Join Date: Apr 2017
Saintlouis74 is offline
Weak Spark on Cylinder 4
I have a 1997 S10 with a 2.2 4banger, that i completely rebuilt myself. New main bearings, cam bearings, piston rings, reseated valves, all new gaskets, new coils, plugs and wire, control module, fuel injectors, new air/fuel filters, new fuel pump regulator.. Did a compression test (12 cranks) 149-152 psi through out all cylinders. even switch the ECMout with a different one..
My problem is that Cylinder 4, when i pull the plug off to check the spark, it barely makes it out the boot. and when i disconnect it, theirs no drop in the performance of the engine. 1-3 has a strong spark, and when i pull those off the engine starts to hesitate more.
I switch the ECM with a junkyard one(it fired the car right up but had the same issues) because it threw a ECM replacement code with the ODB scanner
Codes: P0200, P0405
i have no blinking CEL
ive tried tracing the 5v 12V coming from the ECM, when i uplug the EGR connector the 5v and 12v are there, but as soon as i connect it to the EGR it goes away.