Installed new head gasket on a 7mge and now the ignition doesn't work

dgee509 · 04-12-2011, 01:53 AM

I installed a new head gasket on my 1990 model supra non Turbo and now I can't start the car. When I turn the key to the start position all that comes on is the air bag light. I am measuring 12 volts across my battery terminals, but I'm not getting power to anything except my headlights and dome lights. Can anyone please guide me in the right direction to fix this problem? Thanks for any help you can give.

Green7mgte · 04-12-2011, 02:49 AM

sounds like you missed a ground.

ground strap from engine rear side.

pinched wire, bad or forgotten ground, or connector forgotten. power and ground at the coil and then work backwards

dgee509 · 04-12-2011, 03:27 AM

Thanks for the info Green7mgte. That was my original thought also. I had two ground wires coming from the starter area hooked to an intake bolt when I took it apart and I hooked them back to the same bolt and when I had the ignition problem I checked them to ground and it ohm'd out good. Also there is a white 4-prong female plug hanging from the harness in the area of the starter and I can't see anything it would plug in to. The starter seems to have all appropriate wires running to it. The thing that gets me is that with the key in the ON position my head lights and dome lights work, but my windshield wipers wont work or my ignition. And my gauges aren't showing that I have a charge on my battery... Would it still be a ground or a plug left disconnected? Maybe a bad relay? Thanks again for the help.

Green7mgte · 04-12-2011, 04:16 AM

yea, defiantly sounds like a missed ground / connector someplace buddy. something running to your fuses most likely since "everything" is off.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/

dgee509 · 04-14-2011, 03:07 AM

Thanks again for your help. I wound up tracing my ignition problem back to a blown AM1 fuse. I got the car turning over, but I still wasn't getting fire. I solved that problem when I discovered my intake can gear was 1 tooth out of time and my distributor was 180 degrees off. So now I have the car running, but I have my distributor adjusted all the way to one side of my adjustment and the car has a miss. I put new spark plugs in when I reinstalled the head, but there has been a lot of timing adjustment done since then. Do you think I could have fouled a plug in this process or do you think I am still having timing issues? Also, my oil pressure is reading very low at idle speed and increases to about 30 as I rev the motor. Is this normal?

04-12-2011, 01:53 AM	#1
dgee509 Stock Join Date: Apr 2011 Location: killen, al Posts: 16	Installed new head gasket on a 7mge and now the ignition doesn't work I installed a new head gasket on my 1990 model supra non Turbo and now I can't start the car. When I turn the key to the start position all that comes on is the air bag light. I am measuring 12 volts across my battery terminals, but I'm not getting power to anything except my headlights and dome lights. Can anyone please guide me in the right direction to fix this problem? Thanks for any help you can give.

04-12-2011, 02:49 AM	#2
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	sounds like you missed a ground. ground strap from engine rear side. pinched wire, bad or forgotten ground, or connector forgotten. power and ground at the coil and then work backwards __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 04-12-2011 at 02:59 AM.

04-12-2011, 04:16 AM	#4
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	yea, defiantly sounds like a missed ground / connector someplace buddy. something running to your fuses most likely since "everything" is off. http://www.cygnusx1.net/Supra/Library/TEWD/MK3/ __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 04-12-2011 at 04:24 AM.

04-14-2011, 03:07 AM	#5
dgee509 Stock Join Date: Apr 2011 Location: killen, al Posts: 16	got it running, but still not right Thanks again for your help. I wound up tracing my ignition problem back to a blown AM1 fuse. I got the car turning over, but I still wasn't getting fire. I solved that problem when I discovered my intake can gear was 1 tooth out of time and my distributor was 180 degrees off. So now I have the car running, but I have my distributor adjusted all the way to one side of my adjustment and the car has a miss. I put new spark plugs in when I reinstalled the head, but there has been a lot of timing adjustment done since then. Do you think I could have fouled a plug in this process or do you think I am still having timing issues? Also, my oil pressure is reading very low at idle speed and increases to about 30 as I rev the motor. Is this normal?

04-12-2011, 03:27 AM	#3
dgee509 Stock Join Date: Apr 2011 Location: killen, al Posts: 16	Thanks for the info Green7mgte. That was my original thought also. I had two ground wires coming from the starter area hooked to an intake bolt when I took it apart and I hooked them back to the same bolt and when I had the ignition problem I checked them to ground and it ohm'd out good. Also there is a white 4-prong female plug hanging from the harness in the area of the starter and I can't see anything it would plug in to. The starter seems to have all appropriate wires running to it. The thing that gets me is that with the key in the ON position my head lights and dome lights work, but my windshield wipers wont work or my ignition. And my gauges aren't showing that I have a charge on my battery... Would it still be a ground or a plug left disconnected? Maybe a bad relay? Thanks again for the help.