Ignition problem???

[dodgeelder13]

Hi I’m 17 and building a 90 d150 with a 318 magnum carb swaped. I’m having an issue with my ignition box I believe. Truck starts and runs for a little bit runs great then missfires and dies (can start right back up and runs fine then repeats). I was having a high rpm breakup also but I bypassed the ballast resistor and it seemed to help. Idk if it matters but I’m running an orange box and a blaster 2 coil. only getting 3.5v at the coil when testing with coil ground and 13v if I check with a body ground. I thought it was the carb but I’ve tryed my buddy’s known good carb and it still did the same thing

 

[Professor Fate]

DO NOT bypass the ballast resistor with a factory style electronic ignition. You'll cook your ECU. Probably what you're experiencing. It is designed to run at reduced voltage, it only gets full voltage when starting.
As far as your high speed misfire, make sure your coil is one meant to be used with a ballast resistor. There is a difference.

 

[67Dart273]

Hi I’m 17 and building a 90 d150 with a 318 magnum carb swaped. I’m having an issue with my ignition box I believe. Truck starts and runs for a little bit runs great then missfires and dies (can start right back up and runs fine then repeats). I was having a high rpm breakup also but I bypassed the ballast resistor and it seemed to help. Idk if it matters but I’m running an orange box and a blaster 2 coil. only getting 3.5v at the coil when testing with coil ground and 13v if I check with a body ground. I thought it was the carb but I’ve tryed my buddy’s known good carb and it still did the same thing

You are going to have to explain exactly your testing connections and conditions.

If you bypass the resistor (and as mentioned, you should NOT) then with the meter connected from coil + to ENGINE BLOCK or BODY and with the key in RUN but with engine stopped you should get "same as" battery voltage, AKA fully charged battery, about 12.6V

With engine running, and same connections, you would get the charging system running voltage, which is going to depend on condition of charging system, loads turned on, (headlights, etc) and engine RPM

What you SHOULD get with a normal, normally connected system, ............and with a proper ballast

1....Meter from coil + to block, key in "run", engine stopped. Should get somewhere between 6 and 10V. This shows the coil is drawing current through the box, and the resistor is dropping the coil voltage.

2....Meter as above, read meter while cranking WITH THE KEY. Should get "same as battery" and battery will be drawn down some with starter. Should see minimum of 10.5V or higher

3....Coil NEG to block, key in run. Anywhere from 1/2--1V or a bit more. This is the box grounding the coil NEG, but that goes through a transistor and circuitry so there is some voltage drop.

===========================

For "becuz," unbolt the box, scrape around the bolt holes and remount using star lock washers. Box MUST be grounded.

"Work" all connectors in/ out several times to check for tightness and scrub the terminals. ECU connector, ballast connectors, and distributor pickup ESPECIALLY

"Wiggle" test harness in various places with engine running, INCLUDING the ignition switch (key)

 

[dodgeelder13]

You are going to have to explain exactly your testing connections and conditions.

If you bypass the resistor (and as mentioned, you should NOT) then with the meter connected from coil + to ENGINE BLOCK or BODY and with the key in RUN but with engine stopped you should get "same as" battery voltage, AKA fully charged battery, about 12.6V

With engine running, and same connections, you would get the charging system running voltage, which is going to depend on condition of charging system, loads turned on, (headlights, etc) and engine RPM

What you SHOULD get with a normal, normally connected system, ............and with a proper ballast

1....Meter from coil + to block, key in "run", engine stopped. Should get somewhere between 6 and 10V. This shows the coil is drawing current through the box, and the resistor is dropping the coil voltage.

2....Meter as above, read meter while cranking WITH THE KEY. Should get "same as battery" and battery will be drawn down some with starter. Should see minimum of 10.5V or higher

3....Coil NEG to block, key in run. Anywhere from 1/2--1V or a bit more. This is the box grounding the coil NEG, but that goes through a transistor and circuitry so there is some voltage drop.

===========================

For "becuz," unbolt the box, scrape around the bolt holes and remount using star lock washers. Box MUST be grounded.

"Work" all connectors in/ out several times to check for tightness and scrub the terminals. ECU connector, ballast connectors, and distributor pickup ESPECIALLY

"Wiggle" test harness in various places with engine running, INCLUDING the ignition switch (key)

I have a 4 pin box do I need to get a 2 or a 4 spade resistor? And I think it’s wired wrong I had the resistor before coil and full 12v to ecu box. And thank you for the information I will check it out tomorrow

 

[CFD244]

Following.

