TFI ignition upgrade
- Thread starter TerryMason
- Start date
That's why we say for the V-8 to use a '79 Ford F-150 with 302 V-8 engine for distributor parts,
Cap Adapter,
Distributor Cap,
Rotor...
OR, MSD p/n 8414 gives it all to you at once, and uses a premium cap...
MSD Ignition 8414 - MSD Cap-A-Dapts - summitracing.com
Attachments
Last edited by a moderator:
Bigf350sd
New member
Well, I would like some feedback here on this if I can get some. I unboxed my HEI "clone" cheap Dragon Fire distributor today and proceeded to check it out, gear hardness, length, cap for brass terminals and flaking electrode, etc...and found out a couple of things. First off, the gear was hardened, a drill bit wouldn't even scratch it, BUT...I had read that a factory gear wouldn't work on aftermarket distributors, but I got out the calipers, checked shaft diameters, and proceeded to remove the factory gear from my old points style distributor, and install it on the new HEI, and it fit like it was made for it! It was ever so slightly tight, took a couple of small taps to get it on, put in the new pin...PERFECT! Any ideas why this won't work? Second, I installed the dizzy in the 360 WITHOUT a gasket, after visually inspecting the length, and it appeared to seat fully into the engine, I couldn't get a small flat head screwdriver tip under it, and then I had up and down play in the shaft, somewhere in the range of 1/16 to 1/8 inch, so it was not tight against the pump, so again...I'm thinking PERFECT. Next, I moved to the cap itself, popped it off, brass terminals inside and out, and I couldn't even scratch the center electrode with a screwdriver, much less my fingernail, and the cap is RED in color, not black, so I think I'm good there also. The only thing I didn't get around to, was removing the module and checking for heat sink paste instead of dielectric grease, and running in the longer screw and grounding it externally. Once I get those 2 things checked/done, I think/HOPE I'm gonna be good on this thing, and dodged the bullet. Again, any ideas why the factory gear that fit seemingly perfect, (with the dimple on the rotor tip side) will not work? Please, if anyone has any ideas on the gear or any other thing I mentioned, or anything I forgot to mention, please, let me know! I don't want to risk hurting the engine with this thing. :???:
Well, I actually answered your questions on one of the other forums you posted on...
For the rest of the readers,
The early Delco breaker points distributor use the same size shaft as the later Delco HEI distributors,
SO,
As I've stated so many times before,
The Delco I-6 and V-8 Breaker Points distirbutor gears WILL FIT an GM HEI.
The fact that it fit your 'Dragon Fire' version is a fluke since many of the HEI Clones have under, or over sized shafts.
------------------------------
As we have established before,
The AMC Jeep/Motorcraft V-8 Gear will fit a GM HEI shaft also...
When this was just a 'Junk Yard' upgrade, many people just used the V-8 gear on the GM HEI distributor for the I-6 engines and it worked fine...
The ONLY gears that won't interchange with a GM/Delco HEI distributor with standard shaft is the AMC Jeep/Motorcraft I-6 Gears.
An AMC factory I-6 gear from '78 to '86 WILL NOT transfer directly onto a GM HEI distributor.
For the rest of the readers,
The early Delco breaker points distributor use the same size shaft as the later Delco HEI distributors,
SO,
As I've stated so many times before,
The Delco I-6 and V-8 Breaker Points distirbutor gears WILL FIT an GM HEI.
The fact that it fit your 'Dragon Fire' version is a fluke since many of the HEI Clones have under, or over sized shafts.
------------------------------
As we have established before,
The AMC Jeep/Motorcraft V-8 Gear will fit a GM HEI shaft also...
When this was just a 'Junk Yard' upgrade, many people just used the V-8 gear on the GM HEI distributor for the I-6 engines and it worked fine...
The ONLY gears that won't interchange with a GM/Delco HEI distributor with standard shaft is the AMC Jeep/Motorcraft I-6 Gears.
An AMC factory I-6 gear from '78 to '86 WILL NOT transfer directly onto a GM HEI distributor.
