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

first, the ECM calculates injector pulsewidth, thats the data to look at. Dutycycle is calculated by PLC as a way to look at where you are relative to injector capacity.

second, the injector pulsewidth is really high, this is a max race, stock MAF chip, so at 10 psi it will be seriously overfuelled. set PLC to a couple frames before it gets erattic and
step thru it using the arrow keys. On the data page watch ECM AFR and RPM.

Bob
 
The chip is a max-race 80lb chip for a stock MAF, a combination that works well, but has to be driven like a race car. The stock MAF runs out of range at 255 gram/second of airflow, so beyond that (way beyond that on this car) you deliver fuel based on RPM and a target boost/HP level. When holding it in a lower gear and feathering the throttle, the top-end fuel starts to come in and overfuel the engine. Its possible to balance the part throttle and full throttle in this situation, but it takes a bit of work.

I discussed this with Eric, and since the OP has upgraded to a Translator and 3.5" MAF as part of the ongoing work, an Extender Extreme chip makes more sense, as it will read all the airflow and deliver a proper amount of fuel at all throttle angles.

Relative to stepping up to a different control system, thats a matter of personal preference and how the car is intended to be used. For the OP's use, I think staying with the stock ECM and an extended range chip is a good choice. Once you step into a Speed Density system (of whatever flavor) you either need to learn to tune it yourself, or hire someone.

Bob

Im having a stalling issue when lifting off the throttle after boost, 5ps-10 psi for about a block of driving, dtarts right up after the stall. I had stock maf, so I upgraded to 3.5 maf translator and tt chip for stock injectors , all stock car, are you saying I should have ordered the extender? i dont have a power logger. i have not installed the parts is the reason I ask.


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Im having a stalling issue when lifting off the throttle after boost, 5ps-10 psi for about a block of driving, dtarts right up after the stall. I had stock maf, so I upgraded to 3.5 maf translator and tt chip for stock injectors , all stock car, are you saying I should have ordered the extender? i dont have a power logger. i have not installed the parts is the reason I ask.


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No, your new stuff will work fine together.
 
Im having a stalling issue when lifting off the throttle after boost, 5ps-10 psi for about a block of driving, dtarts right up after the stall. I had stock maf, so I upgraded to 3.5 maf translator and tt chip for stock injectors , all stock car, are you saying I should have ordered the extender? i dont have a power logger. i have not installed the parts is the reason I ask.


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no, the extender stuff is the solution to problems created by big injectors. with an all stock, or mostly stock car, the standard stuff range works really well.

Bob
 
Wow! Thank you Mr. Bob, always learning something from your posts. So that's why we all have translators and 3.5" MAF then. Thanks that makes a lot of sense now!!


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We have Translators to enable us to use modern/more reliable maf sensors. The Extender and Extender Extreme chips have the ability to extend the range of the maf sensor so we can read true airflow all through the rpm range. It has always baffled me as to why anyone with a Translator or Translator Plus would use a Turbo Tweak chip. The Translator and Translator Plus are complimentary to the Extender and Extender Extreme chips.
 
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We have Translators to enable us to use modern/more reliable maf sensors. The Extender and Extender Extreme chips have the ability to extend the range of the maf sensor so we can read true airflow all through the rpm range. It has always baffled me as to why anyone with a Translator or Translator Plus would use an Turbo Tweak chip. The Translator and Translator Plus are complimentary to the Extender and Extender Extreme chips.

Just to be clear...I didn't make the call on the chip. This motor (as Bob said) is far from stock and I have had a Translator plus since the beginning on this car and this is the first time I have learned about the extender chip. I went with Eric and Nick's recommendation on the chip and wasn't even part of the conversation. It does make complete sense and I am very hopeful that we may have solved this problem...I believe the new chip is supposed to arrive on Thursday so hopefully I will be able to get some time to spend on the car later in the week so I can report back with some good news! Once again I thank all of you for spending so much time to help me solve this problem! I will report back with a log as soon as I get the new chip!
 
Eric his chip number is 13786. 5.7 race 23/22 114 octane 25+psi in the chip


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Thanks Scott...I forgot that you and I were discussing this chip and that I sent you a picture of it a while back! My head has been in a fog for the last couple of weeks dealing with family and work so this problem has taken a back seat even though it is still on my mind constantly!
 
We have Translators to enable us to use modern/more reliable maf sensors. The Extender and Extender Extreme chips have the ability to extend the range of the maf sensor so we can read true airflow all through the rpm range. It has always baffled me as to why anyone with a Translator or Translator Plus would use an Turbo Tweak chip. The Translator and Translator Plus are complimentary to the Extender and Extender Extreme chips.

Wow! I had no idea! This is why being somewhat of a newb sucks. Cause there's so much you just don't know unless your told!

Man these cars need to come with seasoned instructors. In other words, us newer guys should arrange or find some way of having some more experienced guys mentor us through a certain amount of this process. In that, it is very hard to obtain some of this information! Either that, or someone should write a big book. Heaven knows we have enough knowledgeable folks around here to do it that's for sure.

Thanks for the info man, as I had no idea.


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It has always baffled me as to why anyone with a Translator or Translator Plus would use an Turbo Tweak chip. The Translator and Translator Plus are complimentary to the Extender and Extender Extreme chips.

