Update and a ask for help on my car.

[J-Groove]

Update, yes, finally an update.

Kinda long, what I really would like some help with is in bold at the bottom.

here is the Thread that details the issues and resolutions up to current.

Car is up and running. Some problems solved, some not yet.

Problems solved, at least as of right now

The most pressing on was a power issue I was having. The new battery terminals I purchased are painted with the power areas non painted. Well they was apparently still enough paint to not allow a decent constant connection, some 60 grit sand paper and everything is looking great.

Right now, no Check Engine Light, this is right, I'm currently CEL free.

My ECU is fine, EricVR4 helped me out and shipped me his ECU out of his car so I could swap them out and see if there was any difference.

And best of all, she is running properly, everything is checking out great. I haven't gotten her into any real boost (only maybe 2psi) but that is also because she hasn't moved in so long. Well everything checked out except for...

Problems

First one, not a big deal. When i installed my down pipe I did it quickly, I need to line it up better, s right now I have some smoke from the rear bank. Also I think my rear turbo is burning some oil. Egh, I bought them used, and I got what I paid for.

The real remaining problem. When I first start the car I have 0 knock, but after I drive her for a little bit she begins her oscillating between 7-9 counts. This count does not change with any RPM, also she is not pulling any timing. (at least not at half throttle and under 4K RPM I haven't gone WOT yet, I don't want to with my knock sensor acting up)

This is a new Knock sensor
It behaved the same way with two different ECUs.

Any ideas? I'm really stumped with this.

Thanks,
-John

p.s. I would go out and drive her more now but I am dead broke and need gas.

Student loan check is late coming in for summer school so I had to pay out of pocket. Which meant draining my savings account. I can't even afford rent this month. My land lord already knows. But still sucks waiting. I should be getting my check in tomorrow though.

[vr4]

check for wiring damage. knock sensor and knock sensor bracket bolts nice and tight. downpipe not hitting anything when its hot?

[Monochrome]

Hmm... Let's get start with the basics.

How old is the gas in the car? Old gas = knock under boost due to the degraded octane.

Have you checked your base ignition timing (with a timing light pointed at the crank pulley)?

How much boost are you currently running?

Have you read my post on knock in the Stickied thread at the top of the Automotive page?

[J-Groove]

check for wiring damage.

Will do, I haven't found any. But I'm all mechanical. So wiring is not my forte. Should I start from the knock sensor connection and work my way back the snake?

knock sensor and knock sensor bracket bolts nice and tight.

Bracket bolts are, I'm more than certain the knock sensor is. I used a torque wrench when putting it in. Though I haven't checked since first installing it. I should also note that I was having the same problem with my old knock sensor. I had assumed it might be a bad sensor and replaced it.

downpipe not hitting anything when its hot?

I had not thought of that. But yes, when I rev there is a slight sound coming from the DP at the rear bank. But if that was the cause, wouldn't the count very with RPM and driving?

Hmm... Let's get start with the basics.

How old is the gas in the car? Old gas = knock under boost due to the degraded octane.

The gas is about 2 months old. And the tank is running low, the light isn't on yet but it is close. I'm running a hot wired Walbro.

Have you checked your base ignition timing (with a timing light pointed at the crank pulley)?

I have not. I'll have to do that.

How much boost are you currently running?

Right now only 6psi. But the knock is constant from idle, and at any RPM. I have used an automotive stethoscope and can not hear any knock.

The engine is a 2bolt TT block, 2nd gen forged crank and rods, 9:1 Ross pistons with N/A heads. Stock 9B turbos and SMIC along with stock FPR and 360 injectors. Hot wired walbro fuel pump.

I do have a SAFCII that I haven't yet installed, not planning on doing so until I have he running properly with stock fuel trims and 6psi

Have you read my post on knock in the Stickied thread at the top of the Automotive page?

yes I have, great thread BTW.

Thanks for the questions and the help. Lets keep it coming.

-John

[Monochrome]

[quote=""J-Groove""]Right now only 6psi. But the knock is constant from idle, and at any RPM. I have used an automotive stethoscope and can not hear any knock. [/quote]


I'm sorry I missed this part...

Check to make sure none of your intake pipes have come off. Specifically the intake pipes to the turbos.

[Hans_GZP]

Is the block overbored for the pistons or are they stock size? If stock size, how many miles were on the block previously and what was wrong with it if anything?

[J-Groove]

[quote=""Hans_GZP""]Is the block overbored for the pistons or are they stock size? If stock size, how many miles were on the block previously and what was wrong with it if anything?[/quote]

The block came out of a 1st gen, it had a cracked piston and bent rod.