83CJ7258greatshape
New member
Terry,
Performed this upgrade on my 83 CJ7. WOW!!! Cannot believe the performance before and after. Never would have suspected I had an ignition problem. Had a rolling kind of idle at best along with the stalls, lousy acceleration, the hesitation, etc..
Just never wiould have suspected the ignition. I take my hat off to teamrush and you for posting.
Keep up the good work.
Tom
Performed this upgrade on my 83 CJ7. WOW!!! Cannot believe the performance before and after. Never would have suspected I had an ignition problem. Had a rolling kind of idle at best along with the stalls, lousy acceleration, the hesitation, etc..
Just never wiould have suspected the ignition. I take my hat off to teamrush and you for posting.
Keep up the good work.
Tom
azjpiper151
New member
Did this to my jeep and mad a great change. I still can not get the darn thing to rev over 3.5k. and is quite boggy and not as responsive as I would like. Any suggestions??
83CJ7258greatshape
New member
To the "won't rev over 3.5k" owner. Wouldn't be surprised if you had a crankcase ventilation problem.
Recommend switching the PCV valve to a "Breather cap / PCV valve" It's a breather cap (with wire mesh in cap) plus a pcv valve. Available at Autozone. Fits right on the ol' 258.
Mine works great.
Hope this helps.
Recommend switching the PCV valve to a "Breather cap / PCV valve" It's a breather cap (with wire mesh in cap) plus a pcv valve. Available at Autozone. Fits right on the ol' 258.
Mine works great.
Hope this helps.
azjpiper151
New member
Re: TFI ignition upgrade
<hr style="color: rgb(209, 209, 225);" size="1"> <!-- / icon and title --> <!-- message --> To the "won't rev over 3.5k" owner. Wouldn't be surprised if you had a crankcase ventilation problem.
Recommend switching the PCV valve to a "Breather cap / PCV valve" It's a breather cap (with wire mesh in cap) plus a pcv valve. Available at Autozone. Fits right on the ol' 258.
Mine works great.
Hope this helps.
So this should go it the top front of the valve cover or the back? Really a Breather problem... Would have never thought it.. I will let ya know tomorrow!
JP
<hr style="color: rgb(209, 209, 225);" size="1"> <!-- / icon and title --> <!-- message --> To the "won't rev over 3.5k" owner. Wouldn't be surprised if you had a crankcase ventilation problem.
Recommend switching the PCV valve to a "Breather cap / PCV valve" It's a breather cap (with wire mesh in cap) plus a pcv valve. Available at Autozone. Fits right on the ol' 258.
Mine works great.
Hope this helps.
So this should go it the top front of the valve cover or the back? Really a Breather problem... Would have never thought it.. I will let ya know tomorrow!
JP
83CJ7258greatshape
New member
To azipiper151 - The new breather cap should go on top front of valve cover. Question - do you have oil in air cleaner? If so, definitely switch to the combo breather/pcv cap. I did and have no regrets.
To kidcj82 - I would check to see if coil is getting 12 volts when ignition is in "start". This will take two people. Not sure on specifics, but generally, coil should recieve MAX VOLTAGE when ignition is is "start' as compared to when it is in "run". "Run" involves ballast resistor (or some form of ballast resistor) that extends life of coil. Reason coil receives MAX VOLTAGE in start is to give engine best possible enviroment to start.
Hope this helps
Tom
To kidcj82 - I would check to see if coil is getting 12 volts when ignition is in "start". This will take two people. Not sure on specifics, but generally, coil should recieve MAX VOLTAGE when ignition is is "start' as compared to when it is in "run". "Run" involves ballast resistor (or some form of ballast resistor) that extends life of coil. Reason coil receives MAX VOLTAGE in start is to give engine best possible enviroment to start.
Hope this helps
Tom
defmornahan
New member
Do you mean something like this?
O'Reilly Auto Parts - Results for Shopping Search
I might, maybe, have a similar problem, and I know the PCV valve on my 258 is getting old.
