john morse

Engine 2013 6.2 Vortec w/ VVT deleted - aftermarket cam and 4X single roller set.. . ECM 2008 # 12612384 Harness PSI 1039 standalone. PROBLEM = NO codes, No Spark (W/ tester) No injector pulse (W/noid lite) Bat 12V @ J1 - pin 20 and w/ brake on @ pin 9. Key on 12V @ J1 - pins 19 and 47.and at MAF, injectors and coils. Live data shows MAP and MAF right on and cranking RPM is 170. Initial APP code was cleared w/ APP wire swap at D and F. ECM chip and tune by Tempe Speed
Grounds are proper and plentiful. Tempe Speed - because of my complaint - put the ecm into a vortec truck and it started immediately. This would indicate harness problem so I ohmed out every single wire from pin out to device and all was 100%. How can I show live data RPM but have no spark pulse, no injector pulse and NO CODES?
Injectors are brand new. Coils are original G M. . .

Project GatTagO

iTrader: (7)

What sort of vehicle? Not that this matters much...
Andrew

john morse

78 El Camino.....My first swap was a 350 TPI that I put into my 55' Nomad.No issues on that one with same tuner - Tempe Speed in Arizona.

This one was one of those "help a friend with the wiring" jobs cause I am just handy like that. My first, of course, was drive by cable vs drive by wire and it only required 1 02 sensor and had a distributor and coil. This LSX stuff is a bit different. Especially with the DBW which does, by the way, responds to APP at the TB. I actually thought that a freshly chipped and tuned E 38 and a stand alone harness would not be such a problem. My plan now is to check for grounded coil packs I guess possibly overloading the ECM????? Nearly everything is new! Running TH 400 and a Dakota digital speed sensor 8000 ppm w/ a Dakota Digital interface module to provide a 4000 ppm signal to the ECM. No provisions for NSS on my harness.

Project GatTagO

iTrader: (7)

In this type of situation, I would take a step back and start from the beginning, making sure everything is correct. Take nothing for granted.

Andrew

john morse

Great point. Though I have verified all hots are in the right places and sensor wires having continuity from pins at X1/X2 ECM connectors to associated devices, I have NOT verified knock sensors 02 sensors, coil packs or injectors for grounded or pin #'s are correct to these devices from ECM connectors.. As you stated...just cause they are new does not mean that they are not defective. I am beginning to understand the the ECM can "check out" the negative pulses to injectors and or coil packs much the same as a circuit breaker would if there is too much load,,, ie defective/shorted devices or pinned wrong, etc. Next time through the harness wiring I am going to be checking for grounded wires and devices in addition to continuity testing of wires and devices that I did not verify the first time. Thanks for the reply. I just have more testing to do is all.Somewhere else to go!!!!

jmd

iTrader: (4)

Have you worked through any diagnostics of a factory manual? The PCM worked in that Vortec truck.
Maybe the diagrams and diagnostic steps for that model vehicle would help lead you to some checks that would narrow down what's up.

brandon6.0

iTrader: (32)

Post a pic of engine front timing cover it will help.

Without the vvt crap u need a ls2 front cover. With vvt deleted, and using a oe vvt cover u will NOT get a cam signal. I ran into a issue like this once.

Also make sure the cam pigtail plugged directly into the cam sensor. Bypass the original vvt small harness tht bolted to the front cover.

john morse

I DID use the vvt timing cover and just removed the 5 wire harness and plugged the psi standalone harness cam sensor connector into the original cam sensor. I am grateful for your answer. This never occurred to me but I do see that the VVT delete kits do offer cover as well. Why, I do not know or understand but do believe!
1 what is the difference in covers? Distance to sensor?
2 you had no injector pulse - did you also have no spark as you recall?

Project GatTagO

iTrader: (7)

With regard to the cam sensor pigtail. Before removing it, confirm with PSI how the cam connector is wired. The pigtail harness swaps the A and C pins. So if the harness was built for the pigtail, then it needs to go through the pigtail or have pins A and C swapped at the connector. Etc...proceed accordingly.

