Not firing on 1 & 5 cyl.

[gpw]

My daughter 96 3l engine is not firing on cyl 1 and 5. I have changed all wiring and plugs and the coil pack. It still is happening.
Could a the CPS sencor be the culprit. Or are both coil packs faulty. Because 1 & 5 are side by side at the top of the pack.
This is dangerous for her. When she pulls out on the highways. The car takes forever to build up speed. She has been nearly runned over a few times.
I really like to fix this. The car has 338,000km on it also.

[65comet]

I would swap them with 2 and 6 and then reset the check engine light. If you still get 1/5 then at least you know it isn't them.

[gpw]

Have done that. Pulled the wires and switched onto other plugs and the wires are firing to other plugs when changed at the coil pack.
Connected to an old spark plug to see if spark. No matter which plug wire we put in one or five there is no spark. This happening on both old and new coil pack.
Is there a possible wire breaker in the system causing this. I cannot see old and new coil packs both defective in the same place.

[shorod]

Since it's both cylinders on a single coil that is having issues, I doubt it's the CMP or CKP sensors. I'd suspect more an issue with the power to the coil or the coil trigger signal/driver. Do you happen to have access to a handheld oscilloscope that you could use to test for coil trigger?

-Rod

[rhandwor]

Originally Posted by gpw

Have done that. Pulled the wires and switched onto other plugs and the wires are firing to other plugs when changed at the coil pack.
Connected to an old spark plug to see if spark. No matter which plug wire we put in one or five there is no spark. This happening on both old and new coil pack.
Is there a possible wire breaker in the system causing this. I cannot see old and new coil packs both defective in the same place.

Check with your parts store and see if you can borrow a noid light. Check if the light is blinking. You can use a gem clip and a 12 volt test light. I think you have a bad connection in the harness.
A bad injector can also cause an idle problem.

[gpw]

I have no Oscilloscope nor do I know what it looks like or to use one. Been told by someone that it is the main computer. I cannot see that. It would cause problems in other areas, would it not. ?
There is no spark at the plugs. Have put a plug in those wires and no spark when the car is running. The plug is grounded to the engine body also. But if I put the wire on another coil plugin, there is spark to that plug.
She can drive the car, just no get up and go.
If there is a problem in the harness where does one start to look. Have to be part contortionist to get at some areas.

[shorod]

The PCM is what provides the trigger pulse to the coil based on input from sensors. Being able to check for trigger at the coil, then at the PCM, would tell you if the PCM is providing trigger but there is a wiring issue to the coil. If there's no trigger from the PCM, then you'd need to confirm if the inputs are good. If the inputs are good, yet no trigger for that single coil, then I'd draw the same conclusion that the PCM is bad. However, Ford PCMs are generally quite robust.

Continuing to drive the car with two cylinders misfiring is just going to cause more issues such as melted and plugged catalytic converters, not to mention the safety concern of not being able to accelerate quickly should the need arise.

In the absence of an oscilloscope you could use a multimeter to check for continuity between the coil trigger pin at the PCM and the connector at the coil.

Do you know which of the 3.0L V6 engines this car has (2V/cyl, FFV, or 24V DOHC)?

-Rod

[rhandwor]

Since both wires are on the same coil. I'm not familiar with this vehicle. A Chevy fires both wires at the same time. One plug is used for a ground. If you have one bad plug or plug wire neither plug fires.
I've had found bad new plug wires and a cracked plug.
Check each plug for cracks and good electrodes. Use an ohm meter and check each wire. They should read around 1/2 scale. If this doesn't work pull the coil and check the plugs for bent or corroded connections. A Chevy sits on a module which you can check with a 12 volt test light.
Some parts stores can also check these for free.

[gpw]

It's just a regular 3.0L 2v V6.

I cannot get to her car for a bit now. We live 20 miles apart and her schedule and mine right now just are not working next few weeks.
Winter is a coming so I need to get it fixed if I can. No heated shop or garage here.

[65comet]

Is that Delisle Mississippi or Saskatchewan? Just asking in case there is someone else on the forum that might be close by you to physically help. Up in Canada I see it is 4 below in Celsius this morning (25F for us State side folks). So yeah, you want to get on it.

[gpw]

Yes it is Saskatchewan. It is -5 c here this morning. I still have winterizing around here to do. Vehicles pretty much done. Yard stuff to do.