*need urgent help* engine doesn´t run after head/cam install
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
*need urgent help* engine doesn´t run after head/cam install
My mechanic just finished the head/cam,LS6 intake,#30Injectors,underdrive pully install.
He also installed an other PCM and did the PCM swap procedure.
When he cranked up the engine it didn´t run.
He checked and found out:
when #1 Cylinder is on compresson then the spark plug from cylinder #6 fires
and when Cylinder #6 is on compression then sparkplug form #1 fires
So the engine will never run, I think :nonod:
I first thought the Camshaft position sensor may be it, but I don´t think it can be hurt during the cam install and also the service manual says the engine would run without that sensor?!?
Now I´m frustrated big time!!!
We pulled the timing chain housing to rechek the position of the gears, but they are correct. The lower gear has the sign on top and the upper gear
has it on the downside. So that´s #1 firing position, but that damn engine still fires at Cyl. #6 when Cyl. #1 is on compression?????
NEED HELP!!!!!!!!!!!!!!!!!
Michael
[Modified by Austrian Vette, 7:12 PM 3/9/2002]
He also installed an other PCM and did the PCM swap procedure.
When he cranked up the engine it didn´t run.
He checked and found out:
when #1 Cylinder is on compresson then the spark plug from cylinder #6 fires
and when Cylinder #6 is on compression then sparkplug form #1 fires
So the engine will never run, I think :nonod:
I first thought the Camshaft position sensor may be it, but I don´t think it can be hurt during the cam install and also the service manual says the engine would run without that sensor?!?
Now I´m frustrated big time!!!
We pulled the timing chain housing to rechek the position of the gears, but they are correct. The lower gear has the sign on top and the upper gear
has it on the downside. So that´s #1 firing position, but that damn engine still fires at Cyl. #6 when Cyl. #1 is on compression?????
NEED HELP!!!!!!!!!!!!!!!!!
Michael
[Modified by Austrian Vette, 7:12 PM 3/9/2002]
Racer
Joined: Aug 1999
Posts: 324
Likes: 0
From: 26 NM out the 304 radial of the ORD VOR Illinois
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
I am not sure about the LS1, but many newly designed engines use the cam shaft sensor to let the computer know where the engine is during the two revolutions of the crank (4 cycles), and then use another crankshaft position sensor to set a baseline for ignition (this is more accurate since the crank is moving faster and the slop of the cam drive is not a factor). I hope this may help otherwise the cam sensor may need to be turned 180 degrees.
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Supercharged)
I am not sure about the LS1, but many newly designed engines use the cam shaft sensor to let the computer know where the engine is during the two revolutions of the crank (4 cycles), and then use another crankshaft position sensor to set a baseline for ignition (this is more accurate since the crank is moving faster and the slop of the cam drive is not a factor). I hope this may help otherwise the cam sensor may need to be turned 180 degrees.
But we didn´t touch both.
Can it be that the cam position sensor needs to be turned 180 degrees, even though we didn´t touch it??
Turn it 180° ?? Can that be done?? Can it be needed??
Just looked into the service manual, I don´t think I can turn the cam pos. sensor 180°!?!
Can the cam be the wrong part?!?!?!?
I read the engine doesn´need the cam pos. sensor to run, so it should work without the sensor`??? But maybe it doesn´t run because it get´s the wrong readings??
It really looks like the ignition is 180° off ?!?!?!?!?!?!?!?!
Michael
[Modified by Austrian Vette, 7:36 PM 3/9/2002]
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Buckmaster)
Damn Michael...can't answer this :( But up to the top. Maybe some tuners will chime in like ARE, LG, Speed, etc. Good luck..not a good feeling :(
I don´t understand what´s going on in that engine?!?!?
Burning Brakes
Joined: Aug 2000
Posts: 912
Likes: 1
From: Clinton Twp. MI USA mi
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
Pretty slow on the forum right now, wish I could help, but you already know more than I do. Didnt mean to psyche you out seeing a new post, just my condolences(sympathy). Dam I cant spel.
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (ZO6LS6)
AV, no pro, but sounds like the NEW PCM is/was not programmed properly............ :confused:
I think (not sure) even a not good programmed PCM will not ignite Cyl. #6 when #1 is at compression.
