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help me out...car not starting...

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Old Apr 26, 2007 | 12:50 PM
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Default help me out...car not starting...

Swapped shortblocks out of a buddies car. Swapped cam and heads along with it. Lined cam dots up just fine etc...anyways motor is back in car, has fuel, cranks over and rockers springs all move up and down just fine, seems like something is telling it not to start up...any ideas?
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Old Apr 26, 2007 | 01:40 PM
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-there are 2 grounds on the back of the driver side head, those are both connected,

-I took a fan relay out and swapped it with the ignition relay, still does the same...

-Its definately getting fuel to the rail

-I plugged in a predator to the obdII port so im pretty sure the ECM is fine.

-It just cranks, like i said, springs rockers all move just fine as you are cranking it, so timing chain isnt busted already..

any takers?
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Old Apr 26, 2007 | 01:49 PM
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car is a 98 with a4 harness even though its a 6speed now...
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Old Apr 26, 2007 | 02:06 PM
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Crank position sensor, or cam position sensor. We did a motor swap on a buddies car and had the same results. Ended up being the crank position sensor. It tells the pcm where the crank is in relation to the cam and which coils to fire at which time. He replaced it without me there so I'm not really sure where its at...(btw its easy to break when dropping the motor back on from what I understand...
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Old Apr 26, 2007 | 03:09 PM
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^^^^ just put another crank sensor from a working car, still the same thing...

correct me if im wrong, if the cam sensor is bad, the car would still run? the car isnt even trying to fire...

Last edited by TRU-2GM; Apr 26, 2007 at 03:16 PM.
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Old Apr 26, 2007 | 03:39 PM
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Fuel or igntion man. Check your coil harnesses and the voltage output of each individual coil. Check all fuses under hood and dash. Also, get a fuel gauge on the shrader valve under the hood off of the fuel rail and be sure you have atleast 50psi fuel pressure when the key is turned forward.
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Old Apr 26, 2007 | 04:09 PM
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There should be three grounds on the ds head, two on one bolt and one on the other.
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Old Apr 26, 2007 | 04:42 PM
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Originally Posted by chuckyt1
There should be three grounds on the ds head, two on one bolt and one on the other.
I have read that, but im almost positive that there are only two coming out of that harness, and they are on the drivers side head.

--and there is another ground on the block by the starter going to the battery i think

--and one grounded to the driver side block (small one) and it goes to the frame rail in front of the wheel

--is there anything grounded to the alternator? there is a skinny bolt on the back side of it that isnt doing anything...
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Old Apr 26, 2007 | 08:53 PM
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nevermind, there are definately 3 ground wires on the back of the head. And they are all grounded to the same place on the back of the head...

--coil packs have 12.5 volts to them when the key is turned to on, once cranking they are around 10.5 or so...
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Old Apr 26, 2007 | 09:34 PM
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Which push rods did you use? If it's getting fuel, and spark, maybe the valves aren't closing...
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Old Apr 27, 2007 | 01:59 AM
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did a leakdown test....100% leakdown, NO compression on any of the cylinders. Well 3,5,7 anyway. supposedly this shortblock was swapped out by GM due to piston slap...when really it looks like they may have started to re-ring it and maybe just put them back in without the lower rings before swapping to another crate...sucky deal....
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Old Apr 27, 2007 | 02:04 AM
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*****!

Who's car is this anyways?
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Old Apr 27, 2007 | 03:19 PM
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its nates, with the 98 white TA
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