Ok guys I'm stumped help me pls
 

(95 Ranger 3.0) just rebuilt. It starts right up, but when its idling the rpms go and down up and down then struggles a d then cuts off after 10 secs of struggling. I checked the vacuum lines (everything correct). It's doesn't have any o2 sensors in it right now (waiting on them, just ordered them). Exhaust is just manifold and Y pipe. Haven't installed anything after that yet. Could it be the Exhaust and o2 sensors or maybe something else. Starts right up though.

No, O2 sensors wouldn't be the issue they are not used until engine coolant is warmed up above 140degF

Its most likely a fuel or fuel delivery issue

How old is the gas in the tank?
Gasoline can only lasts 3 to 4 months
When was fuel filter last changed?

Spray fuel into the engine to see if you can keep it running

Check if there is fuel pressure after one key on then key off, don't try to start
Then check if there is fuel pressure after the stall

Gas is brand new and so is the fuel filter and the injectors ( besides sitting for a year) are all new

So I just ran the code reader on it and only codes coming up was the 02 sensors, I didn't have enough time to get a fuel pressure tester. I'll have to do it tomorrow. Everything with the fuel system is new (fuel sending unit and pump, injectors, relay, filter, regulator)

New means NEVER EVER TESTED now-a-days, so heads up on any "new part"

What was exact code number, there are at least 6 O2 codes per O2 sensor, but not your issue in any case

Do the 50/50 test, i.e. spray fuel into the engine to see if you can keep it running longer
That will tell you if its a fuel or spark issue, 50/50 test

The codes were p0135, p0155.

Into the manifold?

Yes, same as injectors do
Pull off the large air tube from intake, try to start engine, if it starts then spray fuel(gasoline, ether, carb cleaner, ect....) into intake to see if it will stay running

3.0ls sometimes won't start or stay running if MAF sensor has no air flow passing it, so if you didn't have that large air tube installed then install it and see if engine stays running



P0135 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0155 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
These are Heater codes because O2s are unplugged

You don't have, P0141 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2),because its most likely still plugged in, downstream O2,after Cat Converter

Right now I don't have any o2 sensor at all not even the old ones install, my exhaust ends at the y pipe. So those codes are because I don't have any o2 sensors plugged in. But I'll try the fuel when I get home I can keep the engine by pumping the gas pedal when it tries to die out.. this truck is like a Rubix cube.

If opening the throttle more keeps it running longer then engine may be Flooding Out
On fuel injection there is no more "gas pedal", i.e. pumping the "gas pedal" doesn't add more fuel like in a Carb, it just adds more AIR, so its an "air pedal" now, lol

Well not pumping it really just hitting the gas pedal everytime is tries to die on me.

So adding more air helps, start there, may be too much fuel?

So how do I start there ?

Gasoline engine just need 3 things to start and run
Compression, above 120psi, 150psi is average
Spark, at the right time
Fuel, in correct mix with air, 14.7:1

We will ASSUME at least some cylinders have enough compression, since it does start
Which leave you with, Spark at the right time
1995 3.0l uses a 3 coil Coil Pack, not 6 coils, 3 coils
So it has an odd coil pack wiring setup
3 4
2 6
1 5
OR
4 6 5
3 2 1

In either orientation, 3/4, 2/6, 1/5 are Matched Pairs they share a coil in the coil pack

Ford V6 cylinders are numbered this way
3 6
2 5
1 4
Front

So follow each spark plug wire from the coil pack to its correct cylinder, then DO IT AGAIN

Fuel
1995 3.0l runs 35psi fuel pressure
It has a Fuel Pressure Regulator(FPR) on the engine
FPR has a Fuel hose attached AND a vacuum hose, check that vacuum hose for gasoline, if FPR leaks then raw fuel gets sucked into the engine, causing Flooded condition

You can also pull out all 6 spark plugs
Then crank over the engine and watch for HIGH fuel ejection from a cylinder, this would mean a leaking injector in that cylinder, I would disable coil pack, unplug it's 4 wire connector for the test,I doubt it could ignite the liquid fuel but better safe than sorry, lol
I would do a compression test at this time since all 6 spark plugs are out, just to be sure everything got put back together OK, take it off the table so no longer an ASSUMPTION

