2.3L ('02-'11) will not idle

[maverick9611]

2002 ranger 2.3L

I have mid range, top end power. super unstable on botton end
so far i have changed out
pcv valve and hose.
fuel filter
idle air control valve
mas sensor
i did findvacuum line disconnected it plugs into some valve right next to firewall directly inline with intake manifold.
has me baffled

 

[maverick9611]

changed out upstream o2 sensor, no change. will try egr valve next

 

[Dirtman]

Did you plug the vacuum line back in? Check for other vacuum leaks? Stop replacing random parts!

 

[alwaysFlOoReD]

I've never worked on the 2.3 but the vacuum line that was unplugged sounds like it for the FPR = Fuel Pressure Regulator. If the diaphragm of the FPR is ruptured then there will be excess fuel getting into the combustion chambers. Its a cheap part, change it.

 

[Dirtman]

There's no fuel pressure regulator on an 02 2.3, it's a returnless system. The vac line he's referring to could be the IMRC solenoid or pulse dampener.

The IMRC (intake manifold runner control) system is prone to issues especially vacuum leaks and theres a plug on the intake manifold that is known to simply fall out. The fuel pulse dampener is not actually vacuum controlled even though there is a vac hose on it. The vacuum hose is just there in case of catastrophic failure the fuel will be dumped back into the engine. The dampner could fail and you wouldn't really notice any issues, if it leaks you'd get a rich code, with the line detached however you'd obviously get a lean code.

 

[maverick9611]

Did you plug the vacuum line back in? Check for other vacuum leaks? Stop replacing random parts!

of course i plugged it back in

 

[Dirtman]

of course i plugged it back in

You never know.

I'd start by doing a complete vacuum leak test. YouTube has plenty of good videos for various methods. First is just to start with a visual inspection though. Your symptoms sound like a vac leak. Under mile-high throttle there is less engine vacuum so leaks become less of a problem then they do at idle and low rpm.

 

[maverick9611]

ok, sounds good. where is this plug on intake that i need to look for? is their a map of vacuum lines for the 2.3?

 

[Dirtman]

I'll see if I can take a pic of where the plug is. As for the vac lines it's fairly simple. Egr is not vacuum operated and only one line to the hvac controls. Brake booster, fuel dampner, pcv valve, and imrc solenoid are all on one fitting at the rear of the head. Evap purge solenoid is on the driver side fender, fresh air side of the pcv is on the valve cover, and hvac line is on the throttle body. I'll see if I can find the schematic.

 

[maverick9611]

i found one on autozone.

Repair Guides

AutoZone Repair Guide for your Emission Controls Vacuum Diagrams Vacuum Diagrams

www.autozone.com

 

[Dirtman]

None of that is right... even a little bit...

I'm actually very confused by that because none of those engines apear to even be ranger engines... the 2.3 diagram is completely wrong either way. It's not even correct for the older lima 2.3.

 

[maverick9611]

bummers

 

[maverick9611]

did you find that pic of the plug?

 

[maverick9611]

stumbled onto this vid. sounds similar to my problem

 

[maverick9611]

gettin ready for compression test, found cylinder#1 spark plug well full of oil. this could be my misfire. if compression test passes, i will change valve cover gasket to stop oil leak.