 

[Professor Fate]

I have a 4 pin box do I need to get a 2 or a 4 spade resistor? And I think it’s wired wrong I had the resistor before coil and full 12v to ecu box. And thank you for the information I will check it out tomorrow

A four pin box uses a single resistor. A five pin box uses a double resistor. You can use a four pin box in a system wired with a double resistor, but not a five pin box with a single resistor. Fun, huh?
Sounds to me like you've got major wiring issues.
A '90 D150 (V8) would have had a TBI system using a PCM. The PCM also handled the charging system, and if you've eliminated all that, you've got a whole snake's nest of wires to sort through to find the pertinent ones to make your systems functional- both the ignition and the charging system. It also had rudimentary transmission controls to control the O/D and torque convertor lockup, if so equipped.
Ideally, you need to get a factory service manual; or at a minimum, get copies of the wiring diagrams- and then settle in for some investigative reading. You may also need to figure out how to wire your gauges so they work without the computer sending them signals.
But to give you a basic rundown, you need two wires for your ignition:
A "key on" (run) hot feed.
A lead that is hot only when the key is in the "start" position. This can not be the same wire that
activates the starter relay.
This is a basic layout of how the system gets wired, including the charging system with alternator and new electronic voltage regulator:

 

[dodgeelder13]

Ba

A four pin box uses a single resistor. A five pin box uses a double resistor. You can use a four pin box in a system wired with a double resistor, but not a five pin box with a single resistor. Fun, huh?
Sounds to me like you've got major wiring issues.
A '90 D150 (V8) would have had a TBI system using a PCM. The PCM also handled the charging system, and if you've eliminated all that, you've got a whole snake's nest of wires to sort through to find the pertinent ones to make your systems functional- both the ignition and the charging system. It also had rudimentary transmission controls to control the O/D and torque convertor lockup, if so equipped.
Ideally, you need to get a factory service manual; or at a minimum, get copies of the wiring diagrams- and then settle in for some investigative reading. You may also need to figure out how to wire your gauges so they work without the computer sending them signals.
But to give you a basic rundown, you need two wires for your ignition:
A "key on" (run) hot feed.
A lead that is hot only when the key is in the "start" position. This can not be the same wire that
activates the starter relay.
This is a basic layout of how the system gets wired, including the charging system with alternator and new electronic voltage regulator:
View attachment 1716147468

Based off that diagram it’s wired correctly. So I got the truck from a crackhead for 500$ already with the 318 magnum in it and 46re the swap was done horrible, there was the 90 wiring harness and the 02 van harness ziptied up and ecu flopping around found house wiring and wire nuts in it so I completely stripped everything but the dash wiring. Now I have a fuse box under the hood and everything is fused and relayed and to control the trans I have a firepunk anteater. I think I had the wrong ballast resistor (1.6ohm) and I think I fried the ecu when I bypassed the resistor causing my issues. I have a msd blaster 2 coil should I run there .8ohm resistor?

 

[67Dart273]

I have a 4 pin box do I need to get a 2 or a 4 spade resistor? And I think it’s wired wrong I had the resistor before coil and full 12v to ecu box. And thank you for the information I will check it out tomorrow

No you WANT 12V to the ECU with key in the run position. You only NEED a 2 pin resistor with 4 pin box but if you use a 4 pin resistor, the other side is simply not used. Also you cannot tell a used/ unknown box 4 pin from 5 pin if it has 5 pins. Some boxes were made with 4 physical pins, others with 5.

 

[Dana67Dart]

FYI on either the 4 pin (single ballast) or 5 pin (double ballast) the ballast protects the coil. On a 5 pin the second part also reduces voltage to the ECU.

 

[TrailBeast]

So the spark goes out and it dies?
Or does it continue to spark until the engine stops turning?

Just because we are talking about an ignition issue, doesn’t necessarily mean it is.

 

[halifaxhops]

sounds like another new orange box going out when t gets hot. Have a pic of the ecu? The new ones have a fake transistor and the one it uses is buried in the potting and overheats. Pretty common.

 

[AJ/FormS]

In my testing, what I have found is;
If you have a fully functional factor Dual-Ballast ignition system wired like it was a 71 Duster, running a 5-pin ECU, then;
1) it will run with any factory ECU off any SBM or slanty car; at least all the ones in my collection of about a dozen did. and
2) it will also run any 4-pin ECU; the ECU side of the Dual ballast just "deadheads" at the empty socket ......... which means you always have a spare on board, lol..
3) On the few 5-pin ECUs I tested; they all ran on battery voltage for extended periods of time,
4) the 4-pin ECU Orange box I ran, would start to malfunction at over 18 or so volts, and under about 7 volts. Between 8 and 18 it seemed to run fine on my car. But I noticed no particular performance change in that 8>18 voltage range.
5) After my Orange box eventually quit, I changed my Amp to what is now, an old Jacob's Ignition, dash-mounted, dial-back unit, and
to a square-top, Accel Super-Coil, which, 22 years later, both of them are together, and still working fine,
6) I recommend NOT to try and run an E-core compatible coil, on the factory style NOT CDI, amp. Most of those coils need a Capacitor Discharge of 525 volts, and do not do well on 8volts continuously switched.

