LS6 Cobra
Thread Starter
Staging Lane
Joined: Oct 2004
Posts: 57
Likes: 0
From: England UK
LS6 Cobra I have recently tried to start my LS engine which is installed in a Cobra Kit Car, and have used a Baker Lim module with this installation.
I am pretty sure that the module is all wired in correctly. Although the engine is an LS6 I am using an LS1 PCM and wiring loom (for the mechanical throttle), from a 1999 vehicle.
I have got a spark at the engine, and fuel as far as the fuel rails, but there is no sign of life. This makes me think that the fuel enable signal is not reaching the injectors, and the VATs signal seems to be the starting point.
Could you tell me how I can test this theory, and if there any other tests I can carry out.
I am pretty sure that the module is all wired in correctly. Although the engine is an LS6 I am using an LS1 PCM and wiring loom (for the mechanical throttle), from a 1999 vehicle.
I have got a spark at the engine, and fuel as far as the fuel rails, but there is no sign of life. This makes me think that the fuel enable signal is not reaching the injectors, and the VATs signal seems to be the starting point.
Could you tell me how I can test this theory, and if there any other tests I can carry out.
im not too sure on this but i dont believe that an ls1 pcm woul be the cause cause the eingines are basically identical extenally. try checking to see if all of your grounds are hooked up. thats the only thing i can think of. hope you get it running...
TECH Enthusiast
Joined: Jun 2004
Posts: 544
Likes: 0
From: Itasca, IL
Have you disabled the VATs on the PCM? My car would not start without disableing it. Other than that check all the grounds and fuses. I had one fuse blown, and I spent weeks trying to figure out why it wasnt working. Im not sure how you car is wired, but thats where I would say to look.
On The Tree
Joined: Jul 2005
Posts: 161
Likes: 2
From: Wokingham, United Kingdom
Paul,
I'm as far through as you yet, however from what I've read here so far, my understanding is that VATS will let you start the car but only for 2-3 seconds - might be worth removing the baker module to start with?
Jim
I'm as far through as you yet, however from what I've read here so far, my understanding is that VATS will let you start the car but only for 2-3 seconds - might be worth removing the baker module to start with?
Jim
Trending Topics
vats cuts power to the started and fuel pump..if the vats is on..nothign will happen when you turn the key..you have to get that **** tuned out..i just had to get a new key cause the original key took a **** on me and the vats came on.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Staging Lane
Joined: Oct 2004
Posts: 57
Likes: 0
From: England UK
Thanks for all the replies. I have discussed the issue with Baker Electronix, and it does not seem like it is the VATs causing the problem.
I am going to take out oune of the injectors and turn the engine over, (carefully) and see if fuel is getting into the engine.
If it isn't, as I understand it the PCM just switches the earth on and off, so I will check whether it is doing this or not.
I think I will just have to take the loom apart again and follow the wires back.
I am going to take out oune of the injectors and turn the engine over, (carefully) and see if fuel is getting into the engine.
If it isn't, as I understand it the PCM just switches the earth on and off, so I will check whether it is doing this or not.
I think I will just have to take the loom apart again and follow the wires back.
That is a sweet looking project. I bet that little car is going to fly...and handle like crazy. Good luck with the VATS and when I get home tonight I will look through my GM manual and see if I can help you out. I have the 3 Volume GM F-body service manual for 1999 so maybe I can help you figure out what to do. I know that it is a combination of the BCM and PCM. The BCM has the fuel enable circuit in it which looks for the proper ignition key (with the little resistor in it) and then will allow the PCM to enable the fuel. Like you said, I think it is just an earth ground applied to the PCM.
Good luck
Josh
Good luck
Josh
Thread Starter
Staging Lane
Joined: Oct 2004
Posts: 57
Likes: 0
From: England UK
Josh,
Thanks for your reply. I should have a better idea what's going on once I have taken out the injector and tested it.
I look forward to hearing from you if you find anything.
The kit is built by a company in the UK called Gardner Douglas, (http://www.gdcars.com/).
It should be pretty quick as all up it will weigh about 950 kilos or less than a ton. Once this LS6 runs it should have plenty of power and an excellent power to weight ratio!
Paul
Thanks for your reply. I should have a better idea what's going on once I have taken out the injector and tested it.
I look forward to hearing from you if you find anything.
The kit is built by a company in the UK called Gardner Douglas, (http://www.gdcars.com/).
It should be pretty quick as all up it will weigh about 950 kilos or less than a ton. Once this LS6 runs it should have plenty of power and an excellent power to weight ratio!
Paul
OK, I just finished looking through my manual. The Theft Deterrent Fuel Enable Signal leaves the BCM on connector C2 pin D8 (not important to you because you are not using it) and goes to the PCM on C2 (red) pin 30. I have not figured out what the signal is yet but that is the pin. It is quite possible that it is just a ground signal that enables the PCM to drive the injectors. Have you verified that the fuel pump is coming on and giving 58 PSI?
I will keep digging and see if I can determine what 'signal' the PCM is looking for fromt he BCM.
Good luck
Josh
I will keep digging and see if I can determine what 'signal' the PCM is looking for fromt he BCM.
Good luck
Josh
Thread Starter
Staging Lane
Joined: Oct 2004
Posts: 57
Likes: 0
From: England UK
The injectors have a constant power supply. As I understand it the signal from the PCM provides the earth supply to complete the circuit.
None of the injectors are not getting this signal. The fuel pump relay is all OK, and there is fuel in the fuel rails.
I am wondering if the camshaft on crankshaft sensors could be to balme, but I am not sure how to check them. Any ideas?
None of the injectors are not getting this signal. The fuel pump relay is all OK, and there is fuel in the fuel rails.
I am wondering if the camshaft on crankshaft sensors could be to balme, but I am not sure how to check them. Any ideas?
On The Tree
Joined: May 2004
Posts: 161
Likes: 0
From: London, UK
Just a note for our American cousins, Gardner Douglas has an American arm www.gdcarsusa.com
I've got a GD427 with an LS1 in it and yes, they are very quick!!
I've got a GD427 with an LS1 in it and yes, they are very quick!!
Well, I am back at work so don't have the manuals infront of me. When I get home tonight I will see if there is a precedure for bench-checking those sensors. If you can get your hands on some you could try to switch them out. I see them on ebay for 10-20 bucks(US) all the time.
On The Tree
Joined: May 2004
Posts: 161
Likes: 0
From: London, UK
Paul,
Sorry we couldn't get it going today. If it's any consolation, mine flew on the way home (calculated about 15mpg, but that figure isn't quite correct - I'll need another fill up before I can get an accurate figure).
Racking my brains to think of what the problem could be. I'm sure it's something simple as the fuel pump seems to be working OK, and that is triggered by the PCM. Will let you know if I think of anything in the meantime...
Robin
Sorry we couldn't get it going today. If it's any consolation, mine flew on the way home (calculated about 15mpg, but that figure isn't quite correct - I'll need another fill up before I can get an accurate figure).
Racking my brains to think of what the problem could be. I'm sure it's something simple as the fuel pump seems to be working OK, and that is triggered by the PCM. Will let you know if I think of anything in the meantime...
Robin
I had a bad cam shaft sensor, and the motor still ran. It ran like garbage and spit fire out the exhaust, but it ran. I would think the crank sensor would be more of a suspect. The crank senors just times the #1 cylinder, and the cam senor takes over the timing for the rest of the cylinders. Check that all grounds are good also.