Stuttering DSM

[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

[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

[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 ~