Also I think that is not dialed in from the PCM.
First thing I did, was change back to the stock PCM, but when i crank the engine and it did the same.
Thanks for the reply anyway, I appreciate all help I can get!!!
BTW, I still have the timing chain housing off and the #1 and #6 sparks out, so I can look when they ignite.
Whenever the #1 Cyl. has the compr. then #6 plug ignites.
Did swap the PCM´s back and forth, but they don´t change anything.
At least the stock PCM should do right if it is PCM related?!?
I will not install the timing chain housing, pulleys, alternator, throttlebody and all other parts again bevore I see that the #1 plug ignites when the #1 Cyl. is on compression.
Michael
[Modified by Austrian Vette, 8:48 PM 3/9/2002]
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
A guy at LS1tech.com said the coil packs could be swapped.
That would decare why the firing is 180° off.
Is that possible???
Also will that react like it does when you swap the coil packs??
Just talked to my mechanic and he sais he doesn´t think he meixed it up as the wiring has given lengths and that makes it impossible to swap the coil packs.
Is that correct??
Michael
[Modified by Austrian Vette, 9:26 PM 3/9/2002]
That would decare why the firing is 180° off.
Is that possible???
Also will that react like it does when you swap the coil packs??
Just talked to my mechanic and he sais he doesn´t think he meixed it up as the wiring has given lengths and that makes it impossible to swap the coil packs.
Is that correct??
Michael
[Modified by Austrian Vette, 9:26 PM 3/9/2002]
Burning Brakes
Joined: Sep 2001
Posts: 1,173
Likes: 1
From: Aguila AZ
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
Michael,
All you have to do is exchange the right valve cover w/ coil packs with the left valve cover w/ coil packs and everything will work correctly... There is nothing wrong with your PCM that would cause this problem.
Shirl :D
All you have to do is exchange the right valve cover w/ coil packs with the left valve cover w/ coil packs and everything will work correctly... There is nothing wrong with your PCM that would cause this problem.
Shirl :D
Racer
Joined: Aug 1999
Posts: 324
Likes: 0
From: 26 NM out the 304 radial of the ORD VOR Illinois
Re: *need urgent help* engine doesn´t run after head/cam install (MrEracer)
Maybe the wiring harness was flipped over on the reinstall and the coil packs are hooked up to the wrong wiring plugs.
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (MrEracer)
Michael,
All you have to do is exchange the right valve cover w/ coil packs with the left valve cover w/ coil packs and everything will work correctly... There is nothing wrong with your PCM that would cause this problem.
Shirl :D
All you have to do is exchange the right valve cover w/ coil packs with the left valve cover w/ coil packs and everything will work correctly... There is nothing wrong with your PCM that would cause this problem.
Shirl :D
Or am I wrong??
Michael
Le Mans Master
Joined: Jun 1999
Posts: 5,237
Likes: 1
From: Newport Michigan
CF Pit Crew
Cruise-In I Veteran
Cruise-In II Veteran
Almost CI III Veteran
Cruise-In IV Veteran
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
Swapping coil packs would not cause this problem. The PCM sequences the coil firing based on crank position and cam position sensors. As long as the coil packs are plugged into the correct connectors for each cylinder, you should be fine. And as cyl 1 and cyl 6 are are opposite banks, you can't accidently mis connect them.
The LS1 firing order is 1-8-7-2-6-5-4-3 , so the fact that 6 is firing when you expect 1 to fire certainly points to the cam signal being out of phase. The connector for the cam position sensor should be keyed such that it can only be installed one way. You may want to check to make sure it wasn't connected backward inadvertantly - depending on what type of sensor is used, hooking it up backwards could give you an opposite phase voltage signal that would result in the PCM getting the incorrect cam position information.
The LS1 firing order is 1-8-7-2-6-5-4-3 , so the fact that 6 is firing when you expect 1 to fire certainly points to the cam signal being out of phase. The connector for the cam position sensor should be keyed such that it can only be installed one way. You may want to check to make sure it wasn't connected backward inadvertantly - depending on what type of sensor is used, hooking it up backwards could give you an opposite phase voltage signal that would result in the PCM getting the incorrect cam position information.
