New Engine Codes

[Fubar]

I'm not what is causing this. Obviously a problem with the coils but it didn't surface before the mile. I noticed yesterday on a hard pull that the car went flat in 4th gear. I reproduced the problem, looking closely at the gauges. Here is what I noticed at the point or just after the engine seemed to go flat:

RPMs: 5000-5300
Boost: 20lbs
Eng temp: 178, thermostat trip setting
Outside temp: 55 F
A/F reading: 18.5 max dial reading

The car was not running lean prior to this problem and did not run lean on the way home. Today I re-tested the car to see if it continued to do this. It did, but I also got some engine codes this time.

Via the SCT tuner:
P0351 IG COL A
PE SEC CIR ER

P0353 IG COL C
PE SEC CIR ER

P0354 IG COL D
PE SEC CIR ER

P0355 IG COL E
PE SEC CIR ER

P0356 IG COL F
PE SEC CIR ER

P0356 IG COL G
PE SEC CIR ER

P0357 IG COL H
PE SEC CIR ER

Thoughts?

 

[BlackICE]

If you are using a Motec and not your stock ECU to run your coils the answer is simple. The stock ECU monitors the coils drivers and if the current draw is not as expected you will get coil failure codes. Part of OBDII. I doubt is all of the coils failed, but one. Are you still using the stock ECU?

 

[Fubar]

The stock ECU is still driving the coils. Motec is my next project, it is waiting on my Obamaid check.

 

[nota4re]

A/F reading: 18.5 max dial reading

What do you mean when you write this? (More details, please.)

What do your sparkplugs look like? What are they gapped at?

 

[HHGT]

I got this for an answer on another forum re. a 5.4L question.... My be its a harness short???

"Definitely not the Coil or Injector. It's in the harness. Look down by the AC accumulator first. Make sure the harness is not contacting the top of the accumulator - If it is , pull it away and give wires a visual for apparent damage. Then tie the harness away from the accumulator. The MAG field creates havoc on our Ignition systems."

 

[Fubar]

What do you mean when you write this? (More details, please.)

I have an A/F gauge on my dash. The indicator went very very lean with this happened. Anytime you see a lean situation, especially under heavy load, it is cause of concern. However, I suspect that several cylinders failed to fire in rapid succession. This caused the exhaust to go rich, instead of lean... I have been told that O2 sensor can read lean when they become "doused" with fuel. Basically the sensor is covered in fuel and therefor cannot measure any O2 in the air... just a theory.

What do your sparkplugs look like? What are they gapped at?[/QUOTE]The spark plugs looked fine when I got back to the house. They are gapped really tight .17 - .18 but that is what produced the best numbers on the dyno. My concern would be that gapping them this short plays havoc on the coil? I don't know.

I got this for an answer on another forum re. a 5.4L question.... My be its a harness short???

"Definitely not the Coil or Injector. It's in the harness. Look down by the AC accumulator first. Make sure the harness is not contacting the top of the accumulator - If it is , pull it away and give wires a visual for apparent damage. Then tie the harness away from the accumulator. The MAG field creates havoc on our Ignition systems."

I agree that it is not the coil. There is just no way they would all fair at the same time. I check the harness. Thanks for the suggestion. I haven't had much luck with google on this topic yet.

 

[BlackICE]

A lean reading can happen whenever you get a misfire. The O2 sensor reads the O2 level in the exhaust stream. Rich mixtures have lower O2 levels, lean mixture have high O2 levels. I misfire doesn't burn any of the O2 in the cylinder thus the O2 ppm is higher than normal.

As for the coils all OBDII systems monitor the coils current draw and if it is not what is expects the ECU will throw the trouble codes you have. The problem is as HHGT stated most likely bad wiring somewhere. All of the coils have a common +12v source and each coil is grounded for about 1.5ms then the circuit is opened to produce a spark. Multiple sparks are generated at low RPMs (maybe less than around 2000). The ground circuit is internal to the ECU. Note that the common +12 source for the coils is also used for the injectors.

I am intimately aware of the +12v wiring in this area because of my work with Shadowman on the Traction Control System. I am now looking into a spark dwell and timing and knock control system with realtime cylinder pressure monitoring so am also had to study up on the ignition system of the FGT.

Suspects

1. Bad electrical connection to the coils.
2. 7 bad coils (unlikely)
3. Bad ECU (coil drivers)

 

[HHGT]

a lean reading can happen whenever you get a misfire. The o2 sensor reads the o2 level in the exhaust stream. Rich mixtures have lower o2 levels, lean mixture have high o2 levels. I misfire doesn't burn any of the o2 in the cylinder thus the o2 ppm is higher than normal.

