or firing but I've got the same code about the alternator for some reason.

Was yours cranking before this jumper test?

Thank you,

D

hbhc

iTrader: (8)

Duffster,

My car would crank over fine, but obviously wouldn't fire up without power going to the coils during cranking. In my case, the P1637 error had nothing to do with the car not starting and I would guess that you have another issue somewhere. I remember how frustrated I was and I would love to be more help in solving this, but I'm pretty new to the LS1 platform and I'm afraid I don't have much to add.

Did you try leaving the car in the run position and manually jumping power to the starter solenoid?

Has the car ever run?

Are you sure the computer, tune and harness are good (no VAT issues, etc.)? I paid someone to convert my harness to stand alone and they had 3 wires that were not pinned correctly.

Should you have full battery voltage at the alternator wire? I think I remember reading that the LS1 needs to be very close to full voltage to start.


You need to confirm whether or not you have power going to the coils during run and cranking.

Good luck!

Duffster

iTrader: (103)

I've driven the car for the past 5 years without any issues. Last week I had the car die on me while driving but it restarted. Fuel pressure is fine. I don't know if the injectors are getting signal. The starter turns strong (I charged the battery before hand to make sure it wasn't voltage). I haven't tried jumping the starter since it turns fine I didn't suspect it. VATS shouldn't be an issue since it's the original key and again, the engine cranks just fine. Doesn't VATS stop the starter relay from picking up?

Thanks,

D

2TR

Hummm?

VATS:

Tamper: This mode happens when the vehicle is cranked, and the resistance value as seen by the module is not the same as the value stored in the module. When this happens, the module shuts down for 4 minutes. Even if the correct resistance is then seen, the car will not start for the 4 minute "time-out". The security light will also illuminate for the 4 minutes. The Start Enable Relay will not energize and the Fuel Enable signal will not be sent. HINT: if the key pellet is dirty, it will put the module in the "Tamper" mode. If your car fails to crank/start and the security light comes on, try cleaning the pellet, wait 4 minutes, and try again.

2TR

The VATS relink procedure for Gen III engines takes 10 minutes - no less:
1. Try to start vehicle - it may start and stall or not crank at all
2. Very Important: *Leave key in on position*
If you turn the key off you have to start all over again
3. Click on Relink VATS on the Flash menu
4. Wait 10 minutes
*Security* light on dash will go off after 10 minutes
5. Pull key from ignition
6. Wait 10 seconds
7. Start vehicle
If the vehicle doesn't start, repeat the entire procedure as a step may have been skipped.

Duffster

iTrader: (103)

i've never had any indication it was VATS.... no security lights or blinking or anything odd, but I'll try it in the morning... simple enough and free...

hbhc

iTrader: (8)

What ended up being the problem?

Duffster

iTrader: (103)

still don't know. The coils HAVE power when the ignition is turned on... I don't have a o-scope so I can't tell if they are getting signal to fire. Had someone else on another thread give me the voltage to the coils when keyed on... So I know that is good. Still trying to isolate issue.

D

hbhc

iTrader: (8)

Sorry to hear it's still not running. I wondered what the problem was and hoped you would have gotten it fixed by now. Please post a resolution when you do get it running.

You mentioned that the coils have power when the ignition is on, have you confirmed power when it's turning over? I had power while the key was in the "on" position, but I DID NOT have power while cranking (due to a wiring error on my part). When I left the key in the "on" position and manually jump started it at the starter, the car fired right up. Wish I had more to add, but good luck!