 

[MadScientistMat]

Just to confirm - you've swapped to the earlier distributor, right? A Magnum distributor is a single tooth cam sync and won't work with an earlier ignition module.

 

[67Dart273]

2) it will also run any 4-pin ECU; the ECU side of the Dual ballast just "deadheads" at the empty socket ......... which means you always have a spare on board, lol..

4) the 4-pin ECU Orange box I ran, would start to malfunction
5) After my Orange box eventually quit,

I little of this may be misleading.

I guess you were joking, but the 4 pin ballast does not give you a "spare."

You cannot really (none of us) any longer make general statements about "orange" boxes, or any other kind simply because the market (A VERY LONG TIME AGO) became so polluted with knock-offs and fakes, that "who knows" what is really an orange, a chrome, or a gold box anymore. I REALIZE there are ORIGINAL ones, but many who "come along" may not know that. I've got several "chrome" (chromed) boxes. Every one of them is an import junk late model with the infamous fake transistor. (The operational transistor is buried inside the box)

Again, what I'm saying is, YOU may have an orange box, but whatever someone else has might be orange "in color" only

 

[dodgeelder13]

Borrowed an ecu from a buddy and got a .8ohm ballast resistor and truck runs mint now. What would be the best replacement ecu? I don’t want to go back with a eBay special or a parts store ecu. I’ve looked into the four seconds flat adjustable rev limit ecu but that’s out of my price range. Again thanks for all the help

 

[CFD244]

I understand that the Hi Rev 7500 by Rick Ehrenberg is a good unit. I have one for my car but haven't run it to confirm. I think his handle is "Rick's Mopars" on Ebay. Hopefully someone will chime in with some real world experience with one. There are some write-ups on it on other sites.

 

[AJ/FormS]

I guess you were joking, but the 4 pin ballast does not give you a "spare."

What I mean is this;
if you are running a 4-pin Ecu in a Dual-ballast circuit, the one ballast is in series with the coil, and the other "dead-heads" at the non-existent 5th pin.
If your Ignition craps out and you trace it to a faulty ballast, you just transfer your coil wiring to the other ballast, which, until now, it hasn't been doing anything. In other words, it has been your back-up/spare. It doesn't matter what the ohm reading difference is, it will save you a tow-truck ride home.
And no, I am not running an Orange box, I learned my lesson a long time ago.

 

[RustyRatRod]

I understand that the Hi Rev 7500 by Rick Ehrenberg is a good unit. I have one for my car but haven't run it to confirm. I think his handle is "Rick's Mopars" on Ebay. Hopefully someone will chime in with some real world experience with one. There are some write-ups on it on other sites.

View attachment 1716148164

Yup that's a good one. I run one on Vixen and have a couple of extras. Jegs also sells them as well as Amazon. They are advertised to be made in USA.

 

[halifaxhops]

If I was going to buy a new one that is the one to go to. From all my testing never had one fail and it is actually good to 7500 RPM also. Hell the price is great also.

 

[4spdragtop]

Troy do you know if the Hirev is suitable for lower rpm range? Or is it "race only"??

I understand that the Hi Rev 7500 by Rick Ehrenberg is a good unit. I have one for my car but haven't run it to confirm. I think his handle is "Rick's Mopars" on Ebay. Hopefully someone will chime in with some real world experience with one. There are some write-ups on it on other sites.

View attachment 1716148164

 

[CFD244]

Troy do you know if the Hirev is suitable for lower rpm range? Or is it "race only"??

You know, I never asked that. I bought the distributor (supposed to be spec'ed like the Mopar performance units) and electronic conversion kit from Rick.

 

[halifaxhops]

Troy do you know if the Hirev is suitable for lower rpm range? Or is it "race only"??

Steve it is good up to 7500. No issues ay=t all lower rpm.

 

[CFD244]

You know, I never asked that. I bought the distributor (supposed to be spec'ed like the Mopar performance units) and electronic conversion kit from Rick.

I messaged Rick today regarding the Hi Rev 7500 ECU and I quote................

"Long duration idling isn't certainly not good for the cam and lifters, but my ECU is perfectly happy!"
Rick​