LT1 Ignition problem

Jason Leindecker · 01-25-2009, 04:31 PM

I have been using the Accel DFI gen 7 for 3 seasons now and have never encountered a real problem before. This past season installed a MSD billet distributor on my LT1. When the engine is cold it turns over several times before firing but once fired its OK. The car will run and idol all day as long as you keep the engine running. Once you shut the car off and if any heat is still in the motor (at least recognized by the temp gage) when you go to fire the motor again it turns over really hard, and I have to open the throttle body all the way for it to fire. It idols for several seconds and shuts off. When it shuts off it does not stumble or fade away it just shuts off like a kill switch is being thrown. If you give it any throttle during this brief period of idol the tach needle goes crazy and is not reading true RPM's and then it dies. I have checked ground wires, changed the ECM, changed coils, and changed ignition modules. I have been pulling my hair out, what's left anyway, trying to figure this out. If you can offer any help please do.

Woodro Josey · 01-25-2009, 06:07 PM

I hate to tell you this, but it sounds like the MSD Optispark-distributor! I have heard of some problems with these units!

Rich Biebel · 01-25-2009, 06:54 PM

Hello Jason...remember me? I ran the stock distributer...just removed all the optispark stuff and added the MSD cap and rotor. I used a crank trigger and did not feed that trigger signal into the ECU. I ran the timing locked out just for simplicity and ran an MSD digital 6 and also an MSD 7Al2 for a while. I have no experience with the MSD distributer for an LT-1 but it sure does sound like it is the trouble as Woodro says.....

Ed Wright · 01-26-2009, 12:05 PM

I've also seen numerous problems like that with the MSD Optispark. I replace the plastic pegs on the stock GM rotor with aluminium 1/8" pop rivets to prevent slinging the blades off the rotor, that is the only problem I ever had with the factory GM pieces. I later went to an MSD crank trigger for the signal and only used the Optispark for the cap and rotor.

Tom Nolan · 01-26-2009, 12:16 PM

Sorry to say but the MSD piece is junk! I have sold several of these units and 3 out of 5 were screwed right out of the box! QC on these must not exsist!

Jason Leindecker · 01-26-2009, 08:38 PM

Hello Rich I sure do remember you how are you. I should have bought your stocker instead of fiddling with this P.O.S. Anyway I had 1 good run on the car at the grove running 8 tenths under in E weight and I thought I was in the right direction. Then on the second trip to a test and tune this issue turned up just out of the blue. Figuring the MSD was really the only change I had made to the car I sent the distributor back to MSD, almost against thier will, and they said they would replace the optical eye. Got the distributor back and nothing changed so I figured it must have been something else causing this problem. I was not aware of any complaints about this distributor at the time or I would have just put a crank trigger on it to begin with. Thank you guys for taking the time to respond to this thread. I do appreciate it.

01-25-2009, 04:31 PM	#1
Jason Leindecker Junior Member Join Date: Feb 2006 Location: Center Valley, PA Posts: 18 Likes: 0 Liked 0 Times in 0 Posts	LT1 Ignition problem I have been using the Accel DFI gen 7 for 3 seasons now and have never encountered a real problem before. This past season installed a MSD billet distributor on my LT1. When the engine is cold it turns over several times before firing but once fired its OK. The car will run and idol all day as long as you keep the engine running. Once you shut the car off and if any heat is still in the motor (at least recognized by the temp gage) when you go to fire the motor again it turns over really hard, and I have to open the throttle body all the way for it to fire. It idols for several seconds and shuts off. When it shuts off it does not stumble or fade away it just shuts off like a kill switch is being thrown. If you give it any throttle during this brief period of idol the tach needle goes crazy and is not reading true RPM's and then it dies. I have checked ground wires, changed the ECM, changed coils, and changed ignition modules. I have been pulling my hair out, what's left anyway, trying to figure this out. If you can offer any help please do. __________________ Jason Leindecker

01-25-2009, 06:07 PM	#2
Woodro Josey Senior Member Join Date: Jul 2007 Posts: 805 Likes: 0 Liked 3 Times in 1 Post	Re: LT1 Ignition problem I hate to tell you this, but it sounds like the MSD Optispark-distributor! I have heard of some problems with these units! __________________ Woodro Josey 2002 STK

01-25-2009, 06:54 PM	#3
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: LT1 Ignition problem Hello Jason...remember me? I ran the stock distributer...just removed all the optispark stuff and added the MSD cap and rotor. I used a crank trigger and did not feed that trigger signal into the ECU. I ran the timing locked out just for simplicity and ran an MSD digital 6 and also an MSD 7Al2 for a while. I have no experience with the MSD distributer for an LT-1 but it sure does sound like it is the trouble as Woodro says..... __________________ Rich Biebel S/C 1479 Stock 147R

01-26-2009, 12:05 PM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: LT1 Ignition problem I've also seen numerous problems like that with the MSD Optispark. I replace the plastic pegs on the stock GM rotor with aluminium 1/8" pop rivets to prevent slinging the blades off the rotor, that is the only problem I ever had with the factory GM pieces. I later went to an MSD crank trigger for the signal and only used the Optispark for the cap and rotor. __________________ Ed Wright 4156 SS/JA

01-26-2009, 12:16 PM	#5
Tom Nolan Member Join Date: Dec 2001 Location: Lacombe, Alberta, Canada Posts: 182 Likes: 0 Liked 64 Times in 11 Posts	Re: LT1 Ignition problem Sorry to say but the MSD piece is junk! I have sold several of these units and 3 out of 5 were screwed right out of the box! QC on these must not exsist!

01-26-2009, 08:38 PM	#6
Jason Leindecker Junior Member Join Date: Feb 2006 Location: Center Valley, PA Posts: 18 Likes: 0 Liked 0 Times in 0 Posts	Re: LT1 Ignition problem Hello Rich I sure do remember you how are you. I should have bought your stocker instead of fiddling with this P.O.S. Anyway I had 1 good run on the car at the grove running 8 tenths under in E weight and I thought I was in the right direction. Then on the second trip to a test and tune this issue turned up just out of the blue. Figuring the MSD was really the only change I had made to the car I sent the distributor back to MSD, almost against thier will, and they said they would replace the optical eye. Got the distributor back and nothing changed so I figured it must have been something else causing this problem. I was not aware of any complaints about this distributor at the time or I would have just put a crank trigger on it to begin with. Thank you guys for taking the time to respond to this thread. I do appreciate it. __________________ Jason Leindecker