Running rich

[muddacres]

1987 ranger 2.9 5speed. running rich stalling. tried map sensor, air charge sensor, oxygen sensor and still runs same.
Jim

 

[adsm08]

You probably have a ruptured pressure regulator. Pull the little vacuum line off the fuel rail and check for fuel in it.

Postin' from teh Galaxy

 

[muddacres]

I looked and no gas in there. I was hoping.
Thanks
Jim

 

[RonD]

Does it run OK cold and only start running poorly warm?

Could be ECT sensor
http://oldfuelinjection.com/?p=28

ECT sensor is the "choke" on fuel injected engines, these don't fail often but if they do your engine will act like it is running choked after it warms up.

There are two coolant temp sensors on the engine
The 2 wire ECT sensor, used by the computer
The 1 wire temp sender, used by the temp gauge on dash board

 

[jhammel85]

Even though theres no fuel in the vac line, It's still worth checking your fuel pressure. When my regulator went, It did the same as yours and I had no fuel in the vac line. The only way I found the issue was because I checked the fuel pressure and it was off the charts!

 

[amarino23]

Also besides fuel reg check. Fire the truck up and spray starting fluid over you vacuum lines and where the intake bolts to the head (area) if there's a vacuum leak it will dip in rpm and then rev its very noticeable! and don't worry it wont light on fire, done it a thousand time but of course be cautious.

 

[muddacres]

I tried starting fluid before post. My son said he changed fuel reg. I need to check the wiring. I thinking a match will fix it. LOL thanks for your help guys.
Jim

 

[RonD]

I tried starting fluid before post. My son said he changed fuel reg. I need to check the wiring. I thinking a match will fix it. LOL thanks for your help guys.
Jim

Yup, gallon of gas and a match make for a nice Insurance fire
Reading like your halfway there with the "running rich"

 

[muddacres]

LOL That would be good if it had fire on it.

 

[RonD]

Have you tried listening to the injectors with engine idling, I have used a small diameter hose as a stethoscope, just listen for the steady click, click, click, no odd clicks like a stuck injector.

You can also OHM injectors, use ohm meters lowest setting, each should be about 14ohms, 11-18ohms is the acceptable range.

Also when you pulled off the vacuum line on the Fuel pressure regulator(FPR) did the idle on the engine go up, it should with a vacuum leak like that.
Maybe vacuum is plugged up so not opening FPR as it should causing high fuel pressure and flooding.
The Fuel pressure the computer expects at the rail is 30-40psi, it opens injectors for a specific length of time based on that pressure, if pressure is 50psi then injectors are open too long so rich condition.


Rich means more fuel than air in the mix, so why not add some more air, run a vacuum leak on purpose, see if conditions change.

Also make sure PCV valve is working, that is extra "air" the computer counts on being there.