New Stand-alone ls6 troubleshooting help needed

**WTF Desert Racing** · 07-20-2009, 10:33 AM

Hey Gen III guys, the time has come to ask for help. I have been reading threads and advice as I built up my new LS motor. It is now in a class 7 desert race truck the ready to fire up.. (not) No fire to at the plugs. There is Power to the PCM that was flashed with all the usual deletes (VATS, Rear 02, Transmission settings, Etc.) and there is power to the coil banks but getting no spark. I assume it is time to invest in a scanner or a hand held tuner. (suggestions or good deals?)

My questions are:

How do I test the PCM? Are there pin-outs that I can test for voltage that should tell me if it is OK?
How do I test the Crank and Cam sensors?

Thanks for the help and ideas on how to get this baby to fire
ms

**c5z28** · 07-20-2009, 12:35 PM

A scanner is good for codes, since it's in the truck your don't have a ses(check engine light) light do you?

**WTF Desert Racing** · 07-20-2009, 12:57 PM

Hey C5 Z28, Its a super simple install. No check engine light. Stand-alone harness (GM paired down to the basic operations) with a separate box for relays to fuel pump and fans. Strictly race application, so you just connect the main power, ignition power and hit the start button.
I see you are in the Bay area, I assume that is the SF, San Jose area. Im in Santa Cruz. Do you know folks out here in the CA Bay area that woul would recommend to take a look at the PCM?

Thanks for your reply
ms

**c5z28** · 07-20-2009, 01:07 PM

Well there is nick at newtech he is a tuner in the hayward area, or you could mail the pcm off to frost his a sponsor on this sight. Thats weird power to the coil packs but no spark?

**WTF Desert Racing** · 07-20-2009, 02:03 PM

Thanks for the Synergy lead, Ill check em out. Re-weird.. I know, the only thing I can come up with is a dead crank or cam sensor. (Both are new) I guess I could have got a bad one... Somone has got to know how to test those sensors. Thanks again. ms

**c5z28** · 07-20-2009, 03:27 PM

Sorry my bad nick at newtech
http://www.newtechperformance.com/
rick is at synergy
I have never done it but if you have a chevy pickup an ls-s series you may try to swap coilpacks just to see if those aren't the cause.

**WTF Desert Racing** · 07-20-2009, 08:17 PM

I spoke to Rick at Synergy. Seems like a sharp guy that knows his way around a Gen III. He had a couple suggestions like checking the grounds on the PCM and coil packs.

Doubled them. no spark.
I may just take the PCM to Synergy and have them test it. I should pick up a spare set of coils for the race box but have not gotten to it.

The hauler truck is not LS based, (97 k3500 7.4 with a whipple) but a good idea. Thanks for the input. Ill be sure to post progress. Who knew sorting the little odds and ends on the LS upgrade would start with even getting it to spark.

**Frost** · 07-21-2009, 07:28 AM

It will start (albeit it roughly and with a backfire) with no cam sensor connected.

**farmtruc** · 07-23-2009, 01:50 PM

Be sure you're getting power to the coils?

Also, this is a sneeky one, when you're cranking over the engine, be sure there is ignition power to the pcm. Having ignition with key on is different while cranking, so test while cranking, not just key ON position.
Also, you can test this by taking power to your ignition ON wire, but if it starts, you'll have to disconnect this wire to shut the engine off, lol, but do this just for testing purposes,

good luck,
allen

**WTF Desert Racing** · 07-24-2009, 09:15 AM

Hey Allen,

Thanks for the ideas. Since this is in a race application, there is really no key. Just a master power connect that heats up a control box of relays for fuel pumps, fans and “key on” power to the pink PCM wires. So the start button is directly off the main power supply and should not be interrupting current to the PCM. With power on, I have 12 volts to the red wires at the coil pack connections. I assume, all the coils need to spark is a ground signal from the PCM. I have re-doubled the grounds to the coil packs and block at multiple points and plan to add a nice fat ground to the PCM just for good measure tonight.

The only other idea I have , since you guys say it should run even without a cam sensor (badly) is to replace the crank sensor, unless someone can tell me how to test it. Keep the ideas coming… Im drawing at straws at this point

By the way, I took my PCM to Synergy Motorsports and had them check out the tune that that I paid some Ebay-yahoo to lay down. It was supposed to be a custom setup with the usual race deletes. It turned out to be a stock tune for a 2004 Tahoe with only VATS removed… So lesson learned… Ebay tunes are a crap-shoot at best.

Thanks for the ideas and support

**WTF Desert Racing** · 07-26-2009, 07:58 AM

Still no spark...
ARGH....
I guess my next step is to go get a scan tool/ tuner that can do a "Crankshaft Position System Variation Learn function". That tool should be able to tell me if it reading RPM while cranking the engine over and be a test for the crank sensor. Grounds have been doubled and tested,PCM has been tested, coil packs have power.
What else am I missing?
Any reccomendations on a tuner that can do a crank re-learn under $400??

**99transamC/FIA** · 08-08-2009, 11:31 AM

do you have the obd2 connector so you can use the scanner? that connector is part of the dash harness on a stocker i belive. what wiring harness is in the truck?What motor?What year computer?
Not to be a ass,but is it the right sensor for the crank(24 or 52)and computer?
If you need someone to tune it Frost is the man around here.

**kaine806** · 08-09-2009, 05:57 AM

if your looking for a good scanner/data logger check out the ( dashdaq ) I've been running one for year's It's the best scanner/datalogger I have ever used..

**WTF Desert Racing** · 08-10-2009, 11:47 AM

Hey, thanks for the input. I have looked at it. It seems like a lot of interesting features is a pretty usable package. How do you like the GPS system the series II versions include?
Thanks again.

**WTF Desert Racing** · 08-11-2009, 09:42 AM

Originally Posted by 99transamC/FIA

do you have the obd2 connector so you can use the scanner? that connector is part of the dash harness on a stocker i belive. what wiring harness is in the truck?What motor?What year computer?
Not to be a ass,but is it the right sensor for the crank(24 or 52)and computer?
If you need someone to tune it Frost is the man around here.

Hey, I do have an ODB-II connector as part of the standaone box-o-relays to power the engine harness. I have not yet picked up a scanner. The harness is a 1999 camaro that has been paired down to remove any smog, transmission, cruise junk. Pins have been removed at the PCM connector as well. The computer was tested and flashed for a basic 1999 camaro with VATS removed, by Synergy Automitive (good shop here in the bay area) The engine internals are 99 camaro block and crank with a Comp Cam (LS1 style, not the LS2 fromt cam trigger) The reluctor ring is the older 2 piece. I was not aware that there is a difference in the sensors, but just to be sure, I picked up new crank and cam sensores for a 1999 camaro. I have not put them in yet. but will update once that is done.

As I see it, next steps are to install the new sensors and test for spark. If no spark,, I need to run a scan tool that reads real-time RPM, pull all the plugs to get a decent rotation speed and check to see if I am getting RMP readings... That should tell me if the crank to sensor relationship or damaged reloctor is an issue. Seems like I should be able to put a digital volt meter on the leads from the sensor to see if it is getting a rotation signal back to the PCM.

Any other thoughts or ideas?
Thanks for the help
ms

**c5z28** · 08-11-2009, 09:47 AM

you'll have to join tech to get an answer but jusy copy and paste your original questions-hopefully they can help. this is the section you want
http://www.ls1tech.com/forums/advanc...ring-tech-107/