I have read many threads about this topic and I have tried to fix the problem but I really need someone’s expert advice.

my father bought this truck new and gave it to me before he died in 2019. It has 235,000 miles on it. I’m sure he had it serviced regularly and it really ran well when I got it. Last year the alternator went bad on it and I took it to a shop to replace it. Shortly thereafter, I noticed that although it cranked easily and would idle, it would stall when I tried to accelerate. I would have to either have to pop the clutch or push the throttle while in neutral to keep it running. After about 5 miles, I could come to a stop without it stalling after it warmed up.

The CEL never came on until I realized that the bulb was burned out. I replaced that and scanned the computer. I showed that the Purge Valve was faulty so I changed that. No improvement. So I started throwing parts at it. I changed the fuel filter, air filter, purge solenoid, ECT , IAC and FPR. I cleaned the MAF. I checked and replaced some vacuum hoses. I noticed that fuel was leaking if I added to much fuel to the tank. I removed the bed and saw that the filler tube was cracked at the bottom. I replaced that. The filler tube was maybe for an extended cab as it was too long so it has a bend in it at it top but fuel flows easily through it. I changed the plugs and wires. Added a can of Seafoam to gas. No change.

I rented a fuel pressure gauge. KOEO, 3 PSI. Turned key off and on about 5 times and pressure went to 20, then slowly fell. Cranked engine and pressure on went up to 26 PSI and held there. I pulled the vacuum hose from the FPR and it went up to 40 PSI.

So, I have spent a lot of time and effort on this and would welcome your input. Obviously, I have a fuel issue. What should I tackle first? Change potentially leaking injectors? Kinked/ clogged fuel lines? Fuel pump issue? Vent problem on tank?

 

Welcome to the forum

I don't think fuel pressure is the issue for the stalling, but yes it should be 30-35psi with engine running FPR vacuum connected
Anything above 20psi running will be fine, might set a lean code but that's all
0psi at cold start could see engine stall on first start, but should start and run fine after that

Fuel pump is capable of 80+psi
FPR is rated at 43-45psi
So no vacuum at FPR should see 43-45psi engine running, lower could be the test gauge............or weak fuel pump
Test gauge could be off 5psi so 26 is 31 and 40 is 45, so your fuel pressure is "normal"

I wouldn't think leaking injector, or your MPG would be way way down in the toilet and tailpipe would show grey/black smoke with misfires


Cold gasoline engines need to be Choked or they will stall until warmed up
The Colder outside temp the more choke is needed and the longer it takes to warm up and no choke needed

On fuel injection the Computer(PCM) does the Choke, Choke means to run Rich Fuel Mix with high idle, that's what a choke plate did on a carburetor
The PCM gets the coolant temp from the ECT sensor with key on
If coolant is below 140degF it "sets the choke" for the temp it shows, say 50degF
When you start the engine PCM will be adding extra fuel and will use the IAC Valve to set idle above 1,000rpm, up to 1,200rpm, the colder it is the higher the cold start idle
As coolant warms up PCM lowers the idle, don't have to tap the gas pedal, lol, like on Carbs

Does this happen on cold start?

ECT sensor is 2 wire 5volt unit located top front of the 2.3l engines
Temp sender for dash board temp gauge is 12v and located at drivers side rear by oil pressure switch

IAC Valve needs to be Motorcraft or Hitachi brand and rarely fail but are often replaced, other brands are not true solenoid valves so will not work well
IAC Valves can be cleaned

You have dual spark plugs for extra power, but one of the downsides is that you will not feel an issue if one spark plugs in a cylinder is not working, they both fire at the same time
So what you should do once a year is to test each set of 4 spark plugs on one coil pack, and its simple to do
Each coil pack has a 3 wire plug in
On warmed up engine unplug one of the 3 wire connectors, pull it back far enough so it can arc back to its coil
Start engine
Should run smooth no misfires, these 2.3l engines used only 4 spark plugs from 1974 thru 1988 so it will run and drive fine like this
Repeat test but with other coil pack unplugged
This will tell you if all 8 spark plugs are working

 

Thank you RonD,

“When you start the engine PCM will be adding extra fuel and will use the IAC Valve to set idle above 1,000rpm, up to 1,200rpm, the colder it is the higher the cold start idle
As coolant warms up PCM lowers the idle, don't have to tap the gas pedal, lol, like on Carbs

Does this happen on cold start?”

Yes, this happens on cold start. But if I don’t wait for about 10 minutes, it will stall with I tap the accelerator.

I will check the coil as you recommended. Is it common when engine warms, engine will not stall although the coil may be bad?

 

No, usually not a bad coil pack, you are check if all 8 spark plugs are working

Throttle should have no effect on Choke mode, so that is odd
IAC Valve' air passage by-passes the throttle plate to allow more air into the intake to set higher idle
If you open throttle plate more, tap gas pedal, computer should just respond by adding more fuel but leave IAC Valve alone at its current voltage/setting based only on coolant temp


Bluetooth OBD2 reader is a good investment at under $15 as it works on any vehicle 1996 and newer, not a Ford or Ranger thing, ANY vehicle, its The Law
You can then watch LIVE data that the computer is seeing from each sensor on your smartphone or tablet, APP is free, or $5 for deluxe APP, lol
You could then see what computer is doing in response to tapping on throttle
Also cold start temp, MAF data, ect...............

 

Thank you again. I forgot to mention to you that when the push accelerator to floor and crank, it fires up. That’s why I mentioned the injectors. I am having the same problem as this guy from this post:
https://www.ranger-forums.com/genera...n-cold-140913/

 

Thank you again. I forgot to mention to you that when I push the accelerator to floor and crank, it fires up. That’s why I mentioned the injectors. I am having the same problem as this guy from this post:
https://www.ranger-forums.com/genera...n-cold-140913/

 

You might have a stretched throttle cable
Google: Ranger throttle cable mod
Easy simple fix

So you are not getting WOT(wide open throttle) voltage from TPS(throttle sensor) to computer with pedal to the floor

You can test TPS voltage or see its % on OBD2 reader
TPS is a 5volt sensor
Center wire on TPS, pierce it with a sewing needle
Ground DC Volt Meter to battery neg or engine metal
Key on, engine off
Center wire, throttle closed, should show 0.69 to 0.99volt, under 1 volt, thats 16-19% of 5volts
At WOT you should see 4.5-4.6volts, thats 90-92% of 5v

The 4.5v or 90% will initiate Clear Flooded Engine at 0 RPMs which shuts off injectors

 

I checked that with my OBD2 reader. Throttle closed 16.9%. WOT 91%.

 

Then "clear flooded engine" should cause a no start, so odd