Misfire, knocking, pinging?? [Archive]

Redog

12-05-2010, 07:18 PM

Does it mainly when cold.

I'll get on it and it will stumble and the tach goes nuts. I always thought this was a misfire, but now wondering if it's something else.

I use 91 octane, maybe need to go to 93?

P0135 code is on. Need to figure out how to get that light out (it's not the O2 sensor, I replaced that, it's in the programing)

Any ideas:

Newer, plugs, wires, ICM, & coils All about 20,000 miles or less, changing all these didn't make it go away either. Still thinking it's the P0135, but in the programing (HPTuners) I'm kinda lost

Afugy

12-05-2010, 07:25 PM

Why are you running 91 octane in a non turbo?

mfuller

12-05-2010, 08:33 PM

Sounds like an electrical short somewhere.

Cliff8928

12-06-2010, 01:56 AM

Did you ever disable the AIR system with that other PCM installed?

Redog

12-06-2010, 03:27 AM

Why are you running 91 octane in a non turbo?

It's programed to run on 91 octane

Sounds like an electrical short somewhere.

Hmmmmm. wondering where to look first

Did you ever disable the AIR system with that other PCM installed?

Yes it's disabled. I put in the orginal PCM and the HP tuners wouldn't let me license the PCM :(

XanderWiFi

12-06-2010, 07:39 AM

Does it go away when the car warms up?

Someone told me on here once that our pistons will do that until they completely warm up and expand to fill the chamber.

Lucalare

12-06-2010, 09:26 AM

That would explain the sounds, but not the crazy behavior. Definitely sounds like a short somewhere.

clutch1

12-06-2010, 12:27 PM

Check (or get someone to check) the signal from the cam and crank sensors...

Redog

12-06-2010, 06:28 PM

^^ Good idea
What do you need to check that?

I replaced the crank sensor behind the crank pulley/balancer, somehow half the sensor was ripped out of the block :eek: I forget if that's the 7x or the 24x

Stickybuddz420

12-07-2010, 12:09 AM

Does it go away when the car warms up?

Someone told me on here once that our pistons will do that until they completely warm up and expand to fill the chamber.

Yeah mine does that slightly, also the exhaust goes put put for a minute then smoke pours and it idles, this is starting in 20- Deg.

clutch1

12-07-2010, 12:24 AM

Front one behind the pulley is 24x (24 slots on the pulley, if you look at it), the one on the crank itself is a 7x.

So That was the issue??

[ion] C2

12-07-2010, 12:27 AM

Sounds like a vacuum leak..

Someone told me on here once that our pistons will do that until they completely warm up and expand to fill the chamber.
Piston slap, I get it since I have forged aluminum pistons in an iron block... different expansions.
Why are you running 91 octane in a non turbo?
lolz

Redog

12-07-2010, 12:27 AM

No, I had that problem in the winter of '10. I could only go 2000 RPM's or the car would give me problems, Translates to 60 MPH max

My exhaust is going put put put too. Now it's starting to do it after it's warmed up :eek:

WhiteV6

12-07-2010, 12:29 AM

P0135 is not in the programming. You have a short somewhere and its screwing with the computer. If you need help with HPTuners, just email me. Turning off codes isn't going to fix it.

Check the resistance between the PCM connector and the O2 harness connector. Not sure what pins without a wiring diagram but this is what I had to do for a friends achieva that had a #2 cylinder misfire. Bad wire. I couldn't go over 60 mph without it acting like it wanted to break some parts.

Cliff8928

12-07-2010, 12:51 AM

Here ya go...

Redog

12-07-2010, 01:43 AM

That's odd though. I didn't have this probelm with any other PCM I had in the car, just this one. I did swap my stock one back in and I couldn't unlock it with the HPTuners. I figured I could just swap the stock one back in and throw in the program that you already wrote for me and just be done with it.

Is P0135 causing this problem?

Gr1m

12-07-2010, 02:21 AM

i would get the original PCM in the car that was giving you licensing problems and maybe post up on some forums to figure out what the deal is with that error.

clutch1

12-07-2010, 09:44 PM

Ion, it can't be a vacuum leak, vacuum leaks are only at idle, @ speed their effects are negligible at most.

