1985 Jeep CJ7 Function of the coil Pickup assembly

Tiny
WICKET
  • MEMBER
  • 1985 JEEP CJ7
  • 6 CYL
  • 4WD
  • MANUAL
  • 95,000 MILES
I have a completely original 85 Jeep CJ7 Lardeo. Recently, I installed a performance distributor from Davis Unified in Memphis, TN. The performance distributor is based on the GM HEI that combines the coil pack and distributor into one unit with a single wire hook-up. In comparison, the original Ford ignitiion system had a power wire for the coil and a seperate coil pick-up assembly that connected to the original Jeep wiring harness. The engine starts and runs. Ok on the new HEI distributor, but the computer systems that controls the metering rod in the carb has stoped working. After testing every system and finding no issues. With the enigine running I simply pluged the old distributor back into the wiring harness via the coil pick up assembly and grounded the unit to see the effect. The computer/metering rod started working. Question, is there a work-around to make the computer system work PROPERLY with the HEI distributor?
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Friday, July 9th, 2010 AT 3:50 PM

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Tiny
CJ MEDEVAC
  • EXPERT
See my profile and other CJ 5/7 Posts, I am not really up on the computer stuff on the later CJs. I have totally removed them ([computers] and rewired like earlier models) and used the "BETTER" '79 style carb (BBD) with no stepper motor (the stepper type usually gum up, and the computer controlled stuff fails to move + more expensive)

I will try to help you if I can, but I am really only familiar with Stock type ignition systems and YFs and BBDs. On Jeeps not real familiar with Chevy stuff

I answer lots of the CJ 5/7 questions, in both forums.

Is this one of those deals, that does not run the distributor off of the cam. But from a crankshaft sensor add on?

You said one wire--12Volts for coil power?

How does this NEW distributor use an "Ignition Module?". Jeep one or does it have its own?

They thought using a O2 sensor and a air/fuel gauge to help decide jetting on a Holley 390 CFM was "outrageous"----I believe your deal really tops mine!

The somewhat

Baffled

Medic

(I know CJs and with a little more info, may can still assist you!)
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Friday, July 9th, 2010 AT 10:58 PM
Tiny
WICKET
  • MEMBER
The distributor shaft connects to the cam just like the original design.

Yes, the HEI unit is a one wire connection(i.E. Power) and an optional tach connection.

I guess the ignition module is built-in. This an all in one design.
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Monday, July 12th, 2010 AT 10:30 AM
Tiny
CJ MEDEVAC
  • EXPERT
OK, I do not know if you have a manual w/ wire diagrams---Like I said, computers, in CJs is probably my worst weakness.

I am looking at diagram '82-'86 6 cylinder.

I can trace most of it but when it hits a connector, I cannot figure out its mate connector (if its the right mate)

So far, I have the original ignition module--2 wire bundles....one w/4 wires.....

1st 3 go to distributor uninterrupted

BLK w/ Grn tracer
Violet
Orange
Last (below), goes to the Neg side of coil, also splices into a connector which "control Vacuum solenoid" and "idle speed switch" are present in the same connector.
Green

Bundle "2" on Ignition module .....is 2 wires

RED (from module)

It travels to the Pos of Coil (as a resistance wire, THUS the NEED for a COIL, that says, "FOR USE EXTERNAL RESISTOR ONLY", IS YOUR COIL COMPATABLE TO THIS, OR DOES IT HAVE AN INTERNAL RESISTOR? WRONG!).......the other end goes to a connector (which I know goes to the "on" position of the ignition switch) [I do not know if it splices off to anything else along the way]....Diagram is vague at this connector

White on module/ changes to light blue at 1st connector (3 inches out) .....it goes into the same "vague" connector as "red" wire above

I will investigate my other manuals.......most have the exact same Diagrams....Just different sizes...and legibility...depending on how many times it was reproduced.....Give me some time.

I have the AMC 1979 Service Manual w/ wonderful diagrams.....but this was before computers!

Do you think your new setup will be any better than a "High Speed Coil"---And a "High Speed Distributor"----where part availability may be EZer and cheaper?

I am usually the "Trend Setter" w/ my Jeep (especially Fuel Economy Fads) I get the same Interrogation I'm giving you!

I have got many mechanical modifications (improvements to stock)---I have them on Walmart Album Sharing...so others could maybe use the ideas...I have at least 10 Jeep albums....I will send you a PM (private message) about them...When you respond

The Medic


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Monday, July 12th, 2010 AT 2:54 PM

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