Only running on 2 cylinders

[lofreqq]

The car is at the mechanics and he called me today and he said he is only getting spark from half of the coil. He tried a new coil and got the same results...

He said that he believes that the ECM is bad and not sending signal to fire.

Does this sound correct or does anyone have anythiing different to check ?


Thanks!

 

[goldbomb79]

Did he check the cas to see if it's good?

 

[muleunit]

Take out your ecu and check the capacitors inside, the ecu is right behind the radio. Look for leaking/bulging.

nevermind I didnt see that it was a non turbo.

 

[lofreqq]

Did he check the cas to see if it's good?

cas ? He mentioned changing the cam position sensor and he also asked me about the crank position sensor. The crank sensor is a newer model from a 98 which has a different plug. I was told to just wire in the pigtail on the crank sensor from a donor harness and it would work fine. Does this sound logical ?

Thanks for the help !

 

[goldbomb79]

cas= cam angle sensor or crank angle sensor I'm not sure if that would work or not. Have you driven the car since you put that crank sensor on there, or has this problem started since then?

 

[burkgonzo]

Whats a cylander?

 

[lofreqq]

Whats a cylander?

Do i get extra points for spelling ?

Well , the motor that was in there had a bad knock. It ran ok but had the knock. I drove it home,about 5 miles , to put the new motor in and it started running like it was missing really bad. The new motor sounds the same.

All of the sensors on the new motor are from the old motor except for the crank position sensor. The car is a 95 and the new motor is a 98 so all the sensor plugs are different.

So basically all the sensors were transferred over except the crank position sensor.

 

[Doug Mercer]

wires, plugs, coil, fuses. check em all!

 

[lofreqq]

Would the cam sensor or the crank position sensor being bad cause it to fire on only 2 cylinders ?

 

[Indian]

If you can narrow down wich 2 cylinders are missing,then it would be easier to figure out. If the coil is only firing 2 companion cylinders,it will narrow the problem. The mechanic should have tested the resistance before throwing on a new coil anyway.

 

[aspekt9]

I'm going to go out on a limb and guess power transistor if the coil pack has been changed and the ECU checked. Check the wires going into the power transistor plug and verify the pins haven't become dislodged, I've seen it happen before.

 

[lofreqq]

If you can narrow down wich 2 cylinders are missing,then it would be easier to figure out. If the coil is only firing 2 companion cylinders,it will narrow the problem. The mechanic should have tested the resistance before throwing on a new coil anyway.

He said it was companion cylinders that werent firing. He said he switched the wireing on the coil and got the other 2 to fire so he is thinking its the ECU not sending signal. Before i go changing the ECU i wondered if the cam position sensor or the crank position sensor could make it fail to send a firing signal to the coil ? I guess im trying to eliminate the cheaper options first....

Thanks !!!

I'm going to go out on a limb and guess power transistor if the coil pack has been changed and the ECU checked. Check the wires going into the power transistor plug and verify the pins haven't become dislodged, I've seen it happen before.

Forgive the dumb question but where is the power transistor ?

Thanks !!

 

[mtchll]

Yeah check out that power transistor. I had this problem happen to my car and the shop started throwing out all of these possibilities and things they had to check. Of course the last thing they checked was the PT

 

[smrogers5771]

hmmm....... sounds like CAS

 

[chaggard27]

Funny enough I am working on a car right now for a guy with the same exact problem! I switched the wires as well and it fired on the other side of the coil. I also changed the PT with a working one out of my car and the same thing happened. The thing is there is no CEL which makes me believe it would be the MPI relay or the ECU. I have a replacement for both so I am going to test out my theory tonight and see what happens. Also I did check wiring and when the key is on I get power to all three wires on the coil plug and also to the 3 wires on the PT plug so I know it is not a power issue. I believe it to be MPI or ECU. Will update tonight

EDIT:Ok so I ran home on lunch to test the ECU and MPI relay. I replaced them both really quick and tried to crank it over. No go my friends...not sure if it is still only one side that has spark since I didnt have the time to check but all I know is that it didnt fire up. I will be changing out the CAS tonight as well since that is one of the last things to check