Andrew MacPherson
2005 C6 Corvette (HP tuned cam/injectors/exhaust etc)
2003 Hummer H2 (HP tuned CAI only)
1995 TT Viper
2003 Escalade
Also, I hooked up my Snap-On Solus pro scan tool and watched cam and crank counts. The cam count wouldn't change until I reved the car to about 1500rpm.
Andrew MacPherson
2005 C6 Corvette (HP tuned cam/injectors/exhaust etc)
2003 Hummer H2 (HP tuned CAI only)
1995 TT Viper
2003 Escalade
The thing is, when it's cranking and not starting I can see the cam sensor counts incrementing. A while back I also measured the distance from the gear to the cover at different points of rotation thinking that the Summit gear was not to spec, and it checked out.
Thanks for the additional input/experience though.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
I finally got a chance to get under the car, forgot to connect the sensor :derp:
just got done filling the trans, fuk GM for making it so retarded to fill an A6 on a vette.
-Carl
OK, haven't messed with this in a while. I just scanned it when it's cranking without starting and I am getting an RPM signal so it's not the crank sensor. Soooooo?
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
I'd be looking at cam & crank on a labscope. Do you have any access to one? Cam, Crank correlation could be the issue. I've seen this problem with no codes too.
You mean like an o-scope? I suppose I could wrangle one up somewhere. What would I be looking for exactly?
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
You'd be looking for the pulse train coming or lack of from the sensors.
So since the motor is apart I was able to get a good look at the internals. The cam gear was intact and the reluctor looks straight as an arrow. Could it be that the reluctor is clocked wrong? Ignortant question perhaps, I'm not sure if it even matters the orientation of the reluctor in relation to the crank.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
Caaaaaaarrrrrlllllll!
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
Yes, it's a double roller from Summit. I do run an iron block so I guess I could take that out of the equation and run the rear cam sensor....or can I? I'd really like to not have this problem when the new motor goes in.
Last edited by 5_Liter_Eater; 04-04-2013 at 09:50 AM.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
The reason I asked is I have had similar problems on a couple of cars over the years and something we discoverd the other day made me think about situations like this.
The issue was with a transmission output speed sensor. We kept loosing a speed signal and after all attempts at wiring fixes, it was suggested that it maybe the speed sensor is TOO close. Seemed far fetched, but tried shimming it and damn if it didn't work. The best I could figure is that the sensor being that close is still reading the grooves and never really makes a transition from high to low.
It makes me wonder if the same could be true on the cam sensor. Especially when dealing with a double roller cam gear or one that may have a shallow groove cut. Both cars I've had with this issue were also intermitten but both had double roller LS2 style set-ups and one I know for sure didn't have the issue until after the cam and chain install.
Just something to think about.
Jaime
Good points. Something I may have neglected to mention is that when I first dropped the motor in it was throwing cam sensor codes which ended up being a frayed wire but before I found that I thought it was the cam gear so I took measurements of the cam sensor, cover and gear and filed the cam sensor boss (~.010" IIRC) to get it closer to the gear. The thing is the cam sensor count increments while the car is cranking and doesn't start which makes me think it's fine but it could be a combination of the sensor being too close and the orientation of the cam gear on initial start.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
Have you hooked up noid lights to the spark and injectors to see what they're doing when it doesn't start?
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Never investigated the injectors but I took a plug wire off and hooked up a plug and grounded it and it was throwing spark while cranking with no start.
And it smelled of gas when not starting so it definitely seemed like it was getting fuel. Soooo, no clue why gas + spark = no start.
Last edited by 5_Liter_Eater; 04-04-2013 at 01:15 PM.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
Just leve the cam sensor out and let the crank sensor take care of it.
Uh, then it will double start every time and fire in batch mode (if it hasn't been this whole time).
Last edited by 5_Liter_Eater; 04-04-2013 at 01:32 PM.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game