Stuttering DSM

[ESchwanz]

my DSM has seemed to developed a stutter.... any Ideas what it is??
Check out the video --->http://www.youtube.com/watch?v=Q6nhaT-wRxw
Any help would be great!!
Thanks!

[Wizard]

Check and clean power transistor connection, tps and also clean and check all your grounds. Especially the one near the ECU.

Wiz

pills11.com )

[Dizmm]

i cant really tell anything form the video but have you checked the basic things. Spark plugs and wires???

[JET]

I would say it is plugs or wires also. It happens all the time in DSM's.

[Dizmm]

Originally Posted by JET

I would say it is plugs or wires also.

I second that

[ESchwanz]

Ok, I'll check those things. I'm going to re ground the coil packs tomorrow & check the plugs, & check for an exhaust leak, the plug wires look good, no cracks, ect.. I'm Just really confused at why it doing it constantly. sometimes It will make the stutter and hold the stutter even after dropping the RPM's & while revving. once its started the stutter it seems like it will only stop if the RPM needle hits 0, then it will drop it. tonight to get home I had to keep turning the key of the car to off for a sec so the needle would touch 0 to get the stutter to stop. sometimes it wont do it for a long time. I drove almost 40 miles after picking the car up before it did it the first time. hmmm ... MAF?? SAFC??? Injector?? I'm too new to this engine to really know what it is, but those are thing i thought it could be. :~

[Wizard]

I would say plugs and wires, but gave the benefit of the doubt. And it seems to be more random than load/boost related. Bad/worn plugs and/or wires would give a constant under load/upper rpm miss/studder.

Plus, according to the video the system goes lean during the studder. Which tells me it's not spark related...but probably more towards fuel and or fuel control.

Wiz

[scheides]

It is really hard to tell exactly what the problem is in the video, but I had an issue very similar to what you seem to be describing on my 2G. I could cruise just fine, but if I'd do any part-throttle acceleration the car would just start making that noise you're describing, like misfiring really bad. I spent a LOT of time and money trying to figure it out, and in the end all that needed to be done was reset the ECU and it would go away for a few months, then come back randomly. I never got a chance to replace the ECU and see if it would go away permanently.

[ESchwanz]

Originally Posted by scheides

It is really hard to tell exactly what the problem is in the video, but I had an issue very similar to what you seem to be describing on my 2G. I could cruise just fine, but if I'd do any part-throttle acceleration the car would just start making that noise you're describing, like misfiring really bad. I spent a LOT of time and money trying to figure it out, and in the end all that needed to be done was reset the ECU and it would go away for a few months, then come back randomly. I never got a chance to replace the ECU and see if it would go away permanently.

To reset the ECU I gotta disconnect the battery, correct? will this erase the map info on the SAFC II?

Will putting in a DSM link fix that or do I need a AEM, or hYdra EMS?

[Wizard]

Its very rare for a 2g ECU to go bad. More than likely it was a bad connection somewhere. But, the ECU is a computer, like your home computer and a cell phone. Sometimes it justs needs a reboot to readjust things and start over.

Sounds like you have some ideas to try...let us know what you find.

PS: Do one fix at a time or you'll never know what fixed it. That way you know where to start next time or can share your experiance with others when they have the same problem.

Wiz

pills11.com )

[Pushit2.0]

Originally Posted by Wizard

... Plus, according to the video the system goes lean during the studder. Which tells me it's not spark related...but probably more towards fuel and or fuel control....

A 02 sensor only reads air, if a cylinder miss fires there is a lot of air that comes out, because it did not burn the fuel. So a wideband will read this as lean, or a narrow band might catch it, but the sample rate of a data logger or scanner is so slow it might not catch it.
To better help this guy we need a full mods list, and whats wired up on the interior. Check to make sure the MAS, coil pack, PTU, cam/crank sensors, o2 sensor, injectors all have a good connection. Then look at the ECU wiring, I have seen people use the ECU sensor ground for things like gauges, WB o2s etc, this will burn up a small part of the board and cause problems.

~John

[tpunx99GSX]

My car did a similar thing, but i had dsmlink and all i had to do to fix it was disable the Random Cylinder Misfire box and it fixed the problem.
Its wierd that your A/F jumps up each time it happens.

[JET]

A/F always jumps during misfire, for the reason John said. It will read lean.