Easy reason for me. The Extender chips dont have closed loop WOT operation like the 6.1. That one feature kept me out of trouble last fall when I was over 10psi low on fuel pressure at full boost.



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Wow! I had no idea! This is why being somewhat of a newb sucks. Cause there's so much you just don't know unless your told!

Man these cars need to come with seasoned instructors. In other words, us newer guys should arrange or find some way of having some more experienced guys mentor us through a certain amount of this process. In that, it is very hard to obtain some of this information! Either that, or someone should write a big book. Heaven knows we have enough knowledgeable folks around here to do it that's for sure.

Thanks for the info man, as I had no idea.


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I think the good news is that these cars are very simple if you are trying to just stay stock or close to stock, there is a simple recipe that is very well documented here and it works. The bad news is that once you get bitten by the bug with these cars very few people are actually happy with stock horsepower even though stock is a strong machine! On the other hand it is VERY rare to find a car that has not been tampered with in some form or fashion and unless you know the entire history of the car and or who was working on it you never know where to start when something goes wrong.

As you know from this thread my car is far from stock and is pushing the limits (arguably by some) and I am learning a lot every day and every time I have a problem I learn even more. Of course I could just install a fast system and take away a lot of these issues however I am still trying to leave some of the original car just because I want to keep some things original just to say there is still some originality to it. Of course if Bob or Eric were to tell me that it is ridiculous to try to use the stock ECM with the setup I have then I would change it but from what they are telling me it is still possible and still well within the range of what the stock ECM can handle.

In the end having Bob and Eric on hand to help teach me (and us) about these cars is absolutely amazing and I am all ears when it comes to others teaching me about the wonderful and sometimes frustrating world of Turbo Buick's.
 
Easy reason for me. The Extender chips don't have closed loop WOT operation like the 6.1.
That's a good reason. I had the same problem several years ago and I instantly recognized what was happening because the car fell on its face. All I needed to do was let off the gas. No problem right. It really is that easy because it is so obvious. My problem was that there was a car in the lane next to me on the street that I was overtaking. I had the knowledge that I needed to let off the gas,but not the ability. It ruined the bearing in the turbo.
 
That's a good reason. I had the same problem several years ago and I instantly recognized what was happening because the car fell on its face. All I needed to do was let off the gas. No problem right. It really is that easy because it is so obvious. My problem was that there was a car in the lane next to me on the street that I was overtaking. I had the knowledge that I needed to let off the gas,but not the ability. It ruined the bearing in the turbo.
Yea I know the feeling :) I can tell you that the wideband closed loop WOT operation works pretty well in Eric's 6.1 chip. I was determined enough (dumb enough) to run 4-5 passes knowing my fuel pump wasn't keeping up. I pegged the WOT base fuel in the chip (170) and the 6.1 still had to ramp up the duty cycle trying to keep me in check. I was actually pretty impressed. Nothing on XFI im sure but impressive for a chip. XFI could have compensated based on fuel pressure. Check this view out. Dont mind the lean blip early in the run. That was from hitting the TR6 rev limiter on the 2-3 shift. Notice I'm at least 13 psi low on fuel pressure in that frame. Idk what actual boost was but I would say that's close. TT 6.1 did pretty good considering just how bad it was being tested.
 

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Yea I know the feeling :) I can tell you that the wideband closed loop WOT operation works pretty well in Eric's 6.1 chip. I was determined enough (dumb enough) to run 4-5 passes knowing my fuel pump wasn't keeping up. I pegged the WOT base fuel in the chip (170) and the 6.1 still had to ramp up the duty cycle trying to keep me in check. I was actually pretty impressed. Nothing on XFI im sure but impressive for a chip. XFI could have compensated based on fuel pressure. Check this view out. Dont mind the lean blip early in the run. That was from hitting the TR6 rev limiter on the 2-3 shift. Notice I'm at least 13 psi low on fuel pressure in that frame. Idk what actual boost was but I would say that's close. TT 6.1 did pretty good considering just how bad it was being tested.
What did you do to restore your pressure?
 
What did you do to restore your pressure?
Nothing yet car cruised around for the rest of the year until put up for winter hibernation. I have racetronix DP 340s and new AN lines for the new engine build and will be dual feeding rails with external reg :)

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Wow! I had no idea! This is why being somewhat of a newb sucks. Cause there's so much you just don't know unless your told!

Man these cars need to come with seasoned instructors. In other words, us newer guys should arrange or find some way of having some more experienced guys mentor us through a certain amount of this process. In that, it is very hard to obtain some of this information! Either that, or someone should write a big book. Heaven knows we have enough knowledgeable folks around here to do it that's for sure.

Thanks for the info man, as I had no idea.


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Newb is an "understatement"
LOL
 
Nero328, did you ever narrow down the issue that was causing all your problems? I'm having very similar problems..
 
Nero328, did you ever narrow down the issue that was causing all your problems? I'm having very similar problems..

I hate to answer for him, however, Nero’s hardly on here anymore.

Not to speak for him, but, his problems ended up being far deeper than first imagined. As his car is now up North with Steve V where his “freshly built motor” is bow being “Fully Rebuilt”. So, you might hit Steve V up or check out his Facebook page and you can see what all he’s done to Nero’s car. As it’s an extensive list of stuff.

Hopefully Nero will start getting back on here again once his car’s issues are resolved?

Good luck with yours!!


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