Not getting any fire to the dist.....HELP
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Professional
Joined: Feb 2009
Posts: 229
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From: Mocksville,NC
The first thing you need to establish (visually) is what ignition system you have. Because, there are three possibilities.
A) You could have LEAN BURN (disaster)
http://www.allpar.com/mopar/lean-burn.html
B) The split system:
""For vehicles built from 1984 through 1987, the ECU is actually divided into two parts. This was done to isolate the electrical noise and interference generated by the power module from the passenger compartment. The Logic Module is located inside the passenger compartment, usually behind the front passenger-side kick panel which is below the dashboard and glove compartment. The Power Module is located in the engine compartment in the left, front fender next to the battery. The intake to the air box is connected to the power module so that the engine pulls cool air through it from behind the front bumper. This keeps the module cool (it has several transistor drivers and regulators) and also supplies cool air to the engine intake. It is important not to change this since the power module could potentially overheat when the car is running, but not moving.""
These look like the later SMEC controllers used in '88/89 and is in the LHS fender.
http://www.knizefamily.net/minimopar/ecu/index.html
C) Or you could have the preferred one which is the 4 pin ECU (with ballast resistor) and is the one you should switch to (if you want it to run properly) if you have the other BS.
http://www.allpar.com/fix/electronic-ignition.html
A) You could have LEAN BURN (disaster)
http://www.allpar.com/mopar/lean-burn.html
B) The split system:
""For vehicles built from 1984 through 1987, the ECU is actually divided into two parts. This was done to isolate the electrical noise and interference generated by the power module from the passenger compartment. The Logic Module is located inside the passenger compartment, usually behind the front passenger-side kick panel which is below the dashboard and glove compartment. The Power Module is located in the engine compartment in the left, front fender next to the battery. The intake to the air box is connected to the power module so that the engine pulls cool air through it from behind the front bumper. This keeps the module cool (it has several transistor drivers and regulators) and also supplies cool air to the engine intake. It is important not to change this since the power module could potentially overheat when the car is running, but not moving.""
These look like the later SMEC controllers used in '88/89 and is in the LHS fender.
http://www.knizefamily.net/minimopar/ecu/index.html
C) Or you could have the preferred one which is the 4 pin ECU (with ballast resistor) and is the one you should switch to (if you want it to run properly) if you have the other BS.
http://www.allpar.com/fix/electronic-ignition.html
Registered User
Joined: Sep 2009
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I am not getting fire to the coil. I have replaced the cap, coil, wires, plugs, optima battery, and a new electronic single coil plate distributor with no vaccuum advance. My SCC has two wiring harnesses coming off it one has 12 and the other 8. The truck started yesterday before and after I put in the new distributor, but once I turned it off, it stopped for good. At one point there was a spark from the distributor and there was spark on the first plug. then it just stopped. Is the SCC the next thing to replace? What about the wiring? Do they have a harness just for that?
Registered User
Joined: Sep 2009
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Ok, I am reading my bible here and it tells me to unplug the 10 way connector (mine has two plugs, one with 8 and one with 12, go figure) from the bottom of the Spark Control Computer. Then it says turn the key to ON and hold the coil wire 1/4" from a good ground.
Here is the part that I cannot understand it says
"With battery current flowing to the coil negative terminal,"???? "intermittently short the coil to a ground".
So it needs to be on, not running, and I need to take a wire and hold it from the negative to a ground???? That doesn't make sense and I don't want to run a line from the positive to the negative on the coil, even if only intermittently, I imagine?
Here is the part that I cannot understand it says
"With battery current flowing to the coil negative terminal,"???? "intermittently short the coil to a ground".
So it needs to be on, not running, and I need to take a wire and hold it from the negative to a ground???? That doesn't make sense and I don't want to run a line from the positive to the negative on the coil, even if only intermittently, I imagine?
Champion
Joined: Mar 2009
Posts: 2,639
Likes: 4
From: Bent Mountain Va
You obviously have some system other than a standard SCC if you have an 8 and 12 pin connector instead of a single 10 pin. To trouble shoot your system I would suggest correctly identifying the system you are working on first. Where is this SCC located in the engine bay and does it have a ballast resistor? What is written on the outside of the SCC?
Registered User
Joined: Sep 2009
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Ok, well I went back and double checked this morning. Under the driver's fender there are two wiring harnesses hooked up to a computer. The closest to the firewall has 14 connections, and the one closest to the front bumper has 10. I do not see a ballast resistor on any of the warness at the computer or on the computer itself. It does have the air inlet to keep the computer cool, so I imagine I am on the right track and that this is the computer I am looking at.
Champion
Joined: Mar 2009
Posts: 2,639
Likes: 4
From: Bent Mountain Va
Lilredex posted this earlier. It explains what system you may have. http://www.knizefamily.net/minimopar/ecu/index.html
When you go to the above link click on the 1985-1987 TBI power module or 1985-1987 turbo power module. They both have a 10 pin and a 12 pin connector.
When you go to the above link click on the 1985-1987 TBI power module or 1985-1987 turbo power module. They both have a 10 pin and a 12 pin connector.
Last edited by SEAL; Sep 24, 2009 at 04:06 PM.
Champion
Joined: Mar 2009
Posts: 2,639
Likes: 4
From: Bent Mountain Va
Charlie
I don't know if he has a TBI or carburetor as he has not said one way or the other. Were there any TBI engines for 1985-1987? I don't know. I also don't know if his system is stock. What I do know is that the systems I tried to point him to were used in 1985-1987 and seem to match what he is describing, no matter what they are called. From what you have posted you seem to have the same setup in the same year as he does Charlie. What system is in yours?
I don't know if he has a TBI or carburetor as he has not said one way or the other. Were there any TBI engines for 1985-1987? I don't know. I also don't know if his system is stock. What I do know is that the systems I tried to point him to were used in 1985-1987 and seem to match what he is describing, no matter what they are called. From what you have posted you seem to have the same setup in the same year as he does Charlie. What system is in yours?