Ken, get someone with an O-scope and monitor voltage on the signal wire of each sensor.. 24x is gonna be a digital (boxes) pattern, and 7x is gonna be an AC waveform... make sure they look legit. Then probably grab a live data scanner and see what the timing advance is... injector pulse, etc... basically any sensors that control driveability.

Like they said, if the comps acting goofy it could be a culprit.

XanderWiFi

12-08-2010, 10:59 AM

Could it be knocking because of the 91 octane? Stock 3400s are rated to have 87 octane. In Texas they only have 86, 88 and 91 respectively. I noticed that I had knocking with the 86 octane but not when I used the 88. Just a little home experiment. Not sure if it has complete validity though.

Lucalare

12-08-2010, 11:01 AM

I doubt you would see negative effects (aside from mileage) by buying a higher grade gas. of course there are limitations, I doubt a stock engine would enjoy running 110 or something (airplane fuel).

[ion] C2

12-08-2010, 11:26 AM

Ion, it can't be a vacuum leak, vacuum leaks are only at idle, @ speed their effects are negligible at most.
With the extensive amount of various vacuum leaks I've had, that statement is no longer true for me. Of course it's a whole different situation when I have pressure going in as well. It shows more easily at idle and low speeds, but it does affect all over on a boosted car.

Lucalare

12-08-2010, 11:53 AM

That raises the question, how do your accessories that run on vacuum(HVAC) work? Do you have a vacuum pump, or what?

jhubbz

12-08-2010, 12:04 PM

I've actually successfully stopped a slight knock by slapping some anti-seize on the spark plugs. It was on my buddy's escort, but still....

[ion] C2

12-08-2010, 12:10 PM

That raises the question, how do your accessories that run on vacuum(HVAC) work? Do you have a vacuum pump, or what?
I'm almost always in vacuum so there's no need, you only boost under heavy throttle. When an N/A car is under heavy throttle, there's hardly any or no vacuum either.

BlueLego

12-08-2010, 07:54 PM

mine did this big time on my alero and then all of a sudden wouldn't go out of first gear. my speedo would also go crazy. turned out to be my vss sensor wires were all messed up right at the connection.

WhiteV6

12-08-2010, 09:00 PM

Sounds like you have a bad ECM, being that is has an issue with the O2 wiring internally. You should be able to do a write entire to the PCM, with your VIN on it.

The stock tune is actually the problem for KR. The engine design itself should not have an issue with cheap fuel, unless the fuel itself is not quality.

Redog

12-08-2010, 09:05 PM

^^ Write entire to the PCM.

I've done that before, at least I think I have, and I still could not change the VIN.

It's worth a shot, because I HATE pulling out the PCM

[ion] C2

12-08-2010, 09:22 PM

Fi-Alero changed his VIN and OS to my car's VIN, so it's definitely possible.

Cliff8928

12-09-2010, 12:05 AM

Redog

12-09-2010, 12:34 AM

OK so what do I do?

My car's a 2000 but the VIN in the PCM is a 2001. It keeps saying "incorrect OS" when I try to do it

AleroB888

12-09-2010, 12:46 AM

In order to change the VIN, you'd need to have either a year/model/engine license if both PCMs are the same in that respect, or just license both VINs. Once you change the VIN, it will come up with a license issue.

What you can do is flash a salvage yard PCM with the file from your car's original PCM ( "write entire" ), then install the clone PCM in the other car. If they are compatible year and BCM, it should work in the other car after relearn process (with the different VIN). You still need the licencing of both PCMs to do that, though.

Other than that situation, the OS has to match the VIN, in HP Tuners afaik. But I have not updated my program in over a year.

Redog

12-09-2010, 12:55 AM

So it looks like my best bet is to swap in the stock PCM and go from there.

However, when I did this before, HPTuners would not let me license the car, even though the VIN was correct on the screen. Don't I have to license it BEFORE doing anything else? When I put in the PCM, it was just like 2 clicks of the mouse and it was licensed :drunk:

Cliff8928

12-09-2010, 01:07 AM

What did their tech support say about your stock PCM?

Redog

12-09-2010, 01:54 AM

They gave me a copy of the Beta v ersion of HPTuners and said try that. I never did becasue the Beta version didn't work with my car, at all :(

WhiteV6

12-09-2010, 03:38 AM

They are constantly updating the beta. You can send me a PCM and I will write your file to it. I have unlimited so that may be why I don't know about its difficulties for flashing multiple PCMs with your own VIN.