have you checked your fuel pressure? make sure it stays there too

I bought a fuel pressure gauge and and hooked it up to the fuel rail valve.
This was my first time performing such test, so I'm no expert, but I read the instructions on how to use it.

I hooked up the guage to the fuel rail, turn the ignition key to on and got a read of just over 50 psi of pressure.
With the engine running, the pressure is still the same 50 psi.

I even had the engine stall on me while the pressure guage was on the fuel rail, same reading 50 psi.

In other words, my fuel pressure gauge reads 50 psi even as the engine stalls.

I'm not certain if my results of the test eliminates the fuel pressure regulator from being the cause of my stall, but I'm assuming it does.

Btw, with the car running, when I take the vacuum hose off the top of the fuel regulator, the fuel pressure gauge jump a few degrees up as I've read it should.

Under the results of my fuel pressure test, I've come to the conclusion that both my fuel pump and fuel regulator are fine.



Am I missing something I did'nt follow through on my fuel pressure test??

Do my results eliminate the fuel pressure regulator being the cause for my stalling?

pressure sounds fine, got to be something else

Bought and Installed that 2nd crankshaft sensor, unfortunately the engine is still stalling.

Maybe IAC next???? I had ruled the IAC out because the engine was stalling when I was driving 35+ mph. But I wonder now that the stall at those speeds may have come while I was coasting and thus the throttle plate may have been nearly closed.


MAF maybe?

Ok, I've bounced my stalling problem to another automotive troubleshooting site and it was suggested to disconnect my IAC to see if the engine still stalled with the IAC disconnected.

I did the same with the MAF sensor.

The engine idled fine with the IAC disconnected, but then of course after awhile it stalled.

I did the same with the MAF and again after awhile the engine stalled.

I was told that this procedure of having my car stall while those sensor'* harness was disconnected, eliminates those sensors from being my problem.
Anybody out here disagree with that????

Allright guys, I'd appreciate a little help here.

I've been doing a little searching and reading and come about that a bad coolant sensor or a bad air temp sensor can cause hard starting and stalling on an engine.

I've measured the resistance on these sensors and here'* what I came up with.......

The coolant sensor....with the car sitting overnight and the outside ambient temperature about 75 degrees, I put my ohmeter on the 20k scale and the coolant sensor read 3.20.

With the engine warmed to about 190+ degrees, the coolant sensor read 0.22

The air temp sensor read 1.90 with the engine not warmed.
With the engine running and the engine warm to close to 190 degrees the ohmeter reading was 2.02


Are these readings within normal range or are they off????




The reason why I came to suspect these sensors is that I've noticed the last few days that my car is much more difficult to start at night with the ambient outside temp lower.

During the say, particularly if the temp outside is close to 80 degrees, I can start the engine with a few cranking attempts and drive a couple of miles to the store or post office without it stalling on my way there or coming back.
......but if I make my trip at night when the sun is down and the outside temp is under 70 degrees, a 2 mile trip will have my engine stalling several times, sometimes even 5 or 6 times during a 2 mile trip.

Your comments would be appreciated.

Well, the Impala had been sitting nearly 4 months.

After thoroughly checking for different things that could cause the problem I got tired of seeing it sit there. I made up my mind to have it towed to a Chevy dealership for them to figure it out.
Taking it to a dealership is always an absolute last resort as I just dont trust they will be truthful with me when they diagnose it.

Anyhow, I decided to to one last check of all the fuses and probe them for voltage.
Doing this I found the problem.

I probed the fuse at the panel inside the Impala labeled "pcm/bcm/clstr" and found it to be reading much less than the battery voltage.
I was actually using a probe light, and when I probed that fuse the light on my probe lit very dim.
Every fuse on the fuse box panel lit bright, but the "pcm/bcm/clstr" did not.

Turning the key on the ignition switch on and off several times, I found that the circuit I was probing would light up proper (12 volts) in some instances.

When that circuit would read 12 volts the car would start right up.
Leaving the test probe in the circuit, the car would shut off after a few seconds and the circuit would simutaneously drop below 12 volts.


I then did a google search and found out that if the "pcm/bcm/clstr" circuit was reading below battery voltage, the probable cause would be a bad ignition switch.

I did'nt change the ignition switch however.
Instead I ran a wire from a good 12 volt source thats holds current only with the key positioned at on, and ran that wire to the "pcm/bcm/clstr" circuit, and presto problem solved.

My Impala is up and running with no problem.

I would never have thought that the ignition swith would be the problem because everything else in the car was working. I had probed for 12 volts at the ignition module and it was fine.
The only problem was that the care was stalling.

Turns out that because there is a wire coming from the ignition switch thats intermittently not holding proper voltage, the PCM and BCM were not getting the 12 volts from the ignition switch and causing the car to stall.


It took 4 months of seeing the car sit, but I can say I'm a happy man having fixed it myself.

Those con boys at the Chevy dealership can kiss my ***!

lol. thanks for posting your fix