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Need Help With Hard Start Only With Cold Starts


SideStepRanger

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Vehicle Year
1999
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Ford Ranger
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Automatic
99 Ranger with the 3.0 takes 3 - 4 key turns to start the truck after it's been sitting over night. On about the 4th try it will sputter and then I give it gas and it starts. It also stalls if I put it in gear too soon after it gets started. After it starts it drives good, and restarts with no problem once it's warmed up. I'm thinking it's either clogged injectors or a bad fuel pump.

Now here's the fun backstory.
Gas is getting very expensive, but E85 is over a dollar cheaper per gallon. Having a flexfuel I decided to give some E85 a try since I can save about $20 per fuel up and here's what happened:
- CEL came on after first fuel up, but everything else still seemed fine.
- Replaced the fuel filter to fix the CEL
- After fuel filter replacement the CEL went off and stayed off, but the truck had no power at all and could barely make it up hills. The hard to start issue also started.
- I replaced the fuel filter again with a different brand, and the power returned back to normal but still hard to start with a cold engine.
- I replaced the IAC valve but that didn't change anything.

Could it be clogged injectors or a bad fuel pump?
 
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Rock Auto 5% Discount Code: 7FA902352B4C01: April 5th, 2021

RonD

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Doesn't sound like either
Bad fuel pump would show up as loss of power at highway speeds, same for injector issues

Reads more like Choke issue or loss of fuel pressure when key is off
Cold gasoline engine needs to be Choked, needs a Rich fuel mix for first few minutes
With fuel injection this is done using the ECT(engine coolant temp) sensor, it tells computer the coolant temp so when to apply "choke mode"
There are two temp units on the engine
ECT sensor, 2 wire, 5volts, only used by the computer
ECT SENDER, can be 1 or 2 wires, 12volts, only used by dash temp gauge
looks like 1999 Sender uses a red/white wire and a black/white wire<<<<< so NOT the correct one to change

On cold start if you have a high idle, 1,100+ RPMs and then it slowly drops to about 750 after 5-8 minutes then ECT sensor is most likely working fine
If you don't have the 1,100+ RPMs on Cold Start then change ECT sensor
Choke mode = high idle and rich fuel mix


But first test if fuel pressure is the issue
For safety reasons the fuel pump only runs for 2 seconds when you turn the key on
The 1999 Ranger fuel system runs at 55psi pressure
With key off it should stay above 30psi, for MONTHS and MONTHS

With key on and that 2 second run time it adds 10psi of pressure to the 30psi, so enough to start engine easily
If pressure has dropped to 0psi....................then 10psi its not enough

So cycle key on, count to 3 and then key off
Repeat 3 times, so get 30psi pressure back, assuming 0psi
Then try to start engine

If it starts up and seems to run OK, high idle and no stalling, then loss of pressure is the issue
Unfortunately, loss of pressure with key off in 1999 can only be an issue in the fuel pump assembly in the gas tank, so new fuel pump assembly, it has new fuel pressure regulator and fuel pump with check valve
 
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SideStepRanger

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Thanks Ron. I'll buy a tester for the fuel pressure and report back.

One other concern is that my battery is reading 12.45V with engine off in 75F weather. That is slightly low on voltage, but is it low enough to cause starting issues? It is getting corrosion on the positive terminal.
 

SideStepRanger

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San Diego, CA
Vehicle Year
1999
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Ford Ranger
Transmission
Automatic
Doesn't sound like either
Bad fuel pump would show up as loss of power at highway speeds, same for injector issues

Reads more like Choke issue or loss of fuel pressure when key is off
Cold gasoline engine needs to be Choked, needs a Rich fuel mix for first few minutes
With fuel injection this is done using the ECT(engine coolant temp) sensor, it tells computer the coolant temp so when to apply "choke mode"
There are two temp units on the engine
ECT sensor, 2 wire, 5volts, only used by the computer
ECT SENDER, can be 1 or 2 wires, 12volts, only used by dash temp gauge
looks like 1999 Sender uses a red/white wire and a black/white wire<<<<< so NOT the correct one to change

On cold start if you have a high idle, 1,100+ RPMs and then it slowly drops to about 750 after 5-8 minutes then ECT sensor is most likely working fine
If you don't have the 1,100+ RPMs on Cold Start then change ECT sensor
Choke mode = high idle and rich fuel mix


But first test if fuel pressure is the issue
For safety reasons the fuel pump only runs for 2 seconds when you turn the key on
The 1999 Ranger fuel system runs at 55psi pressure
With key off it should stay above 30psi, for MONTHS and MONTHS

With key on and that 2 second run time it adds 10psi of pressure to the 30psi, so enough to start engine easily
If pressure has dropped to 0psi....................then 10psi its not enough

So cycle key on, count to 3 and then key off
Repeat 3 times, so get 30psi pressure back, assuming 0psi
Then try to start engine

If it starts up and seems to run OK, high idle and no stalling, then loss of pressure is the issue
Unfortunately, loss of pressure with key off in 1999 can only be an issue in the fuel pump assembly in the gas tank, so new fuel pump assembly, it has new fuel pressure regulator and fuel pump with check valve
I hooked up a fuel gauage and it showed 0 psi. When I turned the key to the on position without starting it immediately went to 55psi. Does this mean the fuel pump is good?
 

RonD

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yes, but unless the pump was hot wired it should only go to 10psi, and with repeated off and on of the key it would get to 55psi

The fuel pump should only run for 2 seconds at each key off and on, and that adds about 10psi each time
 


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