2G No spark on 1 and 4 cylinders

[Dustin269]

Ok i know this has been brought up many times but let me explain

I installed a new head gasket and put it all back together and come to find out it was only firing on 2 and 3 so i looked all over the forums and all i could come up with as possible problems was Cam sensor coilpacks and power transist unit

So i replaced the power tr unit and coils and nothing changed still running on 2 and 3 only, later on i realize the cas WAS broken so i replaced that and still nothing here is where my question is its a brand new sensor and when i start the car it runs like crap so i was checking connections and i unplugged the cas and nothing changed what so ever with it unplugged is that normal? or is the sensor bad even though its brand new?

 

[poonman]

1.You need to turn the Key on and check the Voltage to the CAS and Crank Sensors first.

2.Check the Coil again for the proper resistance or let Autozone do it for you.

3.Check for broken Plugs/Wires

 

[Dustin269]

I know the plug wires and coil are good because I flipped the wires on the back of the coils and lost spark on spark on 2-3 but 1-4 were firing

 

[6A12TT-7G]

I'd check the loom, if you've replaced the ptu it's most likely going to be a link between the ecu and ptu or between the ptu and the coilpack that isn't sparking

 

[Dustin269]

i guess thats my next step is the ecu

 

[CharlieGTGSX]

Mine do something like that... Replaced 2 broken cables in the harness between PUT and COILS and done! worked again... Old toasted harness give us some issues...

 

[Uno5887]

one solution i keep running into is recheck your belt timing. people mess up the dowel pins in the cam gears if its out of time youll have issues.

 

[Screemin eagle]

In 26 years of wrenching on dsm’s I’ve never seen a misaligned timing belt knock out 2 cylinders. It’s more than likely ignition

 

[curt-s]

1+4 share a coil and the same igntion pulse due to wasted spark. if you're losing both, it's an ignition component or wiring.