Car won't start after new main bearings
10-27-2010, 11:17 PM
#23
OMG, listen to Randy, he is right. What triggers the PCM to fire is when the cam reluctor triggers the cam position sensor. So, for every two rotations of the crank, the cam turns and triggers the firing. Basically what happens is this:
Start Dot to Dot (crank and cam dot at 12 o'clock) - Piston will be at TDC - PCM triggers spark
Dot on cam gear moves to the 6 o'clock, mean while crank dot moves 360* back to 12 (piston moves down then up removing exhaust and beginning intake stroke)
Then Dot on cam gear moves back to the 12 o'clock, mean while crank dot moves 360* back to 12 (piston moves down pulling in fresh air/fuel, then back up for compression stroke) - Cam completes one full revolution - PCM Triggers spark.
Now you might argue, "Ok, what if then you started 12 and 6 o'clock, the valves would not be in alignment, how would the PCM know that it was on the exhaust stroke and not the intake?" - I'll tell ya... The crank reluctor wheel. The crank sensor monitors when the crank has made TWO full rotations, since the crank is keyed to the crank gear, and as long as the cam is dot to dot (be it 12/6 or 12/12), when the cam triggers the cam sensor simultaneous to two rotations of the crank, Piston #1 should be on the TDC of the compression stroke and then SPARK.
The only way it will fire out of sequence is if you have the CAM POSITION SENSOR wires crossed, or you somehow crossed bank 1 and bank 2 for the coil plugs. This is not the case supposedly.
Now, onto real troubleshooting....
http://www.ls1howto.com/howto/fbody/...20dottodot.jpg
This is what you should be seeing, DOT to DOT. There will be a dot on that crank gear. If its not dot to dot, then the cam degree is WAY off. What you're describing sounds like a CLASSIC miss degreed cam. Additionally, if its degree is off enough, you could have also bent some or all of your valves. We're talking within a tooth or two can make or break the motor or cause it to not fire/build compression.
Tear off that front cover and rotate the engine until you FIND the crank gear dot and make sure it is correct to the tooth.
Start Dot to Dot (crank and cam dot at 12 o'clock) - Piston will be at TDC - PCM triggers spark
Dot on cam gear moves to the 6 o'clock, mean while crank dot moves 360* back to 12 (piston moves down then up removing exhaust and beginning intake stroke)
Then Dot on cam gear moves back to the 12 o'clock, mean while crank dot moves 360* back to 12 (piston moves down pulling in fresh air/fuel, then back up for compression stroke) - Cam completes one full revolution - PCM Triggers spark.
Now you might argue, "Ok, what if then you started 12 and 6 o'clock, the valves would not be in alignment, how would the PCM know that it was on the exhaust stroke and not the intake?" - I'll tell ya... The crank reluctor wheel. The crank sensor monitors when the crank has made TWO full rotations, since the crank is keyed to the crank gear, and as long as the cam is dot to dot (be it 12/6 or 12/12), when the cam triggers the cam sensor simultaneous to two rotations of the crank, Piston #1 should be on the TDC of the compression stroke and then SPARK.
The only way it will fire out of sequence is if you have the CAM POSITION SENSOR wires crossed, or you somehow crossed bank 1 and bank 2 for the coil plugs. This is not the case supposedly.
Now, onto real troubleshooting....
http://www.ls1howto.com/howto/fbody/...20dottodot.jpg
This is what you should be seeing, DOT to DOT. There will be a dot on that crank gear. If its not dot to dot, then the cam degree is WAY off. What you're describing sounds like a CLASSIC miss degreed cam. Additionally, if its degree is off enough, you could have also bent some or all of your valves. We're talking within a tooth or two can make or break the motor or cause it to not fire/build compression.
Tear off that front cover and rotate the engine until you FIND the crank gear dot and make sure it is correct to the tooth.
10-28-2010, 04:42 AM
#24
OMG, listen to Randy, he is right. What triggers the PCM to fire is when the cam reluctor triggers the cam position sensor. So, for every two rotations of the crank, the cam turns and triggers the firing. Basically what happens is this:
Start Dot to Dot (crank and cam dot at 12 o'clock) - Piston will be at TDC - PCM triggers spark
Dot on cam gear moves to the 6 o'clock, mean while crank dot moves 360* back to 12 (piston moves down then up removing exhaust and beginning intake stroke)
Then Dot on cam gear moves back to the 12 o'clock, mean while crank dot moves 360* back to 12 (piston moves down pulling in fresh air/fuel, then back up for compression stroke) - Cam completes one full revolution - PCM Triggers spark.