To fix everything did a 20 over bore, just wanted to get a piston barley larger so everything would be perfect.

No idea of how many miles were on the block, but had the machine shop do the works on it. It is pared with my stock N/A forged crank and rods, it was a perfectly running engine with 112,0XX miles.

-John

[Hans_GZP]

I asked about overbore because of possible "piston slap" issues. Does it knock if it is cold or only when warmed up? Did the machine shop machine your rods for a floating pin or did they use a press fit pin?

[xeocube]

It sounds more like its not real knock. Maybe one of your electrical lines is crossing with a constant signal of some sort, creating the constant spikes that the ECU interprets as knock. But from what I've heard low knock counts such as this wouldn't really be a problem anyway, and this obviously isn't a problem since the ECU doesn't even pull timing (IE not seeing it as knock).

[J-Groove]

Grayson has been helping me try and figure out my issues for a couple of months now. The 7-9 constant oscillating knock is the default back know sensor code. Since this is the same thing my old sensor did and the new one is doing it as well I'm leaning towards something other than the sensor.

I couldn't resist I had to drive her some tonight.

No CEL, also no injector shut off, so it is really looking like my bad battery connections really messed up my system. She has been going great since I fixed those.

The plan right now is for Thursday. (to much school during the week) I'll be going over to Jeremy's place to have him help and use his garage, fix my exhaust leak. See if that is by any chance causing the knock, if nothing changes we will run wires directly from the knock sensor to the ECU. So instead of trying to find a problem we will just eliminate it right away. Looking at the wiring diagrams there is no pit stop for the knock sensor wires so this should work.

I'm honestly not sure if the shop press fit or they machined my rods. Knowing the shop I'm assuming they did what was best. They are a engine specialty shop, all they do is engines. High end german, asian, and american cars.

-John

[vr4]

what ignition are you running? non-resistor plugs?

[J-Groove]

oem coil pack and PTU, with NKG iridiums gapped to .30.

-John

[xeocube]

[quote=""Hans_GZP""]I asked about overbore because of possible "piston slap" issues. Does it knock if it is cold or only when warmed up? Did the machine shop machine your rods for a floating pin or did they use a press fit pin?[/quote]

But that would increase the number of counts you would get with an increase of RPMs wouldn't it?

[Hans_GZP]

Usually the knock counts would go down with higher rpms because the pistons slap less when revving. Piston slap usually occurs during idle and low rpm (no load) conditions.

Hopefully the isolation of the knock sensor wire will cure it. I would wrap it with something like aluminum foil to prevent rf interference.

[vr4]

piston slap should only be a concern when cold. if properly sized itll go away when warmed up

[xeocube]

[quote=""Hans_GZP""]Usually the knock counts would go down with higher rpms because the pistons slap less when revving. Piston slap usually occurs during idle and low rpm (no load) conditions.

Hopefully the isolation of the knock sensor wire will cure it. I would wrap it with something like aluminum foil to prevent rf interference.[/quote]

Aluminum foil is actually pretty bad at keeping RF away, even more so when it's not grounded to anything. A simple ground wire coiled around it will do more for the signal.

[J-Groove]

Good thinking about adding a second ground to the signal wire.

I'll be making an update on Thursday after I work on her.

-John

[J-Groove]

Well, today she was running great, took her over to Jeremy's place with very simple plans.

1. Tighten the accessory belt so I can use my AC.
2. Fix exhaust leak
3. Then see if knock is still oscillating and if so run direct wires.
4. Go out with Jeremy (Laser) and Chris (Z) and take some pictures.

Did one and two, lowered her back down to start her up and check the exhaust leak and the belt was tight enough. 1 and 2 were a success but the car went back to running like shit. Only good news, knock went away. haha

So, the fixing of the source power and grounds did not completely fix the car, just tricked her into running well for a couple of days.

Jeremy and I tinkered away for the next couple of hours and here si what we have found out.

Injector resistors are wired in properly for sure.
I'm getting no spark for coils 2 and 5, I am for the other 4. Took apart and swaped around the coil pack to see if it was just that terminal, it is not. So the problem is before the coil pack. So we are going to work our way back from there. I'm going out of town tomorrow for 2 days, my car is at Jeremy's. I'm hoping he will get bored and fix my car.

I'll let y'all know. Right now I'm bummed, I'm, on 4 hours of sleep school is long and my car is kicking me in the nuts and stealing my lunch money.

-John

[Hans_GZP]

Try swapping out PTU's (the part located under the coil packs).