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Morning All,
I have a 308 that is on gas. Just fitted a brand new HEI distributer with new coil, plugs and leads.
Would not start. Switched to petrol and started but ran very poorly.
Checked spark and it was yellow and weak.
Can anybody suggest what may be the issue with the weak spark?
Any advice welcome.
cheers Dave
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Two items to check when fitting an HEI dissy to an HQ.
1. Have you bypassed the ballast resistor so that the dissy is receiving a full 12 volts ?
2. Are you using the correct HEI type ignition coil for that dissy ?
Dr Terry |
If at first you don't succeed, just call it Version 1.0 |
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Thanks Dr Terry,
Where would I find the ballast resistor?
This is an R&E distributor for a 308 that came with a coil in the same box, so assumed this was matched to distributor.
One yellow wire coming out of the firewall which was attached to + side of old coil. All replaced in same sequence.
Dropped new dizzy straight in.
Is there a test I can conduct to check for 12v?
Have I missed anything?.
kind regards Dave
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I assume you mean RAE brand, if so then the coil should be correct, but it should also have come with instructions regarding the 12V supply.
The ballast resistor is an inclusive part of the wiring harness & insures that the old coil got only 8V with the engine running. Now that you have fitted a higher current coil using the same supply, you probably now only have 7V (or less) supplying the coil. This is why the spark is weak.
There are various methods of fixing the problem, you could run a new wire or fit a relay etc. The simplest method is to lower the steering column to gain access to the ignition switch & join the pink & yellow wires together. Don't cut any wires, just remove some insulation off each wire & then solder the 2 wires together. This ensures that you now have 12V in both the start & run switch positions. If in doubt get some help.
BTW, the easiest way to see how much voltage you have at the coil now is to use a multi-meter & select DC volts & check at the yellow wire on the coil with the engine running.
Dr Terry |
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Many thanks for your advice Dr Terry.
You are correct, the distributor is an RAE brand.
I will follow your instructions an solder the pink and yellow wires together and report back.
Again, appreciate your advice.
regards Dave.
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I used the relay system. One thing I liked was being able to unplug the relay & pocket it when I was parked.
Poor mans engine imobiliser! |
Attn camry drivers. The accelerator is the skinny pedal on the right. |
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Yeah, I use the relay method as well.
It has the advantage you mentioned, plus it provides maximum possible voltage to the coil & dissy.
You will always lose a little voltage going thru the factory harness & ignition switch etc. etc.
In the above description, I was just trying to keep it simple.
Dr Terry |
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I like the sound of the relay system, and the attendent benefits, ie, security.
Can you explain simply how I wire in the relay to the coil.
regards Dave
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This was on a HQ, was a 202, I threw in a 350. From memory (circa 1996). I ran power to the relay from the main terminal on the starter motor. From there to the HEI.
The "trigger" wire to the relay was the original reistance wire- cut short to the relay on the firewall.
I never checked the voltage on the "trigger" wire,but it was always
enough to keep the relay latched in.
Dr Terry can explain it far more elegantly than I.
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Attn camry drivers. The accelerator is the skinny pedal on the right. |
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That's a pretty good explanation.
Another way to explain relay wiring is to use the DIN pin numbering which goes like this. These numbers will appear on the relay base.
30 > 12V power (from starter or alternator)
87 > +ve coil terminal
85 > earth (to chassis or body panel)
86 > yellow wire (original coil supply)
The voltage at pin 86 will probably be close to 12 volts, because the relay coil doesn't draw much current so the drop across the old ballast resistor will be only small.
Dr Terry |
If at first you don't succeed, just call it Version 1.0 |
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