I finally gave in and ordered a knock sensor... - 3000GT/Stealth International Message Center

ukyo · 08-04-2009, 09:27 PM

Many of you know my GSX has been pulling timing in the 2K RPM range for the better part of the years I have owned it. I have systematically replaced dozens of things on the car, but it still pulls timing. The one thing I have been reluctant to replace has been the knock sensor. It's not leaking goo so I have been convinced that it is still good.

Well... I finally ran out of options. I ordered the knock sensor from Cherry Hill Mitsu back on 07/26 and it will finally get here tomorrow! I'm really hoping that I can swap it in, turn off the knock sensor ignore in the DSM Link, and actually have a properly running GSX after that. Of course, I have thought that it would be fixed with every other thing I have replaced on it, as well. This is probably the last thing left to replace that the engine uses to determine timing, so I hope it finally does the trick. I guess I'll know this coming weekend. I can't wait!

If it does start acting right I have a set of EVO injectors I can drop in it and actually turn the boost up for the first time in the car's life. That would be fun! Here's to hoping!

ukyo · 08-04-2009, 09:30 PM

I'm going to make a deal with it. If it will run right I will replace the drip molding around the doors and get the spoiler repainted. Parking in the driveway in direct sun all these years have taken a toll on it...

maTT · 08-05-2009, 11:50 PM

hmm, you know I have three friends that are running high 9's in there full interior, a/c, ps, atx daily driver dsm's. Why don't you go that route and kick everyones ass @ trackday! You already have DSM link, that's what they are running

ukyo · 08-06-2009, 07:02 AM

Quote:

Originally Posted by maTT

hmm, you know I have three friends that are running high 9's in there full interior, a/c, ps, atx daily driver dsm's. Why don't you go that route and kick everyones ass @ trackday! You already have DSM link, that's what they are running

Two reasons...

First and foremost, I hate the sound of a free flowing 4 cylinder exhaust. It grates on my soul. I just can't stand it. Second... what have they done to the transmission to keep it alive in the high 9s and daily driven? There is no way my 150K transmission would survive that kind of power.

I'd like for it to run mid to low 13s. That would be ideal for a daily driver for me, but right now I would be happy if I could just get it to stop pulling timing. I'm able to mask it to a degree with the DSM Link, but even with that the car is not running right, it's just running better.

maTT · 08-06-2009, 12:18 PM

With a big enough turbo, you can't hear the exhaust

Those cars sound like jets. They are running gt35's, nos, and meth with a built motor. The trannys are stock. Upgraded torque converter.

ukyo · 08-08-2009, 08:47 PM

I still have the stock converter, but I do have a shift kit and upgraded end clutches...

I got the knock sensor in today. I ended up doing it from under the car, oddly enough. I was able to get it out by only pulling the DP and the plenum stay. So, I button it back up and get it back on the road. I hook up the lappy and disable the DSM Link knock ignore and head to the gas station.

Almost immediately I see the timing take a nose dive (I turned the stock boost guage in to a timing gauge) and the CEL flashes due to timing retard (DSM Link feature). It does this a couple of times on the drive to the gas station, but on the way home nothing. I'm going to leave it as is for the weekend and see if I get a lot of timing retard or if I have actually fixed it. I can only hope this phantom knock plague is over!

NOMIEZVR-4 · 08-08-2009, 08:57 PM

i had a similar problem on my 2g...I went through a lot of crap to try and fix the problem, ending up swaping everything except for the ECU then finally sold the darn thing..lol

I bought it to sell anyways..

ukyo · 08-09-2009, 10:01 AM

Quote:

Originally Posted by NOMIEZVR-4

i had a similar problem on my 2g...I went through a lot of crap to try and fix the problem, ending up swaping everything except for the ECU then finally sold the darn thing..lol

I bought it to sell anyways..

I've swapped the ECU (got a DSM Link), TPS, O² sensor, coolant temp sensor, and now the knock sensor. I can't believe that no one knows how to cure this damn issue. There are a lot of smart peeps in the DSM community, but I have yet to run in to one that knows how to get rid of phantom knock in a 2G.

At least with changing the knock sensor I have seen a change in the way the car acts. Now it only phantom knocks when it's warming up. Once warmed up the timing stays good in the 2K RPM range and the car drives fine. So it looks like the knock sensor was part of my problem... I just don't know what could cause issues with the ECU reading knock only when the car is cold. Maybe the coolant temp sensor I have now is no good? I have no idea where to look now.

The good news is, if it stays the way it is, with the DSM Link knock sensor ignore I can just turn it off up to 3K RPM and it should run better than it did before I replaced the knock sensor. That's what I'm hoping, at least...

One day when I finally sell my DSM I'm really going to miss how easy it is to work on. It's almost fun to work on that car. I guess that is a good thing considering DSM's reputations.

Boost4VR4 · 08-09-2009, 10:21 AM

Quote:

Originally Posted by ukyo

I've swapped the ECU (got a DSM Link), TPS, O² sensor, coolant temp sensor, and now the knock sensor. I can't believe that no one knows how to cure this damn issue. There are a lot of smart peeps in the DSM community, but I have yet to run in to one that knows how to get rid of phantom knock in a 2G.

At least with changing the knock sensor I have seen a change in the way the car acts. Now it only phantom knocks when it's warming up. Once warmed up the timing stays good in the 2K RPM range and the car drives fine. So it looks like the knock sensor was part of my problem... I just don't know what could cause issues with the ECU reading knock only when the car is cold. Maybe the coolant temp sensor I have now is no good? I have no idea where to look now.

The good news is, if it stays the way it is, with the DSM Link knock sensor ignore I can just turn it off up to 3K RPM and it should run better than it did before I replaced the knock sensor. That's what I'm hoping, at least...

One day when I finally sell my DSM I'm really going to miss how easy it is to work on. It's almost fun to work on that car. I guess that is a good thing considering DSM's reputations.

Automatic Timing tensioner is bad, replace it. Had the same thing on my 1G DSM and I replaced the Automatic Timing tensioner and it resolved the timing issue. The DSMLink isn't pulling timing back, as you describe, it's almost as if your timing belt is slackening thus timing is being retarded. I would check that timing tensioner to see if it's providing any tension on the timing belt.

ukyo · 08-09-2009, 11:29 AM

Quote:

Originally Posted by Boost4VR4

Automatic Timing tensioner is bad, replace it. Had the same thing on my 1G DSM and I replaced the Automatic Timing tensioner and it resolved the timing issue. The DSMLink isn't pulling timing back, as you describe, it's almost as if your timing belt is slackening thus timing is being retarded. I would check that timing tensioner to see if it's providing any tension on the timing belt.

The hydraulic tensioner? I've been through 3 of them (original, 60K, and 120K), all OEM, and all had the same result. The car will pull timing only in the 2K - 3K RPM range. The DSM Link is not pulling the timing, the stock ECU is pulling the timing. If I set the ECU to ignore the knock sensor with the DSM Link up to 3K RPM the car does not pull timing.

The belt tension is easy enough to check, so I'll check it. It can't hurt. Thanks for the suggestion.