Jacob's ignition systems are crap! Don't wasrte your $ dealing with them. I've had their system 2 yrs and in that time I have had to replace 2 coil wires, one coil, the ICM went out with less than 800 miles on it and now the next box is trash with an internal short, which they won't repair or deal with because it is out of warranty. Since I put this "bulletproof" system in the truck has spent more time down or running poorly that before.

Now that that is out of the way, here is the problem. I now have a 78' dist with magnetic pickups and no box to run off it. I won't give jacobs any more $ and can't afford a toyota or an MSD box. Are there any gm straight 6's with an external ICM that I can wire into my dist? Will the ICM from a V8 work or are they cylinder # specific. I have noticed that on my project 40 with the 318 and electronic igniton that the dist looks identical to the 78' toy dist and there are two wires coming off the magnetic pickup, same colors, etc. If the # of cylinders doesn't matter and the gap between the magnet and trigger are the same or close, would it be possible just to wire in a mopar box (lifetime warranty on box at $20 and resistor at $1.50, much more in my price range)?

Any ideas or suggestions would be greatly appreciated.

And yes, I did the search. Nothing other than the internal HEI conversion or toyota conversions found.

thanks
tom

I run a Hyfire ECM in my cruiser. Been in there for around 10 years now. Works great. If it ever dies I am going to put a MSD in though. For $115 you can't go wrong...

I have not heard of Hyfire. Who supplies them? Is the $115 for the Hyfire or the MSD? The cheapest I've found the MSD is $135.

Why would you go to the MSD? It only has a 30 day warranty, which scares me. Does it have a better record than others?

Thanks for the input.
tom

Mallory makes the hyfire.

And if you look around hard enough for a sale you can find the MSD6A for $120 or so.. Or you can spend $150 on it.

I have been happy with the hyfire but I just think the MSD is a better unit. I think it burns hotter.. Mostly a seat of the pants feeling more than anything else..

Not true. What kind of Junk wires are you running?
The jacobs units put out more juice than most wires will/can handle!I have the ultra wires and they work fine!
Upgrade to better wires.
http://www.jacobselectronics.com/products/sparkplugs/sparkplug.htm
Mike :fj: :jeep2:

Originally posted by FJ40_1969
Not true. What kind of Junk wires are you running?
The jacobs units put out more juice than most wires will/can handle!I have the ultra wires and they work fine!
Upgrade to better wires.
http://www.jacobselectronics.com/products/sparkplugs/sparkplug.htm
Mike :fj: :jeep2:

Okay, what is not true???
Who are you asking questions to. TRW seems to be having some problems with coil wires but them lots of problems with coils and the ecu.
I was just giving on opinion on what I have run.

I bought the whole Ultra Team kit, new spark plug wires, new coil wire, new coil and ICM all from jacobs, all in the lovely blue they use and all crap. I have been dealing with them constantly with this kit since I bought it. I even asked them , while it was still in warranty, if it was suppose to be drawing current from the battery when the key is off. the tech guy said yes and I (admittedly niave to the system) believed him and started a year search for a bad ground that didn't exist outside of the box. I am not the only one to give up on jacobs after repeated junk being sent by them to replace the initial junk. I was warned away from the system from 3 different individuals on another LC board, but didn't listen because my brother was so impressed with his three month old system in his truck. Of course, his box went out one week to the day after his warranty expired. He now runs MSD and is equally as happy as the short period of time the jacob's functioned properly. The system is too $ just to get a year out of.

tom

The 83-86 Stock Toyota Distributor that I used in my Pig works great. Waterproof, fits right in, no problemo. I figure it had been well "burned-in" by the time I got it and it hasn't given me a bit of trouble in 20K+ miles and 2 years.

If you search this board or Woody's you will probably find minwe or someone elses write up about the How-To

trw,

Check out some of the previous threads, like this one on igniters (http://www.pirate4x4.com/forum/showthread.php?threadid=25847) good information.

The only "trick" to dropping in a GM HEI is to swap the distributor drive gear to its TOYOTA part to keep everything happy.