As for the coils all obdii systems monitor the coils current draw and if it is not what is expects the ecu will throw the trouble codes you have. The problem is as hhgt stated most likely bad wiring somewhere. All of the coils have a common +12v source and each coil is grounded for about 1.5ms then the circuit is opened to produce a spark. Multiple sparks are generated at low rpms (maybe less than around 2000). The ground circuit is internal to the ecu. Note that the common +12 source for the coils is also used for the injectors.

I am intimately aware of the +12v wiring in this area because of my work with shadowman on the traction control system. I am now looking into a spark dwell and timing and knock control system with realtime cylinder pressure monitoring so am also had to study up on the ignition system of the fgt.

Suspects

1. Bad electrical connection to the coils.
2. 7 bad coils (unlikely)
3. Bad ecu (coil drivers)

i'm guessing 1.

 

[Fubar]

Weird that the problem comes on at higher rpm. I would think, bad wiring is bad all the time. Also, I can't get the problem to reproduce in lower gears (1st, 2nd or 3rd). I've only noticed it in 4th... no roads long enough to test 5th or 6th @ 5300 rpm.

 

[BlackICE]

Weird that the problem comes on at higher rpm. I would think, bad wiring is bad all the time. Also, I can't get the problem to reproduce in lower gears (1st, 2nd or 3rd). I've only noticed it in 4th... no roads long enough to test 5th or 6th @ 5300 rpm.

Good point about the wiring.

Aren't there some good roads in nearby in Mexico where all of the video are shot?

I would try a regapping to 0.025 (preferably with new plugs) and see if the problem persist. Easy to do and removes any question about the gap causing the problem.

 

[911teo]

Weird that the problem comes on at higher rpm. I would think, bad wiring is bad all the time. Also, I can't get the problem to reproduce in lower gears (1st, 2nd or 3rd). I've only noticed it in 4th... no roads long enough to test 5th or 6th @ 5300 rpm.

Used to happen to me as well...

4th gear... pulling from 3k, under load. Never in 1st, 2nd, 3rd, no matter how hard I'd push it. I could not try it in higher gears either for lack of road.....

We checked all the coils, plugs, gaps, wiring etc. Nothing....

Eventually we opened it up... A rocker had failed.... The intake valve in one cylinder was not opening.... hence running lean and causing a misfire (or at least this is what the ECU was seeing and reporting, giving me the yellow check engine light on the dash and going into limp mode for 30 seconds)

The engine still dynoed 635HP with a pulley.... and I would have never noticed it had I driven the car in less "spirited" way.

I hope yours is a much simpler cause.....

 

[paul b]

Did you do a compression test, I wonder if the readings would be different in a two valve head and a 4 valve head. Would one good intake give a good reading?

 

[Fubar]

Eventually we opened it up... A rocker had failed.... The intake valve in one cylinder was not opening.... hence running lean and causing a misfire (or at least this is what the ECU was seeing and reporting, giving me the yellow check engine light on the dash and going into limp mode for 30 seconds)

Do you remember if you got a full array of cylinder codes or just one code from the cylinder with the bad valve? No compression test yet. I plan to do some data logging today, after the usual monday morning grind... and of course the first-freeze pool problems I found this morning. :ack

It's 8am and I already need a stiff drink.

 

[B.M.F.]

You got a kenne bell boost a spark on it?

 

[Fubar]

Yes.

 

[B.M.F.]

try maken a pull with out it on? I have seen these coils handle 38lbs of boost and 1200+rwhp with out a b.a.s. And a oem pcm

 

[BlackICE]

The BAS can be the cause. The ECU will see more current flow than stock with the BAS and then may throw error codss. These OBDII ECU sometimes are too smart.

 

[paul b]

As long as things are still up in the air, just for the hell of it, why not try switching fuel pump relays.

 

[911teo]

Do you remember if you got a full array of cylinder codes or just one code from the cylinder with the bad valve? No compression test yet. I plan to do some data logging today, after the usual monday morning grind... and of course the first-freeze pool problems I found this morning. :ack

It's 8am and I already need a stiff drink.

If I remember correctly it was not giving us any clues that it was related to one cylinder hence the coils test and replacing the plugs, checking the gaps and testing all the coils.. sorry...

 

[MoTeC Magic]

try maken a pull with out it on? I have seen these coils handle 38lbs of boost and 1200+rwhp with out a b.a.s. And a oem pcm

I believe it's the BAS as well. The ignitiors may have some sort of built in heat or over-volt protection resulting in them shutting down??? Not sure yet. The first test is to try with the BAS out of the equation.

The ignition system will support more wHP especially on turbo applications where the hp drag from the SC is not lost. The ignition systems aren't that strong though... just about every trace I've seen has a wavy power curve from about 5,000RPM on, even with smoothing set to the highest values. It's an inductive ignition and not a CDI, the weaker spark energy just comes with the territory of inductive ignition systems.

All the best guys