Hi All! This is my first ford, actually my first truck. I bought is as a semi-working project. I have most of my problems straightened out but im having some difficulty with my idling. My problem is that when I start the truck it immediately fires up and then stalls right out. Sometimes i get lucky and it idle hunts a few times but eventually will die. I keep tapping the throttle as the rpms drop and i can keep it running till its warm. When its cold it hesitates a tiny bit, but that could be because i dont want to give too much gas, stops hesitating after maybe 1 minute. Then it will idle decently for maybe 5 sec, then the rpms drop again and it hunts/stalls. Once it finally warms up it seems to idle better, but not spectacular. Idles around 900 - 1000 rpms. It has never stalled when cold. Also anything above 1500 rpms seems to run perfectly, runs strong and sounds good. I tried a new map sensor and it didn't change anything. Also installed a new tps and defiantly didn't get better. I checked my fuel pressure: 38 psi engine off, 36-40 while idling with vac hose attached. Pressure goes up a bit when when vac line is disconnected. Here some more background info:
-I replaced the plugs, gap was good
-replaced the ignition module
-timing is btdc about 12 degrees
-wires look good, were replaced by po
-no CEL
-replaced temp sensor for gauge cluster
-new battery
-new starter solenoid
-exhaust (glass pack and pace setter shorty headers)

things that don't work:
-speed sensor doesnt work, no speed on spedo
-no egr or emissions pump, do have the egr valve hooked up to prevent cel but its just sitting idle on the wheel well
-temp is always cold, gauge goes up to cold line of the normal operating temp marking on gauge when engine is warm, i think the gauge is messed up here, engine seems to get warm and i do feel warm air coming from blower
-aft tank seems to leak gas, maybe the the o-rings on the fuel lines but i haven't got to that yet

Interesting observations:
-Truck does not throw CEL when i unplug o2 sensor
-when i unplug the vac line from the fuel pressure reg, truck runs almost perfect idling and when revving.
-there is vac, I put my finger on the line there is some good suction, don't have a gauge though.
-today while driving home from work, truck started to idle at 2800 rpms maybe 7 minutes into my trip. Then at 2100 rpms, then 1900 rpms, all within i mile. i shut her down and restarted 5 mins later and it seems to idel fine at about 900 rpms, sometimes it idles at 1100rpms usually after 20+ minutes of driving and only sometimes.
-I can hear the ICV open up and allow in air when its idle hunting, rpms shoot up to 1500 or so then drop to 500 where it almost stalls and repeat
-I switched from FWD to AFT gas tanks while driving and 1 minute later it stalled out on me while driving at 2000 rpms (not sure if i should be doing that), I pulled over, cranked it and nothing. I switched to FWD tank and it started right up and no further problem like that.

If anyone has any ideas of what this can be or more things i should be checking I would defiantly appreciate it. Its not my DD so I can toy around with it a bit without having to drive it the next day. thanks to anyone for having the patience to read this entire thing.

 

Check codes first always. They will often tell you whats wrong.

Did you set timing with the "Spout" disconnected?

The fuel pressure is a bit low, change filter?

Is the pressure good form both tanks?

I suppose you checked all around for vacuum leaks?

Again check codes rather than replacing parts. Then check the sensor or actuator before replacing it if you get a code.

 

spout was disconnected when I set the timing. timing was different and bouncing around a bit with the spout reconnected, so i guess the dist. works.

I don't have a CEL atm (yes the lamp works), ill check for any codes in the background. Ill post when I pull any codes.

filter was just replaced by PO, I gave the lowest number, seemed to creep up just a bit past what i posted, maybe 2-3 psi. PSI for front vs rear was maybe 1 psi difference.

I checked for Vac leaks, im not to familiar with the engine but i found all hoses connected and no open areas in the plenum. Ill see if i can find a Vac diagram and double check.

 

I reset the codes and took the truck for a spin. I have two codes 67 and 85
Neutral safety switch and canister purge valve.

I don't think I have a purge valve installed in the truck, I believe the po removed it.

However I did notice that the truck runs and idels almost perfectly with a massive vac leak. I forgot to attach the cruise control vac hookup. The minute i attached it it stalled out on the spot. Maybe since all the evap stuff is plugged up the massive vac leak compensated for it? I'm not to familiar with the evap system in this car. Any other ideas here?

 

To close this thread, the problem ended up being an open connection between the tps harness and tps connector. Also the throttle screw was set out of range of the tps. An ecu reset and some driving seems to have solved all the issues above.

 

Thanks for the feedback!