On the GM ignition modules, I prefer the more expensive "made in USA" modules, but either way be sure to use a good heat sink compound (You need just a little, so a electronic shop is a good source for "Pentium Processor Heat Sink Compound" Ya, $5 but a tiny :rainbow: amount).

If you need a little aluminum mount for that GM Module, just drop a line and I'll make you one for $10 (money gets donated to American Cancer Society... )

Just want to make sure you're working on a CARB'd engine. For the EFI stuff you need to use a different GM module.

Jacobs does a great job of Marketing, not engineering. :mad2:

Tom :usa:

Thanks for the advise all. Before I give up on the dist I have now, I am going to use the parts off the 318 ignition and see if I can't make something up myself. I'll let you know if it works. If it does I'll make up a tech write-up and post some pics.
thanks
tom

Roundrocktom,

Thanks for the link. That sounds like a good idea, but I have a few ?'s. The write-ups talk about the conversion in trucks with existing electronic ignition. All I have now is a coil, coil and spark plug wires (all from the Jacobs remains with lifetime warranty), and a rebuilt 78' LC dist with magnetic pick-ups. So from what I can tell the only wires I have to fit the conversion is the two wires from the dist pick-up.

What else do I need to finish the conversion? Does the GM use an external resistor that I would need to get? Has anyone made this conversion on a truck that previously had a points setup?

thanks
tom

Originally posted by trw

What else do I need to finish the conversion? Does the GM use an external resistor that I would need to get? Has anyone made this conversion on a truck that previously had a points setup?

thanks
tom

trw,

Ballast resistor is not required, as the GM ignition module will limit the current to prevent saturating the ignition coil. So I suspect your Jacobs coil, as any ELECTRONIC IGNITION coil from the cruiser should be fine. The early, points only, ignition coils were designed for a max of 4 amps of so (hence an external ballast reistor), but the GM Module will allow more current than that (perhaps up to 8 Amps) leading to excessive heat, shortning the life of the ignition coil. [For the EE's on the list, yes it would also lead to saturating the coil, and a larger back emf pulse to whack away at the ignition module's output stage.... I'm just ignoring that to keep the discussion simple]

The OEM '78 toyota distributor's pickup should work fine to trigger the GM unit. A simple VOM meter can be used to check the pickup coil.

Check that you have voltage to the coil & ignition module in both "start" and "run" positions.

The base of the GM Module is for disappating heat & needs a good "ground" connection... don't try to test it with the module hanging in the air! :D


Tom :usa:

I started having problems with my jacobs after 2 years. I was running one in my '98 GMC Sierra SLT with the Vortec V8 5.7l. It ran strong but everytime I needed extra umph towing a trailer or what not I would start getting misfire messages from my OBC. Then after awhile the truck would just cut out while doing 75mph! I called them and they said that their ignition must be too powerfull for my stock coil. Fine but no - one makes a aftermarket coil yet for the 98 and up Vortec's. Mallory has one coming out but not yet. So I bought another coil and still the same problems. So I tried new plugs and wires, that worked for a while but then it would still cut out in traffic. Fianlly I disconnected the whole mess and have had no more problems. I wouldn't say their stuff is crap cause it worked great for over 2 years, I just think they have some design problems and their customer support doesn't know a damn thing about the product they sell except for spouting numbers that they have on print in front of them.

I hooked up the module as stated on a conversion tech article. 12V run from the ignition switch to the + side of the coil and to the B terminal on the module. Ran a line from the C terminal to the - side of the coil. Hooked up the magnetic pick-up, white to the W terminal and red to the G terminal. I also hooked up the 12V lead coming from the starter solenoid to the + side of the coil. Checking things with a volt meter, I have 12V to the + side of the coil and the b terminal of the module with the key in run possition, nothing in the off possition. I am getting no spark. I checked the magnetic pick-up leads at the module and the is no power at anytime, not with the key in the run possition or with the motor turning over. It is a fairly new dist and pick-up and was working with the jacobs. I checked the jacobs and the two leads coming from the box to the to the magnetic pick-up are putting out about 5-6 volts each. Is the hei ignition module suppose to be putting power to the pick-up? This is a brand new module from the local parts store. What is going on?

thanks
tom

forgot to mention that it is screwed down and has a good, grounded connection.

