Finely got my truck fired up but there's a problem

[TieRod]

I've been working on a 8.1 using Raylar head's, cam, and intake. I decided to start it with out the trans sense it's not done yet. The first time I tried it the engine fired up ran 3 minutes then died after that it would run for only a minute. Then it would rev up and die. Once I made it to the driver seat and cracked the throttle a couple times. It would rev very quick and bounce off the rev limiter. But it would not idle now it won't even start. I used a double roller timing chain from Cloyes. The problem was that the stock cam sensor hit the timing chain. I had negative .051 clearance so I shimmed it out. I've tried shims from .060-.160 but no luck. I keep getting cam sensor input voltage high. I even tried anther sensor still got the same code.

[Haulin' 8.1]

Is that a P0343 to be specific?

 

Vernon

[Haulin' 8.1]

That engine should start and run without a Camshaft Sensor Signal, I think there's another problem you're not aware of yet. There's a lot of tranny protection in the programming, perhaps the PCM's not happy with the fact that it's not getting any transmission signals? Also in this situation it could also be valve lash too tight. Once the lifters pump up they hold the valves off the seats just enough to prevent running. There would be very little back fire on a fuelie intake like that one, but listen for it at the throttle body with someone cranking the engine over.

Try backing off the lash a hair and see if it runs.

 

In any case "Stuck on high" is basically a no change signal code, maybe it's just too far away now? I'm not familiar with the layout but you're shimming it out to clear the timing chain, does that equate to further away from the reluctor wheel? If so that's your problem.

 

For the Code you're getting it could also be that your camshaft's reluctor wheel is damaged or is missing. If it took a wack and bent just a little bit it will cause a no read.

 

Hope this helps, if not give some updated information and I'll tell you what I can think of.

 

Vernon

[Haulin' 8.1]

I just thought of something else, without a torque convertor full of fluid attached to the flexplate you really don't have much "flywheel" inertia. So perhaps the engine will start and run in open loop with a high idle speed but once it warms up and tries going into closed loop it can't maintain a low idle without a flywheel mass to keep the crankshaft rotating smootly between firing strokes. Especially with a big lumpy cam like yours, as you know things that make an engine build torque at high engine speeds usually reduce torque at lower engine speeds.

 

Vernon

[TieRod]

Thanks for the help. I think I need to get the trans in it. Thats probably whats wrong. I have the lash set to the loose side. The rocker arm are making allot of noise. The timing chain is the reluctor wheel for the cam censor. I had the sensor .010 from the chain with no luck. I'll check to see what the code number is. This help me allot. The tools that I need to rebuild a Allison are on national back order. If it wasn't for that my trans would be done.

[vhato]

I cannot speak about the Vortec 8100. However I assisted on 4 Cam swaps on an '02 LS1 in a Camaro. These were major changes from stock and the engine would not idle at all for more than 2-3 seconds before dying. Once we editted the Volumetric Efficiency Table all was well. But we had to go into the PCM to do it and at the time LS1Edit was the tool. We all use HPTuners now. The PCM's stock coding didn't understand the changes the new cam made during idle.

 

I dunno if that is your problem, but I ran into that 4 times on an LS1 5.7 V-8.

[TieRod]

I going to wait untill i get the trans back in it. I need to fix the evap, and the vent the crank case. Hopefully next weekend I'll have some pix of thing you'll have to do to use Raylar intake.

Later,

Chris

[TieRod]

Heres what I found out so far. On the 04' GM changed the timing chain sproket, cover, and sensor. Cloyes double chain is for a 04'. Raylar was fighting this last week and found this out. They gave me the GM part number for a new sproket and sensor to fix the problem. I should have them by friday and I will keep you post, if it works.

Later,

Chris