No spark/low key on voltage on carb swap
02-18-23, 03:59 PM
#1
Full Member
Thread Starter
No spark/low key on voltage on carb swap
I'll start with some information on the car before getting into my issue I have an NA '86 that I put a bridgeport Tii 4 port in with a 51 IDA. I went with a basic ignition setup with just a dizzy from an '85 with the electronic pickups and a pair of coils. For wiring I used pretty much none of the stock engine harness plugs apart from the alternator plug that I ran a temporary harness from the plugs to the back of the alternator, and I used the sensors on the pan. The rest of the harness is currently zip tied off to the side for now. I did however bolt up the ground on the main harness to the chassis, and I kept the stock ground that goes from the top of the trans to the firewall. For my power to coils I used the black and white wire off of the green test plug(on the left front of the motor near the battery) as my key on power.
I'm having a spark issue where I'm getting no spark. Through my troubleshooting I rewired from the coils to the j109s with a temporary wiring setup. I replaced both j109s with tested good ones, I also replaced the rotor and cap and wires. To no avail I then checked the power to the coils(which I should have done earlier on) I only had ~2.2V-2.4V at the coils and at the connections on the j109s. I then checked at the connection where my solder joint was and also a steady ~2.4V. I started to check a few other plugs throughout the engine bay with key on and all of them were ~2.4V, which from my experience is way low with them normally being battery voltage or ~12V. I hooked up a wire directly from the positive terminal to the coils just as a proof of concept and I was getting spark, which obviously points to that being my issue. I checked both grounds I referenced earlier and they are true grounds.
My question is basically is why is it only 2.4V with key on from those wires? Does it have anything to do with the a majority of the harness not being plugged in in the engine bay? Let me know what you guys think, and feel free to ask anything questions to get more information needed to help figure out what's going on.
I'm having a spark issue where I'm getting no spark. Through my troubleshooting I rewired from the coils to the j109s with a temporary wiring setup. I replaced both j109s with tested good ones, I also replaced the rotor and cap and wires. To no avail I then checked the power to the coils(which I should have done earlier on) I only had ~2.2V-2.4V at the coils and at the connections on the j109s. I then checked at the connection where my solder joint was and also a steady ~2.4V. I started to check a few other plugs throughout the engine bay with key on and all of them were ~2.4V, which from my experience is way low with them normally being battery voltage or ~12V. I hooked up a wire directly from the positive terminal to the coils just as a proof of concept and I was getting spark, which obviously points to that being my issue. I checked both grounds I referenced earlier and they are true grounds.
My question is basically is why is it only 2.4V with key on from those wires? Does it have anything to do with the a majority of the harness not being plugged in in the engine bay? Let me know what you guys think, and feel free to ask anything questions to get more information needed to help figure out what's going on.
Thread
Thread Starter
Forum
Replies
Last Post
wjp005
3rd Generation Specific (1993-2002)
4
04-03-07 06:32 AM
dlbchik
2nd Generation Specific (1986-1992)
12
12-07-02 06:41 PM