83CJ7258greatshape
New member
That's the part!
iraq_vet_x2
New member
Terry, Finally did the upgrade and it's great. Thanks a lot for the detailed directions.
defmornahan
New member
Wow, where does that go? I looked at it in the store and it is way too big to replace my PCV valve. What do you do with it?
iraq_vet_x2
New member
Terry, I did the upgrade with the E92 coil about a two months ago in my 89 4.2 and its been running great until today. The Jeep died on me while I was on my way back from work. A co-worker and I pulled it back home and I took the multimeter to it. Zero Volts at the pigtail wires with the key off, then 11ish volts with the key on and cranking. I also put my timing light on the wire from the coil to the distro and got no flashes.
Gotta be a bad coil already right?
I put the old coil back on there with the new cap, rotor, wires and plugs gapped at 45 and that didn't work either. Should the old coil have made those plugs fire, or was the gap to much for it to overcome?
Also, is 11ish volts enough to run the coil?
Gotta be a bad coil already right?
I put the old coil back on there with the new cap, rotor, wires and plugs gapped at 45 and that didn't work either. Should the old coil have made those plugs fire, or was the gap to much for it to overcome?
Also, is 11ish volts enough to run the coil?
Last edited:
iraq_vet_x2
New member
All better now. Replaced the Ignition Module and she's alive again.
The tach signal is the POSITIVE, or RED wire terminated on the stock Jeep coil. I just did this to my 258, and I have the Howell TBI setup. One thing to note, at least in my case: When you buy the NAPA ICC1 wire harness for the Ford coil, the colors are reversed. The GREEN wires (2 of them) become the POSITIVE for the coil. The RED WIRE on the stock coil is positive on the Jeep harness
INCORRECT.
The 'Red' wire hooks up to the 'Positive' terminal on the coil,
The 'Green' wire hooks up to the 'Negative' on the coil.
If you look down in the coil connector, next to the terminals, you will see the small '+' and '-' signs next to the terminals.
A Howell TBI injector takes it's signal from either the positive or negative terminal, depending if you have a current triggered or voltage triggered computer for your Throttle Body Injector.
GM used both, and Howell uses both depending on what system/computer you get.
If you reverse the wires to the coil, the spark will jump the WRONG direction in the plug gap, and the gap will be hard to ionize, meaning you will be converting much more of the spark POTENTIAL into voltage rather than having a good, HOT, LONG LASTING spark in the gap.
Keep the polarity correct, and just connect the Howell signal wire to the side of the coil that works for the particular computer you are using.
You SHOULD get a reduced voltage at the ignition coil CONNECTOR (Disconnected from the coil) when the key switch is in the 'Run' position,
And full battery voltage when 'Cranking' the engine.
(Keep in mind that battery voltage will REDUCE as the starter engages and cranks the engine.
If you show 12.6 volts when at rest, then crank the voltage will drop to around 10 or 11 volts, and come back up when you stop cranking,
But it's better than the 4-6 volts the coil gets when the key switch is in the 'Run' position and the resistor is taking a huge bite out of the voltage/current to the coil!)
The starter relay bypasses the resistor to supply more current to the ignition coil during starting so you get faster, cleaner starts,
Then when you let the key switch drop back to 'Run',
The ignition resistor comes back into play to keep the module alive during 'Normal' operations.
When you connect to battery 'Positive' with a test light,
And probe the 'Green' wire terminal on the coil connector,
(Unhooked from ignition coil) you should get a flashing light when cranking the engine.
This means the module is triggering the coil to 'Fire' each cylinder.
Most of the time when you have the ignition switch in the 'Run' position, you will get a steady 'Bright' light when the engine isn't cranking.
This is a quirk of the Jeep/Motorcraft module, and it's why your module will melt down if you leave the key in the 'Run' position for very long without the engine running.
Constant current through coil/module will overheat the switching transistor and the module will fail to function.
This is also a good way to see if your module is getting a good 'Ground' from the distributor housing.
(Coil/Module grounds through the distributor housing)
If you get a 'Dim' light, then the module isn't getting a good ground from the distributor housing, and you would be better off supplying a dedicated ground to the module 'Black' wire that relying on the distributor housing for 'Ground'.
