Replaced injectors now have no spark?

Tiny
BDGOODWIN
  • MEMBER
  • 1997 TOYOTA TACOMA
  • 4 CYL
  • 4WD
  • MANUAL
  • 420,000 MILES
Replaced injectors now have no spark. Had a rough idle for about 3 months but would run ok. Sometimes it would run rough for a few minutes then smooth out. Mine dosent have a distributor just the crank and cam sensors I plan to replace both of them this weekend. My question is does the truck have an ignition control module? I have read online and most say it does but it also think they have a distributor not a wasted spark system.
Thursday, April 9th, 2026 AT 5:45 AM

3 Replies

Tiny
AL514
  • MECHANIC
  • 5,593 POSTS
Hello, you are correct about the 2 coil packs being waste spark system, the igniters are built into each coil, (ill post a diagram showing the inner workings of the coils). But if you had spark prior to the injector replacement, I would retrace your steps in the areas you were working in the truck, check any connectors for loose pins or poor fitment.
And where did the injectors come from? And are the injectors being fired as well?
I will pull up the wiring diagrams so you can check the wiring.
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Thursday, April 9th, 2026 AT 9:37 AM
Tiny
AL514
  • MECHANIC
  • 5,593 POSTS
The first diagram is both coils, diagrams 2, 3(Top & Bottom) are the aftermarket drawings, 4th diagram is the resistance spec for checking the coils, and diagram 5 is the oem wiring for the coils that shows the internal workings of the ECM ignition coil control.
If the new injectors installed were not oem from Toyota, I would be concerned about that as well, we are seeing a rash of bad brand new parts, but if they are not Toyota injectors it can cause any number of issues.
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Thursday, April 9th, 2026 AT 10:22 AM
Tiny
AL514
  • MECHANIC
  • 5,593 POSTS
This is the procedure for checking the Secondary windings of each coil, let us know what you find.
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Thursday, April 9th, 2026 AT 10:27 AM

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