93 Ranger stalling out after initial start up.

[Forces Delta]

Hello everyone,

I have 93 Ranger with a 4.0. I have been having an issue with the truck wanting to die or stalling out after start up. I have changed the fuel pump and fuel filter. I have tried running injector cleaner additives after fueling up with the same issue. The only thing that keeps it from wanting to stall out is when I give it a little gas. This is only happening when the start is first starting up for the day and when I'm leaving work. After that once I get the truck to idle I don't have this issue, it'll run smooth with no issues. Would love some help trying to keep this gem running. Thanks in advance for the help.

 

[JOLENE_THE_RANGER]

this happens to me also with the first start of the day. itll run real rough and sound like its not gettin any fuel when i try to rev it up. if i shut it down and restart 2 seconds later its totally fine

 

[RonD]

Could be the ECT sensor
All gasoline engines need to be choked when COLD, choke means Rich Mix and high idle for Fuel Injected engines
So computer has its own Temp sensor for coolant, no connection to dash Temp sender/gauge(12volt 1 wire, in 1993)

ECT sensor is 5volts and 2 wires
With key on Computer looks at ECT temp, if under 150degF then its set Choke Mode, but it varies by temp, richer mix and higher idle at 40degF engine temp than 80degF engine temp
So the amount of Choke needed varies by temp
ECT sensor is the source of that temp

So if ECT sensor is showing 120degF when cold, then engine wouldn't stay running if it was actually 60degF
Holding throttle open a bit mimics "choke mode", i.e. richer mix higher idle
Once cylinders have warmed up a bit you could release throttle


Could also be fuel pressure draining off after vehicle sits long enough, but simple test for that
Cycle key on and off 3 times before starting, that would restore 30psi fuel pressure, from 0psi
1 cycle from off to on = 10psi added to fuel system

So if pressure was 0psi and you turned key on once you would have 10psi
Start engine and it drops close to 0psi as injectors open, before fuel pump comes on full time, so engine struggles or dies
Restarts better because your not starting at 0psi because fuel pump was running for a bit

EDIT: last one reads like Jolene's issue

 

[rusty ol ranger]

I think OP needs to check/clean/replace the IAC. Sounds like maybe its sticking closed after an extended shutdown

 

[Eddo Rogue]

Its an old truck. Just give is a little gas to start. Or do what RonD said.
Might be your fuel pump on its way out if it gets worse.
Mine sometimes fires right up, other times needs a little encouragement. Its liveable.

 

[Forces Delta]

ECT sensor is 5volts and 2 wires
With key on Computer looks at ECT temp, if under 150degF then its set Choke Mode, but it varies by temp, richer mix and higher idle at 40degF engine temp than 80degF engine temp
So the amount of Choke needed varies by temp
ECT sensor is the source of that temp

So if ECT sensor is showing 120degF when cold, then engine wouldn't stay running if it was actually 60degF
Holding throttle open a bit mimics "choke mode", i.e. richer mix higher idle
Once cylinders have warmed up a bit you could release throttle


Could also be fuel pressure draining off after vehicle sits long enough, but simple test for that
Cycle key on and off 3 times before starting, that would restore 30psi fuel pressure, from 0psi
1 cycle from off to on = 10psi added to fuel system

So if pressure was 0psi and you turned key on once you would have 10psi
Start engine and it drops close to 0psi as injectors open, before fuel pump comes on full time, so engine struggles or dies
Restarts better because your not starting at 0psi because fuel pump was running for a bit

EDIT: last one reads like Jolene's issue
[/QUOTE]

Thank you very much I will look into the fuel pressure first sense that's straight forward and won't cost anything, but it does sound like the ECT. Once I give it a little be of gas it'll hesitate for a second but then start idling just fine. Unless I'm reading this wrong. Also is the ECT why on most vehicles the initial start up the it will have a higher idle at first?? I know how to replace parts on a vehicle but that's about it. Still trying to learn more about them.

 

[Forces Delta]

Its an old truck. Just give is a little gas to start. Or do what RonD said.
Might be your fuel pump on its way out if it gets worse.
Mine sometimes fires right up, other times needs a little encouragement. Its liveable.

Oh I get it's an old truck and you're correct it is livable. I'm just trying to learn more things about vehicles and was just making sure that I wasn't missing something huge or if this was going to be a problem.

 

[Forces Delta]

I think OP needs to check/clean/replace the IAC. Sounds like maybe its sticking closed after an extended shutdown

I will look more into this thank you. From what I'm reading it might be but also the ECT both parts don't seem to be very expensive but I'll try the ladder first. Worst case I replace a few parts, have new parts, it works, and I'm learning more.

 

[rusty ol ranger]

I will look more into this thank you. From what I'm reading it might be but also the ECT both parts don't seem to be very expensive but I'll try the ladder first. Worst case I replace a few parts, have new parts, it works, and I'm learning more.

Just remember though new parts dont always mean good parts lol

 

[RonD]

Yes, ECT sensor tells computer the engine temp on start up
Computer will then set richer mix and higher idle based on engine temp, which is based on that temp from ECT sensor

So if you haven't been getting idle at 1,000rpms on cold start then could be faulty IAC valve as mentioned, but could be ECT sensor is telling computer engine is already warmed up, when it isn't

 

[rusty ol ranger]

Yes, ECT sensor tells computer the engine temp on start up
Computer will then set richer mix and higher idle based on engine temp, which is based on that temp from ECT sensor

So if you haven't been getting idle at 1,000rpms on cold start then could be faulty IAC valve as mentioned, but could be ECT sensor is telling computer engine is already warmed up, when it isn't

Dont ECT's normally fail rich though? As in motors warm but sensor thinks its cold?

I guess it could go both ways though

 

[Forces Delta]

Just remember though new parts dont always mean good parts lol

Makes sense

 

[RonD]

ECT sensor is 5volt in and 2 to 3 volt out if engine is cold, colder it is the higher the out volts
Under 1 volt out is warmed up

So any corrosion on wiring can lower voltage, i.e. 5v in becomes 4v in, or 2volt out becomes 1v out
Or the sensor itself can fail

There are ECT sensor codes, but only if the voltage out to computer is absent or voltage doesn't change at all within 4 to 5 minutes of start up
Computer doesn't have a record of when it was last on, so lower voltage on cold start just means less Choke, because engine is already warmed up
And voltage would change a bit as it warmed up so no codes

 

[89Twincharge]

Fuel pressure bleeding off, guessing sending unit if no leaks visible!!

 

[4x4junkie]

You might also check the vacuum manifold (tree) for missing / broken / disconnected caps and/or hoses.
I had this issue come up on my '94 (the engine would rev up to 3K or so RPM immediately upon startup, then 2-3 seconds later it would die if I didn't give it a bit of gas). The culprit was a disconnected vacuum hose to the cruise control solenoid. Reconnected it, and all was fine again.