-------------------------------------
With test light connected to 'Ground' or battery negative,
If you get Reduced voltage to the coil terminal in the 'Run' position, that is normal. (Dim Light)
If you get battery voltage to the coil terminal in the 'Crank' or 'Start' position, that is normal. (Brighter light)
That means the 'Issue' isn't the fusible link that feeds the fuse block, the ignition fuse, or wiring to the ignition coil...
--------------------
With test light connected to POSITIVE source,
If you get a 'Steady Bright' light with key switch in the 'Run' position, that is normal.
If you get a 'Flashing Bright' light with the key switch in the cranking position (engine cranking over), that is normal.
If you DO NOT get a steady bright light, that means the ignition module is cooked, or not getting a good 'Ground',
And not having a good ground will cook the ignition module over time.
If you DO NOT get a flashing light with the engine cranking, that means the module isn't switching the coil On/Off to fire it.
That could be anything from power to the module not getting through on the 'Cranking' circuit,
Ground is faulty,
Trigger signal not getting through to the module,
Trigger in distributor has quit working...
Or the wiring between trigger & module is toast.
This would be a good time to disconnect the two wire 'Power' connector from the module and test the harness side.
Harness 'Blue' wire should be 'Hot' when cranking.
Harness 'Red' wire should be 'Hot' when in 'Run' position.
---------------------------------
With just a test light you can locate which side of the fire wall the 'Issue' is, and if it's a module/trigger or power supply issue to the module/coil.
-----------------------------------
One other thing,
The E-core coil is VERY hard on the factory module.
Very common for the factory modules to burn up after switching to E-core coils with I-6 engines!
A MUCH better choice for the I-6 engine with factory DuraSpark module would be the MSD Blaster 2F coil,
p/n 8205.
It is a DIRECT replacment for your factory coil and will keep the module alive, and produces much more spark energy than the factory Jeep/Motorcraft distributor.
The p/n 8205 has the Ford type terminals on top, so you don't even have to change coil connectors, just pop the factory connector right on the MSD 2F coil and go.
An E-core coil is a worth while switch, even if you have to switch ignition modules to run in *IF YOU HAVE A V-8 ENGINE*...
The I-6 engine simply doesn't turn enough RPM or have enough cylinders to require a fast saturating coil like an E-core coil,
And fast saturation on slow firing engine means you are sending too much current to the module, and it overheats...
Stick with the Blaster 2F coil if you have an I-6 engine and things will be MUCH nicer for you in the long run!
Last edited:
This is why I don't normally respond to posts on forums, but no one else seemed to have done so for this person, so I gave it a shot. FIRST of all, I said in MY case all of this is correct. I checked the polarity on the new coil BEFORE I attached the new NAPA wire harness, and that is how I came to the conclusions set forth in my post. I have no idea as to why the wires are backwards color coded on the pigtail that NAPA sold me to go with the coil, and it still makes no sense to me! I also have no idea as to the use of a negative tach signal as used by GM or Howell for a triggering signal, and do not have any idea why they would use both, (I will guess that's application specific, sine the Howell kit is derived from the GM 4.3). I leave that up to engineers, and please take that as a bit of a joke on engineers, as if they are left to themselves, they will come up with a myriad of ways to do one thing!
Anyway, as you stated that they since they use both, I am correct, as I stated in my post, for my application, and not incorrect, as you stated, in your reply.
Now, I will freely admit ignorance in a lot of the how's and why's, especially with fuel injection, as I have only done two of these swaps, and am willing to take in as much information as possible, as to avoid making mistakes in the future, therefore, I have two questions:
One: is the reason for the voltage drain if you connect a coil's wiring backwards, and cause a reverse fire in the plug, due to it grounding itself on the head, at the spark plug threads, and wasting energy? It would seem to me that it would not fire at all.
Two: How in the world does it fire, if the positive energy goes to the grounding electrode on the spark plug?
I see that there is a lot of respect here on this forum for you, and your answers as far as I can tell are well received, but I think that maybe we have gotten off on the wrong foot here, and I really don't want that. I want none of this reply to be taken in mean spirit, as I am sure you didn't in your reply to me, but honestly your reply come off as quite condescending in my eyes, epecially with the capitalized "incorrect" as the start of the reply.
Well wishes,
Glenn
Similar threads
