can some one tell me why this firebird wont start**vid inside**
12-23-2007, 03:34 PM
#62
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i see, so i need to talk to the engine builder and ask him if they installed the same reluctor wheels on our motors. say they are different can the crank be taken out and the right reluctor wheel be installed on the crank?
12-23-2007, 03:43 PM
#63
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I'm with EDCMAT.
Although, I'm pretty sure this dude won't know anyone who knows how to operate an oscilloscope let alone own one without paying for their service.
What do engines need to run? Fuel, Air and spark.
Most of the engines out there require the function of the cam, crank and tps sensors together to send out fuel and spark. If there is one that is not working, the computer will cut off spark and fuel. Clearly you have fuel pressure, and clearly no spark. You fixed the sensor issue. Did you clear the code, disconnect and reconnect the battery to see if it came back during cranking? Also, try monitoring other sensors and stuff in the scanner. You may be able to pick up long and short term fuel trim (LTFT and STFT) Or spark operation of any sort.
So it seems lack of spark could be the culprit. I'd recheck that every wire and GROUND is securely connected in the ENTIRE ignition system. If you have a multimeter, this will make the job way easier. And if I were you I'd check other powertrain management relays.
Also, if your fuel injectors are firing and there is no spark, they will wash down your cylinder walls eliminating all capabilities of the piston rings to make a complete oil seal, thus rendering them compressionless. That could explain the odd rpm fluctuation while cranking. Hope this helps.
Although, I'm pretty sure this dude won't know anyone who knows how to operate an oscilloscope let alone own one without paying for their service.
What do engines need to run? Fuel, Air and spark.
Most of the engines out there require the function of the cam, crank and tps sensors together to send out fuel and spark. If there is one that is not working, the computer will cut off spark and fuel. Clearly you have fuel pressure, and clearly no spark. You fixed the sensor issue. Did you clear the code, disconnect and reconnect the battery to see if it came back during cranking? Also, try monitoring other sensors and stuff in the scanner. You may be able to pick up long and short term fuel trim (LTFT and STFT) Or spark operation of any sort.
So it seems lack of spark could be the culprit. I'd recheck that every wire and GROUND is securely connected in the ENTIRE ignition system. If you have a multimeter, this will make the job way easier. And if I were you I'd check other powertrain management relays.
Also, if your fuel injectors are firing and there is no spark, they will wash down your cylinder walls eliminating all capabilities of the piston rings to make a complete oil seal, thus rendering them compressionless. That could explain the odd rpm fluctuation while cranking. Hope this helps.
12-23-2007, 09:09 PM
#65
The reluctor wheel issue is theres 2 dif wheels. If you have the wrong one, it wont run, because it produces a crank signal thats different. Different number of pulses.
But, even if this was your problem, it would still try to start. It would pop, spit, sputter, etc, but it would attempt to start.
You need some diagnostic equipment. Mainly a scanner and a scope.
But, even if this was your problem, it would still try to start. It would pop, spit, sputter, etc, but it would attempt to start.
You need some diagnostic equipment. Mainly a scanner and a scope.
12-23-2007, 09:33 PM
#66
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The reluctor wheel issue is theres 2 dif wheels. If you have the wrong one, it wont run, because it produces a crank signal thats different. Different number of pulses.
But, even if this was your problem, it would still try to start. It would pop, spit, sputter, etc, but it would attempt to start.
You need some diagnostic equipment. Mainly a scanner and a scope.
But, even if this was your problem, it would still try to start. It would pop, spit, sputter, etc, but it would attempt to start.
You need some diagnostic equipment. Mainly a scanner and a scope.
all the motor does is turn over there is no start and the spark plugs look new still. the grounds are all tight.
12-27-2007, 06:11 PM
#69
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well as far as the reluctor wheel goes this is what the engine builder told me.
