3.0 Rough Starting

[Lamoureux]

Hey guys,

Every time I go to start my ranger I crank the key a couple times and nothing happens. It cranks fine and acts like it wants to start then after the 3rd or 4th time cranking the truck the motor finally starts but has a real bumpy idle to it at first. After about 5 seconds of rough idle the truck goes into high idle like it should and runs completely fine. Once the truck is warm and I've driven it around for awhile if you turn the truck off and turn it back on the engine fires right up no problem. It has a new fuel filter and spark plugs (except for 2 of them I couldn't get out). I'm curious if anyone else has had this problem, thanks!

 

[RonD]

You may be losing fuel pressure when the truck sits for a few hours.
'96 should have 35-40psi of fuel pressure at the engine.

Fuel pressure on '96 is held by Fuel Pressure Regulator(FPR, on engine) and Fuel Pump's Check valve(in gas tank).
Also the fuel injectors but since you didn't mention a drop in MPG, or Check Engine Light(CEL) being on we can assume those are not leaking fuel into the engine.
And I assume you don't smell gas or would have mentioned it, so no leaking fuel line.

Quick test to see if this is the problem:
Next time truck sits over night
Turn key on(you will hear fuel pump run for 2 seconds)
Turn key off
Turn key on again, count to 3
Turn key off
Turn key on again, count to 3 and now try to start engine.

Each time key is turned on the computer runs the fuel pump for 2 seconds and only 2 seconds, it won't run again until engine starts.
This 2 seconds creates about 10psi of pressure, so 3 on and offs would create about 30psi, normal pressure.

If it starts right up then you do have a pressure leak
If it doesn't then it is another problem.

Most auto parts stores rent or loan fuel pressure gauges, there is a test port on the engines fuel rail, just to confirm pressure is dropping with engine off.

FPR is the easiest to change, as check valve on fuel pump requires removing and replacing fuel pump.

 

[Lamoureux]

Awesome, great advice.

I will defiantly try that trick to see if I can narrow down what could be causing the problem. I did forget to mention my engine light is on, so If the "turn key" trick doesn't work maybe it could be the injectors.

 

[RonD]

Yes, could be.

You need to go by an auto parts place and they will read the computer codes for free.
WRITE THEM DOWN!
Then ask them to reset computer.
Do NOT buy anything to "fix" a code number, that is not what those are for.

Code numbers make alot of sense IF you think like a computer, we don't, lol, so what we think they mean is usually wrong.

 

[Lamoureux]

So I went to get the codes checked at autozone and come to find out, there is no power to my OBD2 port. I checked all the fuses and they all look good to me so I guess I need to trace the power wire and see whats causing the problem.

 

[RonD]

Look at fuse #5 10 amp DLC(data link connector)