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Intermittent to No spark VS S3 5ltr 304 roller motor


New Member
Jan 7, 2019
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Hunter Valley
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VS Lowndes Tribute
Righto 5ltr guru’s...
I require some assistance in rectifying an intermittent spark issue.
This is a bit of a read but gives you the full context of how I ended up where I am now.
My 5ltr donor Ute (VT Roller motor/sequential injection) had a miss on No#5 but had spark and injection pulse, swapped plugs and no different. Found that the engine had blue top injectors fitted so acquired a set of stock blacktops and reconditioned them. Went to swap them out and found that the injector ports were nearly half blocked by the Valley gaskets so grabbed a new set of gaskets and removed the Inlet Manifold. My theory was that the blue tops (on a stock motor) may have been causing the miss along with the injector port being blocked by the gaskets. Cleaned everything up and went about reinstalling everything after winding the motor over to ensure the valve train looked ok.
Also found that the coil had a decent crack in it (no one has one in stock in my town) and that the dizzy cap and rotor button had been a little munched but chucked them back on to see if the miss was any better after doing the gaskets etc.

Now I have intermittent to NO spark!

Checked injection pulse and it’s fine, checked spark from coil and it’s fine. Thought maybe that the dizzy cap and rotor button may be at fault so just changed them out and initially had spark but it’s once again intermittent at best and for the most part not there at all. Plugs are getting wet so I’m getting fuel from the replacement injectors.

Disconnected igniter (which looks new and there’s a receipt confirming this) and I had no injection pulse so I’m thinking it’s ok?
Also, if the Hall effect sensor is no good then I wouldn’t have injection pulse would I? So I’m thinking it’s ok?

Ideas? Remember that the car was running before I pulled the manifold off, it just ran like ****!

I will order a coil as maybe, just maybe it’s not providing a strong enough spark?




Well-Known Member
Mar 6, 2011
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VS Statesman
What injectors did you use? Vs s3 roller injectors are the same as vs Ecotec injectors. If it has been tuned for blue tops, it won’t run well with different injectors.

Ignition issues are more than likely the ignition module or coil, and in your case I’d say the module is the cause. If it’s a cheap aftermarket one, that’s very likely to be your problem. Genuine is the only way to go with these.