Originally posted by trw
I also hooked up the 12V lead coming from the starter solenoid to the + side of the coil.
tom

Tom,

Everything sounded fine, but I would NOT hook the lead from the starter solenoid to the coil. Just the ONE lead from the ignition (powered up when the ignition switch is on... confirm it is also powered up when you switch over to "start".)

Do you have access to a ohm meter?

Worth while to unplug the pickup coil leads, you should measure about 200 Ohms coil resistance. (anything between 100 to 300 is normal, usually I'm looking to see if it is an open).

Also check the ignition coil (leads disconnected). I would expect to see the main coil (+ to -) around 1 Ohm (hard to measure on a cheap meter, but a very small resistance). From the tower to (-) around 10K ohms. Once again, don't sweat the exact value but just to give you an idea.

Did you hook up the yellow wire? That is the one to use with 1K ohm resistor inline. It's a tachometer signal: so it shouldn't be required on the FJ40.

Sorry I don't have more idea's for ya... but should give you a few things to check out.

Tom :usa:

This months petersons has a DUI electronic install tech.

Thanks roundrocktom, I really appreciate the continued support. I'll check those resistances tonight. I have a feeling the problem is that the two pick-ups have different properties. I know with the chrystler system there is only suppose to be a gap of .008 between the magnet and the fin and there is no power from the module going to the pick-up. However, on the toyota, the gap is substantially larger, about 1/8th of an inch or more, and there is power from the module to the pick-up. I might be able to use it yet by supplying power to the pick-up. If it doesn't work I'll probably end up trying to use a newer model toyota module or just switching to the gm dist. Both are readily available at my local pick-n-pull.

thanks again for the help
tom

You're welcome.

I'm starting to loose my mind! OK, I already lost it.... :D

Could you check to see if there is a nice magnetic field near that pickup coil? A small screw driver will work, just touch it near the pickup to "feel" how strong that magnet is.

The pickup coil has three parts: The coil itself (nothing more than a bobbin of wire), a magnet, and a distributor rotor to trigger an inductive pulse when the trigger passes a reference point.

For adjusting the gap you'll notice you need a brass feeler guage. I would try adjusting the gap much closer to give a better inductive voltage signal to the GM module. Strength of the magnet does play a role in this, too.

Yes, for some modules they will bias the magnetic pickup coil. Basically a small voltage can be created by using two resistors connected in series from +12V to Ground. Mid point of the resistors provides a voltage signal to the pickup coil. Two 1K resistors will do the trick, but I haven't had to use this for the GM module in the past (I suspect due to luck in having a distributor with a good magnet more than anything else!). This may explain why you see the voltage from the Jacobs unit. I did this trick of resistors to get stock ignition points to trigger a GM unit. Remember the "opening" vs. "closing" condition of the points. For a stock coil, triggered by points, the coil "fires" when the points open.... for the electronic ignition the coil fired when the points CLOSED. Had to mess with a distributor to get everything set up... ended up using a MSD igntiion system! :D

FYI to the Engineers out there... on the "C" side of the module, that connects to "-" on the coil. which is grounded and opened to trigger the coil... ahem, you can get up to a nice 400V pulse. My FET probe for the scope was good for up to 200V.... :emb4: This is also why a 1K resistor inline with a TACH signal is a good idea to prevent damaging the tach! Opps.

Tom :usa:

Thanks again for the info.
I'll give it a go tonight and let you know the outcome Monday.
tom

It seems the dist is not sending the signal to fire to the box. The pk-up has a resistance of 150 ohms. The magnet seems to be strong. If the center of the dist, the fins, are suppose to be magnetic, there is the problem. I thought the fins were suppose to have some magnetic strength. Is this right? Mine don't. Is there a way to re-magnetize them? All the other aspects of the conversion seem fine and everything checks out with the proper resistance.

Thanks
tom

Originally posted by trw
It seems the dist is not sending the signal to fire to the box. The pk-up has a resistance of 150 ohms. The magnet seems to be strong. If the center of the dist, the fins, are suppose to be magnetic, there is the problem. I thought the fins were suppose to have some magnetic strength. Is this right? Mine don't. Is there a way to re-magnetize them? All the other aspects of the conversion seem fine and everything checks out with the proper resistance.

