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

[Street Lethal]

"SA related in the bin he was using"...can you educate me here please? I am not a newbie however these are terms that I am not aware of.

SA is just the acronym for Spark Advance. If the problem is only happening under boost, and you are absolutely sure that the fueling is there during that boost, as well as the spark plugs, plug wires, ICM, etc, are firing properly, all sensors reading accurately, then it has to be somewhere in your tune. Not sure if disconnecting the battery might have done something in the bin as I have never run that setup, but it would be a good idea to ask the author of that code to look at the tune and see if there is anything off during boost pressure. If your friends are confirming fuel being removed a la low BLM numbers, then the timing may be off during boost leaving excessive fuel in the chambers leading to the symptoms you are describing; cut/sputter/misfire. You didn't mention a different cam sensor in the first post though when you were going through your testing, did you get a chance to try another one since you stated you already tried other ECM's and chips?

 

[Ttype6]

Since we know that the rpm reference signal is bad and the power that the crank sensor uses comes from the module and that low voltage in equals low voltage out when it comes to ignition systems and all of this started with a starter issue,I've been trying to figure out a way to test the fusible link that sends voltage to the ignition without you having to crawl under the car to splice and jumper stuff. Peel back all of the protective tape and what not that is covering the wires to the ignition module. Strip away some of the protective coating on the pink/black wire that is connected to terminal P. Do it on a part of the wire that will be covered when everything is re taped. Terminal P it at one end of the connector. The other end of the connector (terminal A) will have a white wire connected to it. Terminal M also has a pink/black wire connected to it. Terminal M is only two terminals away from P. Don't tap into this wire. Run a jumper from the positive post on the back of the generator to the pink/black wire that is connected to terminal P. This will take the link,the fuse,and the ignition switch out of the equation. Go for a test drive.

I see that the pink/black wire that goes to terminal M is also fed its voltage from the starter. I was thinking that wire went to the cam sensor. Since it gets power from the starter also,you'll want to jump to this wire as well as the pink/black that is connected to terminal P. After you run a jumper from the generator to the wire on terminal P,you can use another jumper to connect both pink/black wires together.

 

[Nero328]

That's too bad. Why is your oil pressure switch and your trans connector disconnected.

The oil pressure switch was disconnected when I bought this car and I don't have the transducer for it. It is an easy fix however I haven't worried about it because I have the gauge in the car and I have been fighting so many other problems I just haven't gotten to it. As for the trans...same story but the transmission I have was built by Art Carr (the California Carr) and he is the one the did the delete on it so I haven't questioned why it isn't connected, I figured he knows FAR more than I do about transmissions with these cars!

 

[turbo87adam]

Another member suggested hot wiring icm with a relay to take load off of ignition switch . This may help

 

[Ttype6]

The oil pressure switch was disconnected when I bought this car and I don't have the transducer for it. It is an easy fix however I haven't worried about it because I have the gauge in the car and I have been fighting so many other problems I just haven't gotten to it. As for the trans...same story but the transmission I have was built by Art Carr (the California Carr) and he is the one the did the delete on it so I haven't questioned why it isn't connected, I figured he knows FAR more than I do about transmissions with these cars!

I assume that Art disconnected the trans connector because you are running a non lock converter,but you won't be able to take advantage of timing and fuel changes that pertain to first and second gear because the computer is always being told that the trans is in fourth gear. It's also nice to see what gear the trans is in when reading a log.

 

[Ttype6]

[Another member suggested hot wiring icm with a relay to take load off of ignition switch . This may help

Actually if you did what I described,you bypassed a problem between the starter and the ignition module because the ignition switch is fed by voltage at the starter.

 

[87GN_Bart]

I am confused, did you pick the car up with the problem if so why did you take it. The head gasket was blown if what you said is the truth but something does not seem right because you don't seem upset after paying for the job. Is there more to the story than you are telling us also you can blow a head gasket at just about any boost level if timing, fuel and program is not correct. Good luck and hope you work out the problem.

 

[Ttype6]

I am confused, did you pick the car up with the problem if so why did you take it. The head gasket was blown if what you said is the truth but something does not seem right because you don't seem upset after paying for the job. Is there more to the story than you are telling us also you can blow a head gasket at just about any boost level if timing, fuel and program is not correct. Good luck and hope you work out the problem.

There's no evidence that anyone involved with this project acted with incompetence,nor is there any suspicion of it. In fact this is a situation where something odd happened while in the hands of competent people.

