stuttering issues

[hoveringuy]

A MAF problem could do that. Doesn't sound like an air leak so much.

[loonibab325i]

ok so i changed the o2 sensor and that didn't work out, i kinda got frustrated and took off the intake manifold and decided to just re-do all the vac lining touch up the wiring a bit etc etc make sure everything is clean..well after that the problem went away.. and uh.. 3 days of perfect driving it dies on me, wont start, wont send fuel or spark. i'm really thinking it could be the crank positioning sensor, any ideas? I need a freaking code reader!

[SamE30e]

Crank position sensor could do it, it would explain no fuel or spark. The car should run without a cam sensor, just shit.

Just pull the plug on the o2 sensor and check the resistance, terminals 1-2 should be 480ohms. Could be bad wiring on on the actual connection too.

[BigD]

Add another vote for the crank sensor. Sounds like it's gimping out or you have a broken wire/bad connection. If it's not new (which it should be, cause you got all new sensors while your engine was out... right?), replace it.

[loonibab325i]

So yesterday i go to plug in a peak code scanner and it didn't work, i'm freaking stumped!?

1) my check engine light doesn't work, so i can't do the stomp test, and 2) my diagnostic port doesn't seem to work? I have the akg motorsport wiring harness, i have no idea if they didn't support the check engine function? Any ideas?

[hoveringuy]

Crank position sensor could do it, it would explain no fuel or spark. The car should run without a cam sensor, just shit.

Just pull the plug on the o2 sensor and check the resistance, terminals 1-2 should be 480ohms. Could be bad wiring on on the actual connection too.

We don't know for sure that it's getting/not getting spark when it stumbles. I love using 12v LED's to diagnose stuff like this... hook one up to the input of one of your coil packs and +12v. Tape the LED to one of your wiper arms. If it stumbles when the LED is still firing it's got nothing to do with spark.

You can check the crank position sensor with an ohm meter. They're fairly robust but you never know. I would check the CPS resistance at the DME plug itself to preclude any wiring issues. Do you have the DME plug pinout? It's very useful. You can check you throttle potentiometer the same way.

[FredK]

I love using 12v LED's to diagnose stuff like this... hook one up to the input of one of your coil packs and +12v. Tape the LED to one of your wiper arms.

Ha, that's exactly what I did when I was trying to diagnose a no-start condition on one of my cars! It is an excellent, inexpensive diagnostic tool.

[hoveringuy]

Ha, that's exactly what I did when I was trying to diagnose a no-start condition on one of my cars! It is an excellent, inexpensive diagnostic tool.

I've had 2 or 3 LED's taped to my wiper arm at times. One for DISA, one for VANOS, etc. Then I have a circuit board with more blinking LED's on my passenger seat.

I drive on base and the guard thinks I'm a terrorist. I can't tell him it's an Improvised Electronic Device, he'd shoot me!

[jrdeamicis]

Ok, trust me on this one. You need to check your Crank and Cam position sensors.

If you have access to an oscilloscope put it on the crank position sensor and look for whats going on.

Both of those sensors will create serious shuddering problems.

[loonibab325i]

ok, so i just got a new crank positioning sensor but still no luck.. ERRRRRRR, there goes $ down the drain.

i'm all out of freaking ideas.

[e30polak]

Cam sensor?

[hoveringuy]

Maf

[SamE30e]

Cam sensor?

It would run without it I think, just very shitty.

[dashboardmonkey]

Try swapping your DME with one out of a running car? Just an idea.

[e30polak]

It would run without it I think, just very shitty.

My cam sensor problem caused delayed vanos engagement, causing the car to hesitate in and out of it between 3k-3.5k.