Have a wiring issue (Cylinders 1 & 4 are not firing)

[BoostedTsiFWD]

From what i have read this seems to be a common problem with no solution. Am i over reading or what? Tried different ECU's, no go. Tried different transistors, still not it. Maybe its the coil, nope. Is this the result of a bad ground? If it is could someone tell me which wire so i can re ground it.

 

[wrecklessracing]

pm'ed

PM'ed

 

[95blackGsTurbo]

Check to see if you are getting power to the coils. If not check to see if you are getting power to the crank and cam sensors. If they are getting power but not putting out a signal then you have located your problem.

 

[BoostedTsiFWD]

Check to see if you are getting power to the coils. If not check to see if you are getting power to the crank and cam sensors. If they are getting power but not putting out a signal then you have located your problem.

From what i understand from the previous owner the coils have power but one is not getting the signal to fire. One coil does fire though. I have read that the cam and crank sensor isnt what tells which coil to fire. They are just there to help determine fuel trim levels. The ECU sends the signal to fire. Other ECU's have been tried with the same result so my conclusion is a short somewhere or a bad ground.

I will be checking the connectors myself when i get the chance to verify the claims but i do know both the cam and crank sensors are brand new.

pm'ed

PM'ed

PM'ed back

 

[steve]

From what i understand from the previous owner the coils have power but one is not getting the signal to fire.

I have read that the cam and crank sensor isnt what tells which coil to fire. They are just there to help determine fuel trim levels. The ECU sends the signal to fire.

If that's what you gathered from your reading then you didn't understand what you read. The cam and crank sensor are what the ECU bases all it's timing activities on. If the ECU doesn't know where in the otto cycle it is because of a bad cam or crank sensor then it can't fire an injector or coil.

Asking the PO questions is no replacement for grabbing your multimeter and checking it yourself. There is no way either of you can know the answer until you do.

There is a engine speed detection connector under the hood that is connected to the power transistor output for the coil that fires cylinder 1 and 4. Hook a tach up to it and see if you get an RPM from it. If will be half the actual RPM since your only seeing half of the sparks.

Sometimes people "clean" up their engine bay wiring and cut this connector off while disconnected the coil from the PTM. Checking the wiring with the manual and a multimeter will quickly identify if there is a short or open that could be causing your problem.

If you don't know how to do these things, don't skip them, ask.

 

[BoostedTsiFWD]

If that's what you gathered from your reading then you didn't understand what you read. The cam and crank sensor are what the ECU bases all it's timing activities on. If the ECU doesn't know where in the otto cycle it is because of a bad cam or crank sensor then it can't fire an injector or coil.

Asking the PO questions is no replacement for grabbing your multimeter and checking it yourself. There is no way either of you can know the answer until you do.

There is a engine speed detection connector under the hood that is connected to the power transistor output for the coil that fires cylinder 1 and 4. Hook a tach up to it and see if you get an RPM from it. If will be half the actual RPM since your only seeing half of the sparks.

Sometimes people "clean" up their engine bay wiring and cut this connector off while disconnected the coil from the PTM. Checking the wiring with the manual and a multimeter will quickly identify if there is a short or open that could be causing your problem.

If you don't know how to do these things, don't skip them, ask.

I have the receipts for the new parts. I do plan on Checking myself to. And where in the hell is that connector located at. I saw a diagram where 1 and 4 were ran through it but i can not find it for the life of me .

PTM, Power transistor? Is that correct. What setting am i using for my ohms meter and which wire is the one i want to check. Does the car have to be cranking to get a signal or just the acc turned on? I hate asking so many questions at once but im sure its something simple and stupid that won't be but 10 min to fix. Im just not sure which wire i need to check. None of these diagrams seem too help full.

Im probably just reading them wrong.

 

[steve]

Where in the hell is that connector located at. I saw a diagram where 1 and 4 were ran through it but i can not find it for the life of me .

http://www.dsmtuners.com/forums/151542343-post53.html

PTM, Power transistor? Is that correct.

What setting am i using for my ohms meter and which wire is the one i want to check.

Does the car have to be cranking to get a signal or just the acc turned on?

For measuring continuity (resistance), you set your multimeter to the OHM setting and if there is more than one the lowest range. Then look at the display and note what it reads when the probes aren't touching and when they are.

You'll be measuring the resistance of the length of wire between the power transistor and the coil and you do so with the ignition turned off. You don't want and stray voltages on the wires when measuring resistance between two points.
Find the matching pins shown in the wiring diagram at the coil and power transistor module (PTM). In this case they are pin 8 (black with white stripe) on the PTM connector and pin 2 (blue with red stripe) on the coil connector. With the probes touching the pins in the connectors you should see the same reading as with the probes touching. (something like 0.0 ohms)

The next test is to plug the coil connector back in and switch the multimeter to measure volts. Turn the ignition switch on and measure pin 8 at the PTM. You should see battery voltage which indicates that power flowed through the ignition switch to the coil primary winding and out to the PTM. If that measures good, the next step would be to check the coil secondary circuit and the wiring between the ECU and PTM.

I hate asking so many questions at once but I'm sure its something simple and stupid that won't be but 10 min to fix. I'm just not sure which wire i need to check. None of these diagrams seem too help full. I'm probably just reading them wrong.

