Friends,

My truck started stalling/dying while i'm driving but in neutral 4 days ago. It does it not matter how fast i'm going. In the last 4 days I've stalled about 15 times with the engine running in neutral. I can be going 50 mph down a hill or 10 mph about to turn. It happens.

I've noticed that it only happens when my clutch is in. Since its manual, that's a lot of the time. If i coast with the stick disengaged but not pressing in the clutch, then it does not stall.

Also my engine and truck literally shakes when i engage my clutch about half the time. I can feel it wanting to stall sometimes as i press in the clutch, so ill gas just a little in neutral and it won't stall.

I have also tested this specifically. If im coming up to a light in neutral with the clutch disengaged, then press i'll it (although i was already in neutral. im pressing just to test the theory) the truck will shake, and once it did stall just because of the clutch engagement.

I'm thinking its either something to do with o2 levels in neutral, or fuel injection?

I got emissions done about a month ago, so my codes have been read recently. I dunno.

Please help!

 

Fuel injected engines can't use an idle screw, they have no jets to add more fuel when adding more air, so engine would run too lean when idle is increased using a screw on the throttle plate.

So they all use an IAC(idle air control) Valve controlled by the computer......which also controls the fuel.

When a fuel injected engine is started cold(without touching gas pedal) the RPMs should go up to above 1,500, then drop down to about 1,100-1,200.
Thats the computer opening the IAC Valve all the way, then closing it a bit to set cold idle, cold idle is based on engine temp, colder engine higher idle, this is "choke mode", a computer routine that runs high idle, advanced spark timing and richer fuel mix.

If the above is not happening then you have a problem, most likely IAC valve needs to be cleaned or replaced.
Warm engine idle should be 650-750rpms for manual trans vehicle.


On '95 and newer engines/computers(OBDII) with manual transmission there is a fuel saving method that causes computer to hold idle at or just above 1,000 RPMs when speedometer is above 5mph and clutch pedal is in.
When clutch pedal is in and you are 0-4mph then idle should be 700 warm or 1,100 cold


O2 sensors are not used at idle, and stalling would not be a symptom of O2 issues.
Fuel injector issues cause misfires or loss of power at higher RPMs(not enough fuel)

And these would also cause CEL(check engine light) to come on

TPS(throttle position sensor) on the 2.3l/2.5l engines can cause odd ball stalling.
They can be tested with volt meter.

 

how long since you replaced the fuel filter

 

Did you ever figure out what the problem was? I'm having the exact same issue now.