Notices
944 Turbo and Turbo-S Forum 1982-1991
Sponsored by:
Sponsored by: Clore Automotive

What would cause no spark

Thread Tools
 
Search this Thread
 
Old 03-27-2010 | 06:34 PM
  #1  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default What would cause no spark

I just put on a new turbo, maf, and chips and now I'm having trouble starting. The car will crank and I'm getting ~43psi on the fuel rail but no spark. The tach bounces slightly, maybe up to 200rpm. My rotor looked a little worn, but not bad enough for the car not to start. My battery was a little low, but I put some jumper cables on it and it did the same thing. I have it charging now. What sensors could be bad if the car is getting fuel but not getting spark?
Old 03-27-2010 | 06:49 PM
  #2  
carlege's Avatar
carlege
Drifting
 
Joined: May 2009
Posts: 2,530
Likes: 1
From: Atlanta, Ga
Default

got any info on the MAF turbo and Chips? all the spark wires hooked up correctly?
Old 03-27-2010 | 06:57 PM
  #3  
fast951's Avatar
fast951
Addict
Rennlist Member


Rennlist
Site Sponsor

 
Joined: Mar 2002
Posts: 6,885
Likes: 37
From: Atlanta
Default

If you are getting fuel (Injectors firing) but no spark, it can be the KLR or the final ignition driver in the DME.

If you are not getting spark, disconnect the fuse on the fuel pump so you do not flood the engine. Use a LED or Noid light on the injectors connector to verify they are firing. Also, you can use the same LED across the wires on the coil to see if the coil is getting a signal. This will help you determine which component (DME/KLR or coil,..) is at fault.
__________________
John
Email
www.vitesseracing.com
Old 03-27-2010 | 07:41 PM
  #4  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

Originally Posted by fast951
If you are getting fuel (Injectors firing) but no spark, it can be the KLR or the final ignition driver in the DME.

If you are not getting spark, disconnect the fuse on the fuel pump so you do not flood the engine. Use a LED or Noid light on the injectors connector to verify they are firing. Also, you can use the same LED across the wires on the coil to see if the coil is getting a signal. This will help you determine which component (DME/KLR or coil,..) is at fault.
Thanks John. I'll double check the connectors at the DME and KLR one more time and try again once the battery is charged. If it still isn't starting I'll use your method to check the wires.
Old 03-29-2010 | 03:33 PM
  #5  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

I checked the fuel injector wires and spark plug wires with a light with the battery charged and I got a signal on both sets. This leads me to believe injectors or plugs. I have spare injectors and was going to try them anyway. I pulled the dme relay and cranked the engine to relieve the pressure from the rail and the rail held 43 psi. Faulty injectors sound like a safe bet?
Old 03-29-2010 | 04:06 PM
  #6  
911racer's Avatar
911racer
Rennlist Member
 
Joined: Oct 2003
Posts: 1,356
Likes: 3
From: Ohio
Default

Has the car been sitting ?

I have, this year, had to spike my injectors with 12v straight from the battery to bring them back to life on a car that had been sitting. They did not click the first 3 or 4 times I hit them, but after a few times they were clicking like they should.

Ed
Old 03-29-2010 | 04:11 PM
  #7  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

Car hasn't been sitting but the injectors have. Did you do this with the injectors installed? Anyone else have to do this?
Old 03-29-2010 | 04:16 PM
  #8  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

btw injectors are seimens 55lb
Old 03-29-2010 | 04:33 PM
  #9  
fast951's Avatar
fast951
Addict
Rennlist Member


Rennlist
Site Sponsor

 
Joined: Mar 2002
Posts: 6,885
Likes: 37
From: Atlanta
Default

Read the spark plugs. If they have fuel on them the injectors are firing. Of course too much fuel, it'll flood and will not start..
Old 03-29-2010 | 04:43 PM
  #10  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

Thanks
Old 03-29-2010 | 06:44 PM
  #11  
rlm328's Avatar
rlm328
Rennlist Member
 
Joined: Aug 2007
Posts: 6,305
Likes: 309
From: Houston, Texas
Default

Reference sensors. If you replaced the turbo you had the intake manifold off. Make sure the references sensors are connected and that the O2 sensor plug is connected, although the car will start witout the O2 sensor it has difficulty idling. But if it is no spark I would trace out my reference sensors.
Old 03-29-2010 | 07:33 PM
  #12  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

Car works. I checked the plugs and they were clean so I replaced the injectors and it started right up.
Old 03-29-2010 | 07:53 PM
  #13  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

If someone wants the 55lb injectors that didn't fire to try to fix or send off to be fixed/rebuilt send me shipping and they're yours.
Old 03-29-2010 | 08:07 PM
  #14  
CPR's Avatar
CPR
Race Director
 
Joined: Jul 2008
Posts: 11,218
Likes: 3
From: Yorktown, Virginia
Default

"What would cause no spark ?"


Some women say it is too much whiskey.....
Old 03-29-2010 | 08:22 PM
  #15  
odb812's Avatar
odb812
Thread Starter
Burning Brakes
 
Joined: Jul 2005
Posts: 951
Likes: 0
From: San Rafael, CA
Default

Originally Posted by CPR
"What would cause no spark ?"


Some women say it is too much whiskey.....
in some cases it's not enough


Quick Reply: What would cause no spark



All times are GMT -3. The time now is 06:26 PM.