"I think he's having a no spark issue and may need to do a crank relearn. Both motors were the same and have the same 24x reluctor wheel on them. You may want to check the run out on the reluctor wheel on the one that won't start, if there is too much(more than .020) it won't start or run right either, it's a pretty rare problem that I have never personally seen but have heard of".
"I think he's having a no spark issue and may need to do a crank relearn. Both motors were the same and have the same 24x reluctor wheel on them. You may want to check the run out on the reluctor wheel on the one that won't start, if there is too much(more than .020) it won't start or run right either, it's a pretty rare problem that I have never personally seen but have heard of".
12-27-2007, 06:54 PM
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no I'm with EDCMAT.
Although, I'm pretty sure this dude won't know anyone who knows how to operate an oscilloscope let alone own one without paying for their service.
What do engines need to run? Fuel, Air and spark.
Most of the engines out there require the function of the cam, crank and tps sensors together to send out fuel and spark. If there is one that is not working, the computer will cut off spark and fuel. Clearly you have fuel pressure, and clearly no spark. You fixed the sensor issue. Did you clear the code, disconnect and reconnect the battery to see if it came back during cranking? Also, try monitoring other sensors and stuff in the scanner. You may be able to pick up long and short term fuel trim (LTFT and STFT) Or spark operation of any sort.
So it seems lack of spark could be the culprit. I'd recheck that every wire and GROUND is securely connected in the ENTIRE ignition system. If you have a multimeter, this will make the job way easier. And if I were you I'd check other powertrain management relays.
Also, if your fuel injectors are firing and there is no spark, they will wash down your cylinder walls eliminating all capabilities of the piston rings to make a complete oil seal, thus rendering them compressionless. That could explain the odd rpm fluctuation while cranking. Hope this helps.
Although, I'm pretty sure this dude won't know anyone who knows how to operate an oscilloscope let alone own one without paying for their service.
What do engines need to run? Fuel, Air and spark.
Most of the engines out there require the function of the cam, crank and tps sensors together to send out fuel and spark. If there is one that is not working, the computer will cut off spark and fuel. Clearly you have fuel pressure, and clearly no spark. You fixed the sensor issue. Did you clear the code, disconnect and reconnect the battery to see if it came back during cranking? Also, try monitoring other sensors and stuff in the scanner. You may be able to pick up long and short term fuel trim (LTFT and STFT) Or spark operation of any sort.
So it seems lack of spark could be the culprit. I'd recheck that every wire and GROUND is securely connected in the ENTIRE ignition system. If you have a multimeter, this will make the job way easier. And if I were you I'd check other powertrain management relays.
Also, if your fuel injectors are firing and there is no spark, they will wash down your cylinder walls eliminating all capabilities of the piston rings to make a complete oil seal, thus rendering them compressionless. That could explain the odd rpm fluctuation while cranking. Hope this helps.
12-27-2007, 07:02 PM
#73
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I just listend to it again 5 time's. I still say cam timming is off or valve's are hanging open for some reason. You should not get that pop out of the tb.
check the compression .
when he cracked the tb open you could really hear it popping out of the tb.
check the compression .
when he cracked the tb open you could really hear it popping out of the tb.
12-27-2007, 08:47 PM
#78
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I agree that either the cam was installed wrong or the wrong length pushrods were used or maybe the rockers are way over tightened which is keeping the valves from closing all the way. It definately sounds like it is losing compression through the intake .I would start by removing all the spark plugs and then remove all the rockers and do a compression check. If you get good compression on all cylinders I would then measure for the correct length pushrods to make sure the ones you have are actually the right ones. Then I would take my time and install the rockers using the correct procedure and hopefully your engine should start assuming you have fuel and spark ! FUEL + SPARK + Air + Compression = a engine that runs ! Good luck !!
12-27-2007, 09:21 PM
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The cam could be off, also it does sound like it is loosing compression through the intake. Its a really weird sound i would definitely just pull the timing cover and double check the dot to dot. Just because the engine builder says its ok doesnt make it so. He is just trying to cover his ***. So get a compression tester and test compression and also check cam timing.