2.3L ('83-'97) Stalling and I'm too tired to fool around with it.

[oldgeek]

What fresh hell now?

Ok, I know there has been some EGR issues as the CEL has been on a while. But it will turn off while driving. Often at lower speeds I notice it doesn't run smooth. But I've been living with it.

Something new has popped up. To start off in first, I have to barely touch the accelerator and ease off the clutch. To rev up the engine much more than that, it will stall when starting to move after engaging clutch. The engine will still stall when pushing in the clutch after it starts stalling. After getting the truck moving, it runs normal.

Engine codes:

Engine off:
332 (R,M) EGR did not open/respond during test or if memory code, did not open intermittantly – EVR or PFE
335 (O) EGR feedback signal is/was out of range – EVR or PFE

Engine on:
326 (R,M) Pressure Feedback EGR shows low pressure EGR not seating or not seating intermittently – PFE
411 (R) Idle speed system not controlling idle properly (generally idle too high) – ISC

For one thing, it looks like I need to maybe get a new gasket for the EGR. I did replace the DPFE sensor with an aftermarket one a couple years ago, but with that, who knows? It doesn't have a tach, so I don't know what the rpm is at idle, but it always 'felt' high to me, but not having this engine before, I just figured I was wrong.

Can anyone ship me a magic wand? I'm so tired to deal with this.

 

[RonD]

Never touch gas pedal on start up of a fuel injected engine

On cold start the engine should REV then settle at 1,100rpm or so, high idle
This means computer, ECT sensor and IAC Valve are all working
As engine warms up idle should start to drop over 5 min or so, to 750rpms, this means ECT Sensor is working and IAC Valve is not stuck in one position


EGR system is not used until engine is fully warmed up and then only when engine is under a load, accelerating or cruising a highway speeds
However an EGR Valve leak will cause symptoms like you describe
If Exhaust gases are added, from a leak, to an idling engine it will stall or stumble because the air/fuel mix is not high enough to compensate for added exhaust gases like when driving
First pull off the vacuum hose on EGR valve and plug the hose with a screw/bolt or tape so no vacuum leaks
See if that solves the problem, if so replace the EGR Vacuum solenoid/modulator its leak vacuum and opening EGR valve enough to cause issues

If that doesn't change any thing then yes, pull the EGR valve and check that its "valve" can move, its not stuck open, or carbon fouled

The EGR codes are not from EGR gasket

 

[oldgeek]

Thanks Ron.

I guess my capacity for ambiguity is large.

I did not mean when starting the engine. I meant when accelerating from a complete stop.

However, since you didn't ask for an address to ship a magic wand, I'll try disconnecting the EGR in the way you described.

Any recommendations for something to read engine speed? (like I said, I'm so tired and cannot think as to what to search for)

 

[oldgeek]

I have found an old electronic dwell-tach meter. Could I use this on the coil to measure engine speed?

 

[oldgeek]

Hooked the old analog tach meter up. It doesn't have a 4 cylinder scale, just 6 & 8. On the 8 cylinder scale it is showing just a tad under 3000 rpm. I'm guessing with the type of coil, it is around 1400-1500 rpm. It's an analog gauge. The engine speed does not change.

Or would it be 750 rpm? Trying to think on this. An 8 cylinder engine with a single coil. That coil would fire 4 times a revolution. Do the coils on the 2.3 fire every revolution or every 2 revolutions?

 

[RonD]

Each spark plug fires once per RPM on your Waste spark system, ignore dual spark plugs
Each spark plug fires on compression stroke TDC and then again on exhaust stroke TDC, exhaust spark is "wasted", hence the name Waste Spark ignition

Exact RPMs wasn't the point, is the idle higher when cold and then drops lower as engine warms up over then next 5min or so?

Another test
After engine is warmed up and idling
Unplug the 2 wire connector on IAC Valve
Idle should drop or engine may even stall, if neither happens you have a vacuum leak and that can cause your stumble on acceleration
But EGR Valve is still best bet for that as its also a vacuum leak if EGR valve is not closing tight