Thanks
tom


Odd! Sounds like everything is fine, yet no signal?

Fins are steel... which will help pass the magnetic field lines through the coil when the distributor's rotor passes around (the fins should line up with two of the rotors "teeth").

Do you have a decent VOM? i.e. a good Fluke ($80+) voltmeter, versus a $5 radio shack special? Check the AC signal when you crank the engine. (Cheap meters are OK for the trail, but I hate finding out the problem was a meter that lied to me... had one that would read low voltages, until the dial was moved back and forth a few times. Tossed it into the trash, and it never bothered me again. Fluke 73 is fine for most of our stuff)

If the ignition pickup hooked up to just the Voltmeter, you should be able to crank the engine over and see about 500mV AC on the reading. Only thought is the air gap (gap it down close as possible).

Sanity Check:

You should have five connections:
B +12V (black w/yellow strip is commonly found)
C "-" of ignition coil
W pink lead from pickup coil
G white lead from pickup coil
GOUND -- back of ignition module connected to a good
electrical ground.

Note, color is from memory... I'm getting old and mixing things up, going from memory. I might have W & G mixed up... basically the pickup coil could have a different polarity based on N-S orientation of the magnet. GM likes one way, My old Heep was another. Doesn't really matter if you have enough adjustment room on the distributor.

There might be another lead from the "-" of the coil, for the tach. Later cruisers all so have that #$%! emission computer, which I thought also used a tach signal. They are funny items, as they do control a few things to drive you crazy when they fail.

This is going on a 1970 FJ40 with a F or 2F, correct? Shouldn't make a difference... just those "emission computer" boxes didn't appear until 1976 or ????

On the resistance check... repeat again and see if the coil is connected to ground on one side.

Just as a sanity check... do you have one of those "test spark plugs" that have a clamp on them? You could hook everything up, and use a 1.5V battery (+ to W, - to G) see if the module & coil are alive. For that matter you could use a tail/stop light wired up to replace the "coil" to see the light turning on and off to make sure the ignition module handles the 3Amps OK. Just trying to make sure you didn't get a bad ignition module (rare, but does happen) and start pulling your hair out trying to figure this out.

Nice thing... after all this, you will know the details of your ignition system very well when out on a trail! :D

Tom :usa:

I have all the connections just as you wrote. I ran a new wire from the run position on the ignition switch to the + side of the coil, then a lead from the + side of the coil to the B terminal on the module. I have a lead from the C term to the - side of the coil. I have the red wire from the pick-up going to the W terminal and the white wire from the pick-up going to the G terminal. I have an old volt meter that seems to be accurate and I am borrowing a newer unit from an electronics lab that works with high $ equipment, so hopefully it is not the meter. (Although I've learned to never rule anything out) I don't have a brass feeler guage, but I have a metal one that I used to "eye" the distance down to much closer to .008 than before. I didn't use it or touch the two sides. With everything connected as above, I checked the voltage going to the w and g terms, nothing, the voltage at the c and b terms, 12v. This was the same with the key in the run position and with the engine turning over, no change. I added the 6 volt leads to the w and g terminals, and repeated the test above. Still had a constant 12v at c and b both in run and with the engine turning over. I was thinking that it was possible a bad module, but since I am seeing nothing at the w and g terms I figured it probably wasn't.
You pointed out an error I was making. I was reading from the pick-up using DC. I will recheck it with the AC mode. I'll try the battery test to check the module.
Can you tell me what voltage or current is needed to trigger a spark from the module? What should I see from the magnetic pick-up leads when the engine is turning over?

Please accept my eternal gratitude for the continued support and advice. Yes, I should know it all inside and out once this is resolved. In fact, even though it has been as of yet unsuccessful, this has pushed my decision to make my own wiring harness and updated fuse block instead of buying a kit.

tom

After reading again, I see I should expect 500mV AC. Yes, it is a 1970 FJ40 with the original F motor. It has about 180,000 miles on it but after the top end was redone has even compressions around 140. I don't have a tach to worry about at the moment, but will log in the resister note for the time that edition finally comes.
tom

There might be another lead from the "-" of the coil, for the tach. Later cruisers all so have that #$%! emission computer, which I thought also used a tach signal. They are funny items, as they do control a few things to drive you crazy when they fail.

