Help with knock log included

Rob Lyons

Member
I'm getting some weird knock with a gn I just picked up. Short story is I picked up this gn and after going thru it and replacing what leaked or didn't work I pretty much brought the car back to stock engine wise. Once everything seemed fine I started to check out all the parameters and everything checked out on the powerlogger. Right now what I have is a stock turbo, stock fuel pump no hot wire kit, stock injectors, lt-1 maf with translator. I didn't mention the chip because I had a chip with the same engine parameters as what I have the only thing different is that the chip was burned for a lock up transmission and torque and I have a extreme automatics stage 2 non lock up with a 2800 stall non lock up torque attached to the engine because the stock one gave out so I put this one I had for my other gn in it. Now to the knock issue. The car idles fine and even drives fine at low speeds and gears. Everything parameter wise is also fine when cruising around town. However when you decide to get in it it will pick up and boost strong for a little bit then when it seems like it should either swithch gears or just keep pulling all of a sudden it starts to knock retard and act like it won't pull or shift anymore. I've included a log hopefully its not to long.
 

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michael evans

Well-Known Member
I would first get a fuel pressure gauge either where I can see it or log it.

The fuel pump that old might be giving up.

Have you checked the fuel filter ?
 

Rob Lyons

Member
My fuel pressure gauge hose just went out. It’s been stored up for about a year. I replaced the fuel pump with a stock replacement from oreily’s. I also did the fuel filter. As far as the injectors I put some 28lb injectors that were working for me right before I switched to e85. Can you see the log fine.
 

michael evans

Well-Known Member
My fuel pressure gauge hose just went out. It’s been stored up for about a year. I replaced the fuel pump with a stock replacement from oreily’s. I also did the fuel filter. As far as the injectors I put some 28lb injectors that were working for me right before I switched to e85. Can you see the log fine.
No, I no loner have that program that let me.
I have XFI now.
 

dynoman

Well-Known Member
You switched to E85 with no other mods to the fuel system & chip ?? 28 lb injectors will not be big enough for E85 , plus you need a chip burned for it .
 

Nigel

Well-Known Member
Just some observations, hard to tell without actually driving the car.
Looks like 3rd gear does not hold, either that or there is something wrong with the data, I am guessing third gear.
For a stock turbo, I would put a stock converter back in, or look at getting a Husek L/U that is tight enough for the stock turbo.
I would not use a set of old injectors without having them cleaned and checked, Chuck Leeper on the board services injectors for a good price.
Get a modern turbotweak chip or Bob Bailey chip. Your chip has too much timing.
Read the Vortex Buick website and also search the board for getting everything set right, TPS, IAC, Fuel Pressure, TV cable. TPS is either wrong or you are not going full throttle. Is the TV cable adjusted correctly? This could be contributing to the 3rd gear problem.
You have no 3rd gear switch or it does not work. ECM has no input to lower timing in 3rd. I would put the 3rd and 4th gear switches back in for a stock car.
No MPH to ECM, I would fix this. A turbotweak chip would use MPH to lower high gear timing.
Do you have the translator set correctly to deliver a stock range MAF signal to the ECM?
What is the boost level?
 

Rob Lyons

Member
Sorry guys haven't been getting the email alerting me of the responses. So, here is an update. I just finished fixing the speedometer issue and took it out and recorded two more runs. My observation off of both runs is that at part throttle it picks up and pulls like a champ. However, as soon as I stomp on it my knock sensor flies through its lights all the way to red. One run is on the freeway and the other right when I took off. I do agree that I have to get the injectors cleaned as they run fine and register fine with the stock fuel pump on my powerlogger but now the idle is ruff. Im thinking of just grabbing a new set from my local auto part store, takes 30 min to swap. And, I will be emailing Eric right after this post to see if I can get another chip for it.
 

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Rob Lyons

Member
I will now check in every hour to see the responses as I check the parts section. At first I was getting emails every time somebody responded, I don't know why Im not getting any now. I check the parts section every chance I get so I'll probably be around. I do appreciate the help and responses
 

michael evans

Well-Known Member
I will now check in every hour to see the responses as I check the parts section. At first I was getting emails every time somebody responded, I don't know why Im not getting any now. I check the parts section every chance I get so I'll probably be around. I do appreciate the help and responses
I was doing the same thing before I found out you had to "mark forums read " before the board would E-mail you again.
 

Nigel

Well-Known Member
The main thing I see is it looks like 3rd gear is slipping bad. Your TPS is way off if you are at full throttle. It should read around 4.3 to 4.5 WOT.
So from what I can tell every time you step on it in 3rd, or when it shifts to third, the rpms step change up to 5000 plus rpm, which is not normal. Something is bad I believe in the trans. The sudden change in noise, or possibly the trans making noise is likely setting off the knock sensor. I can't tell if it is step changing in the lower gears like that, if it is doing that in the lower gears maybe the converter is bad, but it looks like from what I can see third is not holding. Is the TV cable set correctly?
 

Rob Lyons

Member
The main thing I see is it looks like 3rd gear is slipping bad. Your TPS is way off if you are at full throttle. It should read around 4.3 to 4.5 WOT.
So from what I can tell every time you step on it in 3rd, or when it shifts to third, the rpms step change up to 5000 plus rpm, which is not normal. Something is bad I believe in the trans. The sudden change in noise, or possibly the trans making noise is likely setting off the knock sensor. I can't tell if it is step changing in the lower gears like that, if it is doing that in the lower gears maybe the converter is bad, but it looks like from what I can see third is not holding. Is the TV cable set correctly?
I believe the tv cable is set right. Set to factory specs Push pull then stomp on gas. I do see the tps not reading at wot, at idle it seems fine But at the higher speeds the readings seem low to me. The transmission is an EA stage 2 and has worked very well for me over the past two years. It kicks ass in all the other gears I would hate to have to pull for a freshen up but it is what it is.
 

Pronto

Chaos is a ladder.
Do a koeo slow sweep of the accelerator pedal and watch the tps on the scanmaster. It may have a dead spot or just be adjusted wrong.
 

Nigel

Well-Known Member
I believe the tv cable is set right. Set to factory specs Push pull then stomp on gas. I do see the tps not reading at wot, at idle it seems fine But at the higher speeds the readings seem low to me. The transmission is an EA stage 2 and has worked very well for me over the past two years. It kicks ass in all the other gears I would hate to have to pull for a freshen up but it is what it is.
Post in the transmission section and look to get some help on trouble shooting that. I ended up installing temp and press sensors for the transmission. I did not want gauges everywhere so I installed an innovate SSI-4plus as a clean way to monitor and log since I am still running a stock ECM and powerlogger aux inputs are full. It was a PIA put now I can monitor trans health. I have the temp in the cooler return for now, but plan to relocate to the pan next time I pull the pan. You can always hook up a manual gauge to check pressure. I would pull the pan and check the fluid. If third is slipping you may have burnt fluid and more clutch material than normal. I am sure others who know more about the trans can help with trouble shooting to make sure of a problem prior to dropping it.
With WOT, the TV cable should be tight, not bending the bracket tight, but tight enough to make sure the TV is getting full stroke at WOT.
 

Pronto

Chaos is a ladder.
Looks to me like you're having an issue with the translator and/or maf and your tps is low for wot. MAF is way low...
 
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