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Supercharged)
Maybe the wiring harness was flipped over on the reinstall and the coil packs are hooked up to the wrong wiring plugs.
But he sais, he dosn´t think he swapped the wiring, because the passenger side wiring is longer as it goes to the throttle body. or something????
Michael
[Modified by Austrian Vette, 9:43 PM 3/9/2002]
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (70L46)
Swapping coil packs would not cause this problem. The PCM sequences the coil firing based on crank position and cam position sensors. As long as the coil packs are plugged into the correct connectors for each cylinder, you should be fine. And as cyl 1 and cyl 6 are are opposite banks, you can't accidently mis connect them.
The LS1 firing order is 1-8-7-2-6-5-4-3 , so the fact that 6 is firing when you expect 1 to fire certainly points to the cam signal being out of phase. The connector for the cam position sensor should be keyed such that it can only be installed one way. You may want to check to make sure it wasn't connected backward inadvertantly - depending on what type of sensor is used, hooking it up backwards could give you an opposite phase voltage signal that would result in the PCM getting the incorrect cam position information.
The LS1 firing order is 1-8-7-2-6-5-4-3 , so the fact that 6 is firing when you expect 1 to fire certainly points to the cam signal being out of phase. The connector for the cam position sensor should be keyed such that it can only be installed one way. You may want to check to make sure it wasn't connected backward inadvertantly - depending on what type of sensor is used, hooking it up backwards could give you an opposite phase voltage signal that would result in the PCM getting the incorrect cam position information.
So what else besides swapping the coil packs could cause the 180° firing failure.
Can it be that the cam is wrong somehow, so the sensor gets wrong info??
Michael
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
That is the times that I wished I would live in US, have a good tuner install
all parts for me and have me sleeping good at night.
:cry :cry :cry
Michael
all parts for me and have me sleeping good at night.
:cry :cry :cry
Michael
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
Just in case the wring is correct,
can deconnect the coil packs from the wiring and swap them from drivers side to passenger side and vice versa bring me the firng like I have it now (Nr.6 instead Nr.1)??
Or work both coilpacks on both sides??
[Modified by Austrian Vette, 11:10 PM 3/9/2002]
can deconnect the coil packs from the wiring and swap them from drivers side to passenger side and vice versa bring me the firng like I have it now (Nr.6 instead Nr.1)??
Or work both coilpacks on both sides??
[Modified by Austrian Vette, 11:10 PM 3/9/2002]
Drifting
Joined: Oct 2001
Posts: 1,366
Likes: 0
From: America
Re: *need urgent help* engine doesn´t run after head/cam install (Austrian Vette)
Michael, as I said before no pro, (near idiot staus).........after reading the questions and hearing the problem..........unless the LS1/LS6 engines are SO different than ythe old CSB's of old........the only thing I can see LEFT is the timing gear on the crank & cam are 180 off.........
If this is not the problem, I am at a loss.
I see no other way you could have the 1 & 6 cylinders fing in that order........
Old timers don't understand newfangled crap....... :rolleyes:
If this is not the problem, I am at a loss.
I see no other way you could have the 1 & 6 cylinders fing in that order........
Old timers don't understand newfangled crap....... :rolleyes:
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,683
Likes: 0
From: Austria
Re: *need urgent help* engine doesn´t run after head/cam install (ZO6LS6)
Michael, as I said before no pro, (near idiot staus).........after reading the questions and hearing the problem..........unless the LS1/LS6 engines are SO different than ythe old CSB's of old........the only thing I can see LEFT is the timing gear on the crank & cam are 180 off.........
If this is not the problem, I am at a loss.
I see no other way you could have the 1 & 6 cylinders fing in that order........
Old timers don't understand newfangled crap....... :rolleyes:
If this is not the problem, I am at a loss.
I see no other way you could have the 1 & 6 cylinders fing in that order........
Old timers don't understand newfangled crap....... :rolleyes:
The timing gears are lined up when the #1 has compression, so that should be the correct #1 firing possition and the gears seem to be correct.
It´s only that the #6 plug fires instead that damn #1 plug and vice versa.