That would take care of Flooded engine theory

Next would be to add fuel manually thru the intake
Spray in fuel to see if LACK of fuel is the issue

Thanks man I really appreciate it you been a great help. Looks like I have a longer "to do" list now

This is what is sounds like I WASNT hitting the gas pedal or anything I was just letting it idle after starting it

Unplug the IAC Valves 2 wires, so computer control of idle is offline
Start engine, you will need to use gas pedal to start it
Then hold gas pedal steady and see if RPMs remain steady

So I think I found my issue one of the main vacuum ports wasn't capped and since I capped it, it's been running 95% better.
but does the ranger have a high idle til it warms up just seems like it just running high but i cant really tell with the exhaust not complete.

Yes, on cold start computer runs engine Rich with high idle, Choke Mode, all gasoline engines need to be "choked" when cold
Idle should be 1,100 or so but its based on coolant temp, higher idle for colder temp and it goes down as coolant warms up
When coolant gets above 150degF in the engine Choke Mode is off and you should have "warm idle", about 750 with manual trans, 800 with automatic

I still have to run the evap vacuum lines, finish the brake line and clutch hydro, build the exhaust. Other then that it sounds like it should. I have Trans fluid leaks I'm not sure why tho.

What are the troubleshooting steps for too much fuel as I have the same problem? Change the O2 sensors?

O2 sensors wear out after 12 years or 100k miles, so change them if they are old, that's where you START

Changing O2s doesn't "fix" anything, its like Bald Tires, getting new tires doesn't "fix" anything, just prevents problems

If your computer was basing air/fuel mix on "bad data" from worn out O2s then it may bring back up the MPG to what it should be

O2 sensors can be such a pain in the ass to get right as there are so many choices available and in my past experience it is best to just stick with OEMs parts. I was looking at the parts diagram and this is what I have found out for Ford OEM parts.

XL3Z-9F472-BA (Left Front)
XL3Z-9F472-AA (Oxygen Sensor, Front)
XL3Z-9F472-C (Ft Oxygen Sensor, Right)

GU2Z-9G444-A (Rear Oxygen Sensor, Left)
F85Z-9G444-DA (Oxygen Sensor, Rear)

I am assuming the rear ones are not needed in this case and that the front two share the same base part number? Being these are high costs items I was thinking with going with Bosch versions. Does anyone know if Bosch is the vender that makes these for Ford or not? If so what are the best Bosch part numbers to use?

I had o2 sensor codes I bought the walker ones off of rockauto and the code went away I haven't had a problem since. I bough the bosch ones until the walker ones came in then returned them but they worked good while I had them. Not sure if they are the same as the OEM ones but they are good and pricey

But how hard is it to bleed the brakes by now I have bled the brakes from the master cylinder and the lines 3 times now, the one thing I'm doing now is running fluid though the lines. But they are still soft has anyone had this problem with there break lines ?

The O2 sensors on all Rangers 1986 thru 2011 are the same, part number differences are related to the length of leads attached to the sensor and the connector type
Just FYI

Spongy Brakes is usually air in the system somewhere, as you have determined
1995 will have Rear Anti-lock brakes, RABS
RABS valve unit is in the drivers side frame rail just under front of cab area, it can get air trapped inside, hard to bled that out without an electronic device that opens the valves while bleeding

But try this test, no weight in the bed
Go to a gravel road and get up some speed then try to stop quickly, rear wheels should try to lock up and you will feel a pulsing in the brake pedal, thats the RABS working
Repeat testing, that should help clear any air out of the RABS unit
Then bleed rear wheels again

Rear E-brake(parking brake) adjustment
If the E-brake is not adjusted correctly then the rear wheel cylinders need extra fluid which means pedal goes down farther, easy fix
Hold out E-brake release handle and pump the E-brake pedal until it feel solid/tight, this adjusts the "star wheel" in each rear wheel to put the brake shoes at correct position, you can't "over tighten" it, it adjusts to where it should be and no farther