1998 EZ-go Gas with weak spark

[goblerblaster1958]

My 1998 EZ-GO gas cart is getting consistent but very weak spark. Motor will not start. After reading many threads on this site, I replaced the battery terminal connectors, took a grinder and shined up the place where the frame ground connects, and shined up the connectors on the frame ground, and connected it with new bolts. All points were very rusted.

Much to my dismay, everything stayed the same as far as spark is concerned.

I took an Ohm meter and read across the primary leads on the coil... positive to negative and got full peg (infinity)on every scale on the ohm meter. From what I read in the EZ-GO manual- if I understand it correctly- this should not be happening.

My question is , does this indicate a bad coil, pulser, igniter- or am I testing the coil incorrectly? The spark is very small and yellow in color instead of big and blue.

Any suggestions on how to proceed to correct this weak spark condition would be VERY much appreciated !!

[goblerblaster1958]

I have done the 12 volt test light to the negative terminal of the primary side of the coil and the light is flashing when the motor is turning over. I trimmed 1/2 inch off both spark plug wires and reinstalled them. Plugs are still firing , but just not a very good spark. I did the ohm test on the leads from the pulser coil and am only getting 125 ohms. That is not within the scale of 435 to 586 ohms called for in the service manual. I have taken the pulser coil off and plan to replace it.

Does this seem logical since both the plugs are firing? Am I missing something ? I hate to spend the money on a new part if something else could be the problem, but it read the same ohm reading on and off the cart. Also, do you have to pull the gas tank to get the plastic cover off that covers the pulser coil. I got the pulser coil off but not sure I can get it back on to start the bolts without getting the cover off !!

[TomStark]

OK, not very likely to be pickup coil because it is signaling to fire. So it is most likely going to be coil or ignitor. Just guessing, I would guess coil. but without it being here that is just a guess.
Tom

[goblerblaster1958]

Thanks, I don't understand what the pulsar coil does, but it does not test to be in ranger on the ohms scale shown in the service manual. The spark is consistant, but very weak. I was -like you- thinking that if it was firing at the plugs it would not be the pulsar coil....

Anyone else got an opinion on this , please reply ..............

[my1423]

Bad coil or cdi. Most likely a failing coil. Ohm it out unhooked from the cdi which can give similar symptoms.
The pulsors are rarely in spec and they still work. As long as they have a consistent output they trigger the cdi. The cdi and coil produce the spark not the pulsor.

For really hot spark install a caprice c849 hei dual coil 10$ and convert to a 4 pin gm hei ignition module to drive that nasty coil. 10-18$ high performance ones off ebay. Recommend mounting it to a large heatsink. Frame mounted works but if you strive for a large 45-60 plug gap the heat will burn it up.

Top of forum sticky for the 3pg conversion.
This site has some other ideas and diagrams to convert almost anything to hei. Points included.
http://www.geocities.ws/loudgpz/index-2.html#home

[TomStark]

That wide gap will give a hotter spark, but shorter duration. I would never go .060, for our carts .035 is plenty will give WAY hotter spark than stock and plenty long duration too.
Tom

[my1423]

An 89 olds v6 that uses the same c849 coils uses a recommended .60 plug gap.
It uses 3 dual coils.
It does have a different module but it is still based on the same design.

Wider the gap the hotter the spark.
Narrow gap lower temperature.

Hotter spark will ignite a leaner mixture but can be fouled easier.
Hotter can also help burn fouling away after the cylinder is firing.

The real issue is dwell time.
At higher rpm the dwell time drops and a wider gap may not be possible for the power output falls due to lower coil charge times.
This can result in missing at higher rpm.
Early Gm hei v8 4 wire units were known for this above 5000rpm.
This does not apply to our carts at all.
Since we are using a single spark event each revolution vs 4 and we are running a lower gap to be overcome.
In a 4 pin hei v8 distributor not only do you have the 35 - 45 plug gap but also the 20-35 cap rotor gap.

I have seen coil on plug engines that still ran fine but missed at high rpm that had no lower electrode left. Burned away because they had never had the plugs changed. 120 plus plug gap.

[TomStark]

Just worked on an explorer that had 180 k miles on a set of plugs, was not running due to timing chains being bad.
On the pro stock car we ran .020 plug gap, but then we had 15:1 compression, VE over 100% and a 10,200 shift point!
I would never run the .060 gap, even on a motor that called for it, just too much gap, and was done I am sure for emissions. .035 or .040 or even .045 is plenty of gap and gives a longer duration spark than a wider gap.
Tom

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