Now you might argue, "Ok, what if then you started 12 and 6 o'clock, the valves would not be in alignment, how would the PCM know that it was on the exhaust stroke and not the intake?" - I'll tell ya... The crank reluctor wheel. The crank sensor monitors when the crank has made TWO full rotations, since the crank is keyed to the crank gear, and as long as the cam is dot to dot (be it 12/6 or 12/12), when the cam triggers the cam sensor simultaneous to two rotations of the crank, Piston #1 should be on the TDC of the compression stroke and then SPARK.
The only way it will fire out of sequence is if you have the CAM POSITION SENSOR wires crossed, or you somehow crossed bank 1 and bank 2 for the coil plugs. This is not the case supposedly.
Now, onto real troubleshooting....
http://www.ls1howto.com/howto/fbody/...20dottodot.jpg
This is what you should be seeing, DOT to DOT. There will be a dot on that crank gear. If its not dot to dot, then the cam degree is WAY off. What you're describing sounds like a CLASSIC miss degreed cam. Additionally, if its degree is off enough, you could have also bent some or all of your valves. We're talking within a tooth or two can make or break the motor or cause it to not fire/build compression.
Tear off that front cover and rotate the engine until you FIND the crank gear dot and make sure it is correct to the tooth.
Start Dot to Dot (crank and cam dot at 12 o'clock) - Piston will be at TDC - PCM triggers spark
Dot on cam gear moves to the 6 o'clock, mean while crank dot moves 360* back to 12 (piston moves down then up removing exhaust and beginning intake stroke)
Then Dot on cam gear moves back to the 12 o'clock, mean while crank dot moves 360* back to 12 (piston moves down pulling in fresh air/fuel, then back up for compression stroke) - Cam completes one full revolution - PCM Triggers spark.
Now you might argue, "Ok, what if then you started 12 and 6 o'clock, the valves would not be in alignment, how would the PCM know that it was on the exhaust stroke and not the intake?" - I'll tell ya... The crank reluctor wheel. The crank sensor monitors when the crank has made TWO full rotations, since the crank is keyed to the crank gear, and as long as the cam is dot to dot (be it 12/6 or 12/12), when the cam triggers the cam sensor simultaneous to two rotations of the crank, Piston #1 should be on the TDC of the compression stroke and then SPARK.
The only way it will fire out of sequence is if you have the CAM POSITION SENSOR wires crossed, or you somehow crossed bank 1 and bank 2 for the coil plugs. This is not the case supposedly.
Now, onto real troubleshooting....
http://www.ls1howto.com/howto/fbody/...20dottodot.jpg
This is what you should be seeing, DOT to DOT. There will be a dot on that crank gear. If its not dot to dot, then the cam degree is WAY off. What you're describing sounds like a CLASSIC miss degreed cam. Additionally, if its degree is off enough, you could have also bent some or all of your valves. We're talking within a tooth or two can make or break the motor or cause it to not fire/build compression.
Tear off that front cover and rotate the engine until you FIND the crank gear dot and make sure it is correct to the tooth.
10-28-2010, 11:44 AM
#25
TECH Senior Member
See what Haans said.
10-28-2010, 01:42 PM
#26
Pull the number one spark plug and get the piston to TDC. That will put you were you need to be, Then look at the crank gear and see were the dots (arrow) at. Just checking ,did you put the timing gear with the chanfer toward the crank ? Remove the oil pump drive gear and see if the dot is behind it, some times the timing dot is low on the gear and the oil pump drive gear will hide it. And also look at the crank key and see if it pointing toward the #1 cylinder ,the key way is inline with the #1 rod journal it should be pointing at the #1 cylinder at TDC.
Last edited by Randy WS6; 10-28-2010 at 02:05 PM.
11-14-2010, 04:25 PM
#28
On The Tree
Thread Starter
Join Date: Jan 2008
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
Ok, found out that crank was in the wrong position, the arrow was not the same as the dot that is typically found on the crank. Got the car to start, but had a serious oil leak, long story short pulled the tranny and changed the rear main seal and reassembled. Now the car won't turn over, did some electrical testing and there is 12v getting to the starter but no power to the solenoid to activate the starter. Any ideas as to why my starter isn't getting power when I turn the key?