I bet this may be the problem with my '76 FJ55 Calif. version. My VSV is not working and when I swapped in the new distributor I removed all wires but one.

Any idea which color of wire gets hooked up?

Hew TRW - What's the status? :mad: or :beer: ???

Screwzer - Man, did you get me going on the Emission Control Computer used on FJ40, FJ55, FJ60.... Here's what I dug up:

Emission Control Computer
'79 FJ40 FJ55
_____
/ |
START 2 1 IGNITION Coil +
IGNITION COIL - 4 3 Thermo Sensor
IGNITION 6 5 Thermo Sensor
xxx 7 GROUND
Vacuum Switch 8 9 VSV for AI
10 11
Fuel Cut Solenoid 12 13
\_______|



'81-'87 FJ60
_____
/ |
START 2 1
IGNITION COIL - 4 3 Thermo Sensor
IGNITION 6 5 Thermo Sensor
xxx 7 GROUND
Vacuum Switch 8 9 VSV for AI #1
VSV for AI #2 10 11
Fuel Cut Solenoid 12 13 Speed Sensor
\_______|


Posting will wipe out the spaces, basically you can find the numbers 1-13 to correspond to the connections. Still I'll leave this for a future reference. Most rigs have been "desmogged" but lots of folks overlook the Emission Computer, and also fail to realize they are running too much ignition advance with the EGR disconnected.

NOTES:
Vacuum Switch: No Vacuum: NO continuity
Apply Vacuum: It grounds to the sensor body

For the '79 FJ40, the computer shows a diode used between pin 2 (start) to pin 1(Coil +), which is reasonable to bypass the ballast resistor when starting.

On the FJ60's, A speed sensor is added, as an additional VSV AI (Vacuum Switch Valve, Air Injection) valve.


Deceleration Fuel Cut System:
Under high vacuum conditions and HIGH (above 1800 rpm) rpm the fuel cut off is turned off (cutting the slow circuit in the carb).

Distributor:
1. Vacuum Line closest to distributor body: Hooked up to ported vacuum source (i.e. no vacuum at idle, lots of vacuum at partial throttle cruising, no or little vacuum at WOT -wide open throttle).
2. Vacuum Line further way from body: HAC (High Altitude Compensation). This allows about an extra 5 degrees of advance for high altitude (above 4,000 ft) conditions, improving driveability.

On the FJ60 Emission Manual (2F Emission '81), some of the diagrams clearly show a switch controlled by engine rpm, including AI VSV's, yet the only diagram giving rpm values in the Deceleration Fuel Cut System. :confused:

I love the test procedure for the speed sensor "jack up ONE rear wheel.... ". Don't try that at home kids! :D

So it looks like you need that TACH SIGNAL (Coil "-") hooked up for everything in the emission group to work.

Time for :beer:

Tom :usa:

Unfortunately we have had some pretty crumy weather down here the past couple of days. I am about half way through the construction of my new garage (always takes much longer than anticipated when doing it yourself) so the 40 is out in the drive. The constant rain has not provided the best environment for outdoor electronics. It is suppose to be ending today and reaching the 70's this afternoon, so hopefully I will be able to check it out tonight and let you know tomorrow. Commuting in this weather the past two days on a motorcycle has definitely spurred the need for this project to a timely end. I'm getting too old for rain gear.

tom

Thanx roundrocktom
I owe you a :beer:
I'm gonna delegate this project to my gunner on the trip who's an electronics engineer. He's gotta work for his seat somehow
:D .


Thanx again

Turns out the brand new module from Autozone was bad. Took it back there this morning, after it failed to light the bulb with a batery, and had it tested. The guy couldn't believe it was bad and tested it about 20 times before finally agreeing that it was in fact bad. Got a new one and tested it before I left, works fine. Will throw it in tonight and hope for spark.
tom