 

[Nero328]

I am confused, did you pick the car up with the problem if so why did you take it. The head gasket was blown if what you said is the truth but something does not seem right because you don't seem upset after paying for the job. Is there more to the story than you are telling us also you can blow a head gasket at just about any boost level if timing, fuel and program is not correct. Good luck and hope you work out the problem.

Wait...why are you questioning my honesty? Is ranting and raving over the problem going to get me back on the road? I am absolutely upset however like I said, getting pissed off is not going to solve my problem is it? Nick and I will deal with the rest of it privately, and is not something that needs to be discussed here at all.

 

[Nero328]

There's no evidence that anyone involved with this project acted with incompetence,nor is there any suspicion of it. In fact this is a situation where something odd happened while in the hands of competent people.

Thank you Ttype6...not sure what I did or said to deserve my integrity or Nick's integrity to be questioned but I appreciate you clearing that up as well.

 

[87GN_Bart]

Who said anyone was incompetent something is not right, i have been around these cars for 30 years and never seem a head gasket blow on it's own. Someone was driving the car when it happened, i am not blaming anyone that is up to the owner if there is blame to be made.

 

[mikestertwo]

Yes...again I wish it were that simple.

I just thought I would mention it. Usually the solution is simple, finding the cause not so much. I had a customer with a similar problem and the cause was he had moved the grounds from the back of the head to the negative terminal on the battery. It was corrupting the data from the sensors on the motor. I moved the grounds back to the engine and all was well.

 

[Mark E]

Mikestertwo; new to this forum and seriously modding turbo cars but have to agree. In 20yrs dealing with low voltage sensors in industrial environments really irregular signals and ghosts I would look at grounds and shielding first. Then voltage supply, true rms multi meter on the 12v supply's.
Is there a draw on the battery sitting not running? What caused the battery to die? Could there be a problem that would kill the battery and cause this issue when extra load is applied?

 

[Ttype6]

something does not seem right because you don't seem upset after paying for the job.

This statement implies that someone did something with malice or incompetence and should not have been paid for their work. The OP doesn't think this at all. I'm guessing he is upset,but not because of Nick.

 

[Ttype6]

Is there a draw on the battery sitting not running? What caused the battery to die? Could there be a problem that would kill the battery and cause this issue when extra load is applied?

I wonder if the starter was draining the battery since the starter failed so dramatically. Did you view the OP's Powerlogger recordings?

 

[Ttype6]

Could there be a problem that would kill the battery and cause this issue when extra load is applied?

Based on what we know,I think the dramatic failure of the starter did something to caused this problem.

 

[Mark E]

I wonder if the starter was draining the battery since the starter failed so dramatically. Did you view the OP's Powerlogger recordings?

No i didn't. So new to this I figured they d be over my head. The starter having a draw that kills a battery would have gotten hot, who know s maybe it stuck on or the solenoid did. If it got hot, it could have caused damage to the supply leads. Or even hurt a ground burnt it internally or at a connector. I don't know if they d be soldered or just crimp terminals but I have seen solder melt out of connections and still look ok, test ok for continuity and fail with a load or approaching peak amps. Not real common but it seems like this is a strange problem. Peak load has to be under boost, at rpm I would assume. It sounds like it drops so fast I d look more at broken wire or something that looses continuity under torque.

 

[Ttype6]

I wonder if the starter was draining the battery since the starter failed so dramatically. Did you view the OP's Powerlogger recordings?

No i didn't. So new to this I figured they d be over my head. The starter having a draw that kills a battery would have gotten hot, who know s maybe it stuck on or the solenoid did. If it got hot, it could have caused damage to the supply leads. Or even hurt a ground burnt it internally or at a connector. I don't know if they d be soldered or just crimp terminals but I have seen solder melt out of connections and still look ok, test ok for continuity and fail with a load or approaching peak amps. Not real common but it seems like this is a strange problem. Peak load has to be under boost, at rpm I would assume. It sounds like it drops so fast I d look more at broken wire or something that looses continuity under torque.

In the data logs,the rpm signal gets erratic.

 

[Ttype6]

No i didn't. So new to this I figured they d be over my head.

It is not over your head,but you have to download Powerlogger to view the logs.

 

[Mark E]

It is not over your head,but you have to download Powerlogger to view the logs.

I know you guys talked about engine rpm being erratic. I don't know if the logger gets that information from the crank or ignition mod, assuming ignition mods witnessing can make you look stupid.
Either way if I trusted Nick that it ran good after first being installed and it sounds like that's not in doubt I would look at the wiring near the starter real close. If it was mine I might just toss most of it and do new. Fusable links can go bad and still work,