Andrew

brandon6.0

iTrader: (32)

Im nit real sure what the diff is but it does need a non vvt cover. Engine want run bc its not getting cam senser signal. Ran into this issue withmy first vvt delete setup. Swapped covers car fired right up!!!

-TheBandit-

iTrader: (1)

The sensor position on a VVT cover is further away from the block to accommodate the VVT phaser. When installing a non-VVT cam, you need the non-VVT cover to position the sensor closer to the cam sprocket so it can sense the timing reliefs properly. Without this information, the ECM won't know what stroke any of the cylinders are on so I don't think it will run the injectors or spark.

-TheBandit-

iTrader: (1)

Here's a good photograph showing the difference between the two timing covers. VVT is on the left, non-VVT on the right:



You can see the cam sensor (yellowish color) is further out on the VVT cover.

john morse

So I got the correct cover on the way for the car owner.. Further research shows me that the intended gap between sensor and reluctor is .030. I see that the VVT cover wouldn't even have come close to that! The ECM has been "blind" to the cam sensor!! That explains to me how the crank sensor showed RPM yet no spark or injector pulse. I am 1000% certain that this was a mistake during the original build. You guys have taught me a great deal,. The original rockers and push rods were used as well with the aftermarket cam..Perhaps I have more than one issue.Many thanks to those of you that have opened my eyes to a BIG mistake. I really should have known better but did not select the parts nor did I understand the difference in VVT and non-VVT timing covers. I do now.
I am in Florida right now until Aug 13 for medical reasons and can't wait to get back to this project in Missouri. I believe I have seen the light and expect to see spark and injector pulse after a few issues are worked through. How embarrassing! Many, many thanks to all of you. Why the ecm did not produce a code is a mystery. It would have been a nice clue to the problem.

brandon6.0

iTrader: (32)

Report back if the cover fix it. Weve had a dicussion were guys have said a ls will start without a cam sensor signal. I know from experience it want. Your experience will be a perfect opertunity to test tht theiry lol

Project GatTagO

iTrader: (7)

I am glad to see a promising resolution to this!

Don't forget to double check the pin-outs of the cam connector and cam sensor!

Andrew

john morse

Yes, of course I will re-post regarding non VVT cover solving my problem. But you already know the answer to that story. I know you do. What really surprises me is that there was no code regarding cam sensor. Don't those engineers at G M know how silly a guy can be in pursuit of horsepower? I propose "DTC Codes for Dummies". After all, there are certainly dumb codes that many mechanics know actually mean little. I worked on an 06 Colorado 5 banger 3 weeks ago that told me the left rear tail lite was out and that the window motor had a problem!! Regarding the no code related to blind cam sensor - I will get to the bottom of it though. I am no quitter - persistent to stupidity! You know as well as I do that the cam sensor was blind and will be if air gap exceeds .030. i also know that in some cases, when a sensor fails, the ECM remembers the last good data and tries to overcome the problem - TEMPORARILY.

I am certainly no LS expert but my mistakes are slowly making me a lot more knowledgeable about these motors. The motors will teach us. Even the clueless guys like me!

Project GatTagO

iTrader: (7)

I don't know how fault codes get triggered exactly, but I suspect since the sensor was working fine, that was good enough for the ECU. It clearly didn't understand that there was no actual cam signal being sent to the ECU. The internal sensor diagnostics probably just look at the voltage reference to the sensor and as long as those appear good (good sensor in your case) not code is generated.

Andrew

-TheBandit-

iTrader: (1)

Noone can be expected to know everything. That's why we're here - to help one another. I have and continue to ask a lot of questions. How else can we learn?

You're on the right track. Good luck when you get back to it.

john morse

Got back to the project August 15th. Swapped timing cover and cranked engine over looking for injector pulse (with noid light) and spark (with a standard spark tester). Had both.
Ready for initial start up now today Thanks to all of you.

Jimbo1367

Don't tell me wifey that or you'll be starting a unwinnable argument. Ask me how I know. LOL