Engine Cuts out and stumbles under boost...HELP PLEASE! `

[Nero328]

Did you disconnect the orange ECU wire before you re-seated the chip?

yes I did

 

[Nero328]

No trees were harmed in the sending of this message, however, a significant number of electrons were terribly inconvenienced.

Yes, we pulled that one as well while I was in Phoenix

 

[Ttype6]

The only fusible link on the battery + is for ECM power. The rest of the vehicle has the fusible links connected to the starter solenoid B+ terminal. They need to be unbolted in order to replace the starter.

RemoveBeforeFlight

The positive cable from the battery is also connected to that terminal.

 

[Nero328]

The positive cable from the battery is also connected to that terminal.

Ok, that is not what is connected to the terminal on my starter...I will have to take a picture of it however the battery terminal is on its own leg. I don't really think that is my issue here however it is strange that there is only the positive battery terminal and maybe one more wire on that post.

 

[Ttype6]

Ok, that is not what is connected to the terminal on my starter...I will have to take a picture of it however the battery terminal is on its own leg. I don't really think that is my issue here however it is strange that there is only the positive battery terminal and maybe one more wire on that post.

It's been a while,but aren't the link wires hooked to the large lug on the starter along with the positive cable?

 

[Heskahoka]

It's been a while,but aren't the link wires hooked to the large lug on the starter along with the positive cable?

They should be.

 

[GNRick]

Ok, that is not what is connected to the terminal on my starter...I will have to take a picture of it however the battery terminal is on its own leg. I don't really think that is my issue here however it is strange that there is only the positive battery terminal and maybe one more wire on that post.

My car had the 3 fusible links soldered to a single wire that went to the starter.

 

[GNRick]

I once had a problem with the ECM losing power and the car backfiring. New plug wires solved the problem.

 

[Nero328]

I once had a problem with the ECM losing power and the car backfiring. New plug wires solved the problem.

I can definitely understand new plug wires fixing a backfiring issue but New plug wires solved the problem of your ECM losing power too? I am not questioning you, I am questioning these cars. Are they that strange that plug wires would cause the ECM to wig out and lose power?

This whole problem just baffles me. I have replaced everything but the harness in this car and perhaps that is what is needed next? Please understand that this is a new problem and not one that I have been fighting for three years...it has been one thing after another and this is just the latest issue. I started to type out the saga and then I realized that's not what this thread is about so I deleted it all but maybe one day I will start a thread about the saga of this GN just to warn people about the worst possible experience. I love this car and will not give up and I am not a newbie but this thing has kicked my butt!

 

[achalmersman]

Plug wires themselves cannot cause the ecm to loose power. They can cause RFI that causes the ecm to reboot looking in a log like it lost power. Your logs dont show any signs of the ecm actually rebooting.

No trees were harmed in the sending of this message, however, a significant number of electrons were terribly inconvenienced.

 

[RmvBfrFlght]

It's been a while,but aren't the link wires hooked to the large lug on the starter along with the positive cable?

Yes they are, just like I posted previously in this thread. Which you claimed/replied that they were not attached to the starter solenoid, but to the battery terminal.

Same as you disagreeing that a low to zero O2 voltage isn't evidence of a possible fuel delivery failure. If lack of fuel doesn't cause a low O2 (NB) voltage reading, then what does a lack of fuel show at the O2 sensor voltage?

Once Nero328 gets the fuel pressure sender connected to the PL we will know for sure whether there is a fuel delivery issue or not.

RemoveBeforeFlight

 

[achalmersman]

He already did and it looks to be stable. Not exactly 53 psi at 10psi boost, but its stable and not dropping off. Showing 49psi at 10psi boost, and 53psi at 13 psi boost.

No trees were harmed in the sending of this message, however, a significant number of electrons were terribly inconvenienced.

 

[Ttype6]

Which you claimed/replied that they were not attached to the starter solenoid, but to the battery terminal.

I was speaking about Nick's bewilderment that the starter would stop the flow of current from the positive battery cable to the linked wires. My reply was that the starter can't stop the flow of current from one to the other because they are connected together. I never said they were not attached to the starter. I never said they were attached to the battery terminal,but technically they are.

Same as you disagreeing that a low to zero O2 voltage isn't evidence of a possible fuel delivery failure. If lack of fuel doesn't cause a low O2 (NB) voltage reading, then what does a lack of fuel show at the O2 sensor voltage?

I said very specifically that there was no evidence that an inadequate amount of fuel was being delivered to the fuel rail. I then pointed out that the o2 sensor numbers were falling because the computer was rapidly and erratically changing the on and off times of the injectors because of the erratic rpm signal it was being fed. When the computer decreases the on time of the injectors,the o2 will report a lean condition because there is one. Ignition misfire will also cause high levels of o2 to be in the exhaust stream which will cause the o2 sensor to report a lean condition.

Once Nero328 gets the fuel pressure sender connected to the PL we will know for sure whether there is a fuel delivery issue or not.