You seem to have the idea how to read the diagrams if you saw where the connector was.

 

[BoostedTsiFWD]

http://www.dsmtuners.com/forums/151542343-post53.html



For measuring continuity (resistance), you set your multimeter to the OHM setting and if there is more than one the lowest range. Then look at the display and note what it reads when the probes aren't touching and when they are.

You'll be measuring the resistance of the length of wire between the power transistor and the coil and you do so with the ignition turned off. You don't want and stray voltages on the wires when measuring resistance between two points.
Find the matching pins shown in the wiring diagram at the coil and power transistor module (PTM). In this case they are pin 8 (black with white stripe) on the PTM connector and pin 2 (blue with red stripe) on the coil connector. With the probes touching the pins in the connectors you should see the same reading as with the probes touching. (something like 0.0 ohms)

The next test is to plug the coil connector back in and switch the multimeter to measure volts. Turn the ignition switch on and measure pin 8 at the PTM. You should see battery voltage which indicates that power flowed through the ignition switch to the coil primary winding and out to the PTM. If that measures good, the next step would be to check the coil secondary circuit and the wiring between the ECU and PTM.



You seem to have the idea how to read the diagrams if you saw where the connector was.

I dont know too much about using an Ohms meter. Do i connect one point into one pin on the transistor and the other point into the coil pin? Is this correct?

 

[steve]

I dont know too much about using an Ohms meter. Do i connect one point into one pin on the transistor and the other point into the coil pin? Is this correct?

Yes.

Multimeter Tutorial
YouTube - How To Use A Multimeter

 

[BoostedTsiFWD]

Ok both tests that you gave me checked out. My friend got it started once before and he said all he did was wiggle the harness because he had the center console taken apart. It fired right up and ran untill he boosted it for a sec to check the wast gate and turbo i guess. Then it started firing on 2 cylinders again when it revved back down. What wire is under the dashboard that controls that coil because it seems like its grounded out and then where do i need to rewire it to? This seems like the problem. What do you think steve.

Come on guys. This seems like a common problem with no clear solution. Can anyone tell me which wire im suppose to be looking at sense the 2 test he gave me checked out? Im sure its an easy fix and its narrowed down to a small area of wire. 4 i believe. I just don't know which one i should be checking or how to go about checking to see if it sends the 1 & 4 coil a signal.

 

[steve]

If that measures good, the next step would be to check the coil secondary circuit and the wiring between the ECU and PTM.

The coil tests are in the manual for checking the primary and secondary. The secondary side includes the plug wires and plugs.
The pins you need to check for the wiring are in the diagrams you were looking at. Unlike the coil to PTM check there isn't a voltage to measure, just the continuity.

If all the wiring checks out then your looking at a part failure but since it sounds like you have swapped the ECU, PTM, and Coil already you might have to start looking at the cam and crank sensors to see if your not getting the signals the ECU used to decide to fire the coils.

You'll have to run with this. I've got customers to take care of and two cars of my own crying out for attention right now.

 

[BoostedTsiFWD]

The coil tests are in the manual for checking the primary and secondary. The secondary side includes the plug wires and plugs.
The pins you need to check for the wiring are in the diagrams you were looking at. Unlike the coil to PTM check there isn't a voltage to measure, just the continuity.

If all the wiring checks out then your looking at a part failure but since it sounds like you have swapped the ECU, PTM, and Coil already you might have to start looking at the cam and crank sensors to see if your not getting the signals the ECU used to decide to fire the coils.

You'll have to run with this. I've got customers to take care of and two cars of my own crying out for attention right now.

Thanks you've been a great help. Hope i can get it running

 

[1fast97gsx]

Are you guys freaking serious? 1/4 are on the same coil and 2/3 are on the same coil. Swap the damn coils and see if the problem migrates to 2/3. If that's the case you have a bad coil. If not then look into wiring issues, etc.

 

[steve]

Tried different ECU's, no go. Tried different transistors, still not it. Maybe its the coil, nope.

Are you guys freaking serious? 1/4 are on the same coil and 2/3 are on the same coil. Swap the damn coils and see if the problem migrates to 2/3. If that's the case you have a bad coil. If not then look into wiring issues, etc.

Good suggestion but I took his first post to mean that he has swapped ECUs, transistors, and coils. Perhaps he didn't. It wouldn't be the first time somebody fixed it on the second time around.

 

[BoostedTsiFWD]

Good suggestion but I took his first post to mean that he has swapped ECUs, transistors, and coils. Perhaps he didn't. It wouldn't be the first time somebody fixed it on the second time around.

I have tried 2 different coil packs with the same results.

 

[awzer2]

Are you guys freaking serious? 1/4 are on the same coil and 2/3 are on the same coil. Swap the damn coils and see if the problem migrates to 2/3. If that's the case you have a bad coil. If not then look into wiring issues, etc.

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I have tried 2 different coil packs with the same results.

Hey! I was thinking...Could it possibly be a timing problem?
because before the CAS sends info to the ECU,the timing comes first.

 

[BoostedTsiFWD]

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Hey! I was thinking...Could it possibly be a timing problem?
because before the CAS sends info to the ECU,the timing comes first.

That is very possible. I keep checking and checking mine just too make sure its not out of time but in your case i would check also.