Thanks in advance
Justin
Thanks in advance
Justin
11-15-2010, 12:54 AM
#30
On The Tree
Thread Starter
Join Date: Jan 2008
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
The car is a six speed, I did hook the harness back up that goes to the tranny. When we put the bell housing back on we did pinch a wire between the housing and the block. I noticed the bell housing wasn't sitting right, so we pulled the bell housing back off, and saw there was a wire pinched that was two wires. I separated these two wires and taped them individually, since the one had the rubber coating peeled off from being pinched. I checked all my fuses and nothin was blown. Not sure where to look next
Thanks in advance
Justin
Thanks in advance
Justin
11-15-2010, 09:17 AM
#31
Maybe a vats problem or ignition switch. Could the wires that got pinched possibly have broken. I would untape those 2 wires and inspect them carefully to be sure the wire inside the covering isn't broke.
11-17-2010, 11:16 AM
#32
On The Tree
Thread Starter
Join Date: Jan 2008
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
The wire that was pinched, I seperated the two wires and taped them individually. So Im pretty sure they weren't broken. I checked all my fuses to see if anything was blown and nothing was. The starter worked fine, then I pulled the tranny and replaced the rear main cover and reinstalled the tranny, now it won't turn over. This is extreremly frustrating for me, considering I put tons of time into working on this car in the last two months, and now for it to be all back together, and something that was working just fine, isn't now, has me at going crazy. Does anyone know what the starter checks for before it turns over. Meaning, there's gotta be stuff it checks before it sends power to the starter, I can check these things to try and trace the problem.
thanks in advance
Justin
thanks in advance
Justin
11-17-2010, 01:19 PM
#33
Here's a few thing that might cause this, Check the neutral safety switch on the clutch pedal under the dash, It might be unplugged , or check and see if your getting a security light on the dash when you turn the key to start position, that could be the (passive key II), the wires that goes into the key switch might be broke .This is different from the VATS (Vehicle Anti Theft System) witch is the security system that sets the alarm off. Just throwing you some ideas out there to look at.
Last edited by Randy WS6; 11-17-2010 at 01:29 PM.
11-24-2010, 01:25 AM
#34
On The Tree
Thread Starter
Join Date: Jan 2008
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
Update time..
I was not able to determine why the starter wasn't working, so to get the engine to turn over I ran a wire from the starter to the battery just to get it to turn over so I could move on to bigger problems. So, the car starts up and there is a loud exhaust leak coming from the drivers side. I replace the exhaust manifold gasket, and the leak is still there. I can't determine where this leak is coming from, but it doesn't appear to be coming from the exhaust. almost sounds like it's coming from the intake manifold. I get a check engine light when I leave it idle, that says random cylinder misfire. I believe that I might have bent a valve or two, because when the engine was turned over originally, the cam and crank were not lined up correctly. Long story short there wasn't a dot on the crank gear, but there was an arrow, so I lined that up with the dot on the cam gear. If the cam and crank were off by a tooth, would that by the source of the random misfire code?
This car has become a HUGE pain. If I could do it again, I woulda pulled the engine and given it to a shop to fix, then I woulda reinstalled it. I am very overwhelmed at this point, any help is greatly appreciated.
Justin
I was not able to determine why the starter wasn't working, so to get the engine to turn over I ran a wire from the starter to the battery just to get it to turn over so I could move on to bigger problems. So, the car starts up and there is a loud exhaust leak coming from the drivers side. I replace the exhaust manifold gasket, and the leak is still there. I can't determine where this leak is coming from, but it doesn't appear to be coming from the exhaust. almost sounds like it's coming from the intake manifold. I get a check engine light when I leave it idle, that says random cylinder misfire. I believe that I might have bent a valve or two, because when the engine was turned over originally, the cam and crank were not lined up correctly. Long story short there wasn't a dot on the crank gear, but there was an arrow, so I lined that up with the dot on the cam gear. If the cam and crank were off by a tooth, would that by the source of the random misfire code?
This car has become a HUGE pain. If I could do it again, I woulda pulled the engine and given it to a shop to fix, then I woulda reinstalled it. I am very overwhelmed at this point, any help is greatly appreciated.
Justin
11-24-2010, 02:32 AM
#35
TECH Senior Member
iTrader: (96)
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,241
Likes: 0
Received 81 Likes
on
72 Posts
No need to panic dood......do a compression check to verify if your suspicions of bent valves are true. It shouldn't take long to hunt down this issue.