What achalmersman said. We already knew that fuel delivery wasn't the problem because Nero328 had already observed a fuel pressure gauge at WOT.

 

[Ttype6]

then what does a lack of fuel show at the O2 sensor voltage?

The oxygen sensor measures the amount of oxygen in the exhaust stream. It doesn't know how much fuel is in there. If we don't mix enough fuel with the oxygen entering the engine,the oxygen sensor will see high levels of oxygen because it isn't all used up in the lean burn so it will report a low number meaning high oxygen levels. If we inject the right amount of fuel and the ignition doesn't fire,the oxygen doesn't get used up because there was no fire to use it up. Since the oxygen doesn't get used,it is in the exhaust stream and is reported to the computer also as a lean/low number also meaning there are higher than optimal levels of oxygen in the exhaust stream.

 

[RmvBfrFlght]

The oxygen sensor measures the amount of oxygen in the exhaust stream. It doesn't know how much fuel is in there. If we don't mix enough fuel with the oxygen entering the engine,the oxygen sensor will see high levels of oxygen because it isn't all used up in the lean burn so it will report a low number meaning high oxygen levels. If we inject the right amount of fuel and the ignition doesn't fire,the oxygen doesn't get used up because there was no fire to use it up. Since the oxygen doesn't get used,it is in the exhaust stream and is reported to the computer also as a lean/low number also meaning there are higher than optimal levels of oxygen in the exhaust stream.

Which means that a fuel delivery issue will show up as a lean O2 reading. Which is exactly what I posted.

RemoveBeforeFlight

 

[Nero328]

Plug wires themselves cannot cause the ecm to loose power. They can cause RFI that causes the ecm to reboot looking in a log like it lost power. Your logs dont show any signs of the ecm actually rebooting.

No trees were harmed in the sending of this message, however, a significant number of electrons were terribly inconvenienced.

oh ok...that does make sense. I didn't realize the wires could do the same thing. The old computers are sensitive aren't they?

 

[RmvBfrFlght]

I was speaking about Nick's bewilderment that the starter would stop the flow of current from the positive battery cable to the linked wires. My reply was that the starter can't stop the flow of current from one to the other because they are connected together. I never said they were not attached to the starter. I never said they were attached to the battery terminal,but technically they are.

I said very specifically that there was no evidence that an inadequate amount of fuel was being delivered to the fuel rail. I then pointed out that the o2 sensor numbers were falling because the computer was rapidly and erratically changing the on and off times of the injectors because of the erratic rpm signal it was being fed. When the computer decreases the on time of the injectors,the o2 will report a lean condition because there is one. Ignition misfire will also cause high levels of o2 to be in the exhaust stream which will cause the o2 sensor to report a lean condition.

What achalmersman said. We already knew that fuel delivery wasn't the problem because Nero328 had already observed a fuel pressure gauge at WOT.

Wow, you not only have a reading comprehension issue, but also a writing comprehension disorder.

Do you recall that there are three fusible links coming off the power feed from the starter? And that they deteriorate over time... It is very possible that there is an issue with one or more of these fusible links.

RemoveBeforeFlight

 

[TurboTGuy]

Wow, you not only have a reading comprehension issue, but also a writing comprehension disorder.

Do you recall that there are three fusible links coming off the power feed from the starter? And that they deteriorate over time... It is very possible that there is an issue with one or more of these fusible links.

RemoveBeforeFlight

Why don't you two just do pistols at dawn?

 

[Ttype6]

Which means that a fuel delivery issue will show up as a lean O2 reading. Which is exactly what I posted.

RemoveBeforeFlight

I guess I could say it again. In this case,there is not an insufficient amount of fuel being delivered to the fuel rail. This is exactly what I stated earlier. Nothing else. The problem is that the computer is dispensing the fuel to the cylinders in an erratic fashion because it is receiving bad information.There is no fuel delivery problem meaning the fuel pump,lines, filter,regulator,and voltage are not the problem. The computer is making bad decisions because it is receiving bad information. Corrupt information is the cause of the problem,not fuel supply. The oxygen sensor is delivering low numbers because it senses high amounts of oxygen in the exhaust stream. There is a lot of oxygen in the exhaust stream because of the computer commanding less on time for the injectors and incomplete combustion/misfires.

 

[Geezy]

I guess I could say it again. In this case,there is not an insufficient amount of fuel being delivered to the fuel rail. This is exactly what I stated earlier. Nothing else. The problem is that the computer is dispensing the fuel to the cylinders in an erratic fashion because it is receiving bad information.There is no fuel delivery problem meaning the fuel pump,lines, filter,regulator,and voltage are not the problem. The computer is making bad decisions because it is receiving bad information. Corrupt information is the cause of the problem,not fuel supply. The oxygen sensor is delivering low numbers because it senses high amounts of oxygen in the exhaust stream. There is a lot of oxygen in the exhaust stream because of the computer commanding less on time for the injectors and incomplete combustion/misfires.

Ok, so how do you fix this?


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