[ESchwanz]

Originally Posted by Pushit2.0

A 02 sensor only reads air, if a cylinder miss fires there is a lot of air that comes out, because it did not burn the fuel. So a wideband will read this as lean, or a narrow band might catch it, but the sample rate of a data logger or scanner is so slow it might not catch it.
To better help this guy we need a full mods list, and whats wired up on the interior. Check to make sure the MAS, coil pack, PTU, cam/crank sensors, o2 sensor, injectors all have a good connection. Then look at the ECU wiring, I have seen people use the ECU sensor ground for things like gauges, WB o2s etc, this will burn up a small part of the board and cause problems.

~John

Thanks John for the info!! I need to learn as much as possible about the 6 bolt.
I'm still waiting for all the paperwork from the old owner (he's got a ton!)for all the supporting mods... but I just have a few odd questions.
When the owner before me put the 6 bolt would they have had to change ECU out at that time, and would that cause the OBD II to not function properly? I hooked up my OBD II Reader and all I got was ERR 1, or error1 cant remember. or is this the cause of my problem ... fried ECU?? ... Hmm I cant wait to fix this & discover its full potential. Think I might have a fuel problem maybe also. I smell gas in the car. I'm gonna check his seal on the top of the tank under the back seat this weekend. Cant trust anyone else job other than my own. coud this be the the stutter problem. I think the Fuel pressure guage on the fuel rail is broken too. What is the fuel pressure need to be at, because I think the needle on mine is stuck at 100 PSI.
Oh and I really don't trust his job on the gas tank, because I ran out of gas the other day! I should have known by the trip meter but I wasn't thinking... I was going to work. lol!! The reason i thought i still had gas was because the needle was stuck at half a tank DOH!! So once I get the papers I'll update.

Eschwanz ~

[JET]

Sounds like he bent the arm for the fuel sender in the tank. That is pretty easy to do if you force the fuel pump back in. There is no ECU change to put a 6 bolt in, but you do need to do some modifications to do it. Any idea if he put a new CAS in? And yes, at idle you should be around 35 psi for fuel pressure.

[ESchwanz]

Originally Posted by JET

Sounds like he bent the arm for the fuel sender in the tank. That is pretty easy to do if you force the fuel pump back in. There is no ECU change to put a 6 bolt in, but you do need to do some modifications to do it. Any idea if he put a new CAS in? And yes, at idle you should be around 35 psi for fuel pressure.

hmmm...

[scheides]

Dude, is this a black 97 GSX? How long have you owned it?

Here I am giving you advice about my old car and I think that you have it! Woowoo! I was just missing that car today!!! It had the fuel pressure gauge mounted on the fuel rail, and I recognize that CAS and the one wire that swanny helped me patch together on its plug. And the wideband gauge in the dash, its a PLX right? Also an ebay strut tower bar?

Just pull the power to the negative terminal of the ECU for a minute or two, plug it back in, and this will go away, just like I said before

Where do you live, can you come take me for a ride in my old car?

[scheides]

PS why didn't you post in the new members section damn it! I could have helped you with this already The gas tank arm I think must be stuck in place because the fuel pump assy kept coming loose after a few weeks or months of driving, until I finally got it to stay (stupid 2G assy sucks!)

[ESchwanz]

Originally Posted by scheides

Dude, is this a black 97 GSX? How long have you owned it?

Here I am giving you advice about my old car and I think that you have it! Woowoo! I was just missing that car today!!! It had the fuel pressure gauge mounted on the fuel rail, and I recognize that CAS and the one wire that swanny helped me patch together on its plug. And the wideband gauge in the dash, its a PLX right? Also an ebay strut tower bar?

Just pull the power to the negative terminal of the ECU for a minute or two, plug it back in, and this will go away, just like I said before

Where do you live, can you come take me for a ride in my old car?

Yep, PLX. Should I put in my AEM or is it just as good? & does anyone local sell the fuel pressure gauge, because the old one is stuck or the regulator is really bad! 100+ psi. I think Ill get the DSM Link soon ..... That should fix it , correct? The stutter is something to do with the CAS &/or the AFC II conflicting possibly or with ECU?
Oh and I'm in Shakopee but work in Dayton, & I carpool with someone from MPLS. would love to hear all what you did to it. Once I clean it up a bit more and get rid of the gas smell I'll let ya ride in it if ya want.

Originally Posted by scheides

PS why didn't you post in the new members section damn it! I could have helped you with this already The gas tank arm I think must be stuck in place because the fuel pump assy kept coming loose after a few weeks or months of driving, until I finally got it to stay (stupid 2G assy sucks!)

Oh & Ive been a member for a while just not very active because my old car was just a GS 420A and well..... . I also just got the car last Friday, from probably the person who bought it from you.

[JET]

The PLX is better than the AEM, keep it. Those guages are everywhere, probably even Checker or Advance. If not, MAS will have them.