2G Bad sensor?

[Dsm13]

Car likes to spudder and sometimes stall most often when put into drive and when coming to a stop. Sometimes it'll also spudder when giving gas from a dead stop and it'll shift hard in higher gears. Alot stuff online meantions idle air, fuel filter, cam shaft, mass air flow, or o2. It seems like there just throwing shit out especially sense I don't think I have a mass air flow sensor cause I don't see any wires near the air filter. Any suggestions?

 

[92AWDHX40]

Do you have any codes.

 

[ThunderChild]

Do you have any codes.

Step one for sure

If no codes, id start looking at ECT and TPS sensors, as well as do a BLT.

What mods are done to the car?

 

[dave_nz]

Check the codes first. What sort of maintenance has been done on the car? I'd be checking the fuel filter first. Wouldn't hurt to pull the plugs and have a look as well.

 

[Chumpaumpalumpa]

Boost leak test. A LOT of DSMers have posted stuff like this when they just had boost/vacuum leaks. Could be the tune as well. Do you have a WB gauge. I'm 5 spd but my tune is lean rn in the idle-1200RPM range and it causes a stutter or bog. Usually a stutter. When I say lean I mean 16.8+

 

[Dsm13]

No error codes. I checked the ignition wires. Very clean.

 

[DogWhistle]

If you don't have a sensor plugged in on the little black box next to the air cleaner, you either: a) Don't have a MAF and you are running Speed Density, or b) The previous owner had tuning problems and ran with the MAF unplugged, so that the car would stay in Open Loop all the time. Ask me how I know

Open Loop (not using other sensor's data), often results in running too rich, which is what it sounds like yours is doing.

You've got to find the MAF plug and check the voltage to it, to see if it's active.

 

[PlanZero]

This is a 420a? Don't bother looking for that maf plug. If you didn't change the fuel filter and plugs when you got the car do it now.

 

[ThunderChild]

Ah dang. Missed that n/t part.

I'd be looking at the map sensor and it's port (420a motors get alot of carbon buildup) or the crank/cam sensors. If the crank sensor is oil contaminated it will cause spark issues.
Next start looking at the coil pack

 

[Dsm13]

I tried the coils and crank sensor. No change. Map Sensor looks clean. Oh....

And now the RPMs are dropping when hitting bumps as well as being stopped and hitting high speeds. Another thing about the Map Sensor is that the car won't start when it's unplugged. Is that normal? I thought that if it was unplugged it was supposded to run with default settings or some shit like that.

 

[ThunderChild]

sounds like you might have some loose wiring. its affecting your fuel or timing, more than likely timing related. when the car is idling, you can try tapping on the coil or its connector to see if it affects the idle.

 

[Dsm13]

Fixed. Took it to mechanic. Turns out there were wires from a wire brush stuck in-between the cam sensor and its contact point.