1997 Ranger 2.3L Hard to start in the morning.

[Pez]

Ok, so 97 2.3l with automatic. Bought with hard starting issue a few months back. Would never start easy. The previous owner(fellow employee) and owner before that both state the fuel pump, filter, regulator and plugs/wires replaced in effort to cure issue with no change. I checked over truck and all the issues I found lead to regulator which I replaced with also, no change.

Further digging and the fuel pressure checking ok I was at a loss. Began noticing air pressure released when fuel cap removed. Followed vent tube from tank to engine bay and found plugged with screw and various other vacuum lines treated the same. What I assume was happening was the fuel tank was pressurizing and that pressure was forcing fuel from the rail causing no fuel at the rail at start up? Fixed and rerouted vacuum and vent lines with a huge improvement. Did well and would now start quickly during the day but first start in the morning was still hard to start. Could deal with it for a short while, but now we are back at square one.

So the actually question is what in the fuel system do I need to inspect? Was wanting give pressure readings but my gauge is shot. Last reading I got was 35 psi at idle and around 40 to 45 psi at high idle.

Thanks for any input, hope we can finally cure this 4 year long issue.

 

[Mark_88]

Howdy Pez,

I would suggest checking two things first. The fuel pressure before you try to start the vehicle and the plugs to see if they are wet or smell like fuel. If you have the equipment you can also check inside the cylinders for fuel after the truck has sat overnight.

These will indicate if the fuel pressure is bleeding off from leaky injectors.

It only takes one to slowly drain the fuel pressure away and it may not be noticeable if the leak happens after you shut it down at night. There's only so much fuel in that rail and fuel evaporates fairly quickly.

You can check the oil for the smell of gas also because if it gets into the chamber it could potentially leak down past the rings...and that can lead to diluted oil which will lead to a fast burn out of the engine if left alone.

 

[tomw]

After an overnight rest, try cycling the key from OFF to ON, pause and listen for the fuel pump whine, move back to OFF, and repeat a few times. The short pump run can prime the fuel rail if a)an injector leaks, or b)the check valve(s) in the pump or return(vintage dependent) are leaking fuel from the rail back to the tank.
If it starts after doing the key cycle 4-5 times, I'd be looking at check valves in the pump, or regulator.
I'd also borrow a gauge and get proper pressure & delivery volume readings. If you have a vacuum diaphragm on the regulator, the pressure should jump when the vacuum line is pulled on an engine running at idle, and drop back when the vacuum line is re-connected.
tom

 

[RonD]

yes, as tomw said, you can restore lost pressure by cycling key on and off 3 times before trying to start engine.


But if it starts OK warm and not cold it could be something else.
When you start any fuel injected engine you should NEVER touch the gas pedal, you can of course but if you need to then there is a problem, so for this test do NOT touch the gas pedal.
Engine is cold
Try to start it, you can cycle the key on and off if you want first
When engine starts RPMs should jump up to 1,500+, then start to drop down to 1,100 or so, high but not too high
(this is without touching gas pedal)

This means IAC(idle air control) valve is working AND ECT(engine coolant temp) sensor is working

When you turn the key on the Computer(PCM) boots up.
First thing it does is to open IAC Valve all the way for starting
It then looks at the Engine temp, ECT sensor
If ECT sensor shows cold engine, then PCM enters Choke Mode
All engines need to be Choked so they can run cold, Fuel Injected engines can't use a choke plate like a carb so PCM has to emulate the Choke:
Rich Fuel mix, high idle and advanced spark timing

If ECT sensor is bad, showing engine is always warm, then computer just "thinks" you are restarting after short shut down so wouldn't set a code for bad ECT sensor

But engine would be hard to start cold and would run rough until it was actually warmed up, because Choke was never used

So test if you get high RPMs at Cold start, and if RPMs slowly drop to 750 or so after full warm up
If not then replace ECT sensor

Now there are TWO coolant temp readers on your 1997 engine, a SENDER for the dash temp gauge and the SENSOR for the Computer
SENSOR is the one you would change


And just as a heads up about the 2.3l(or 2.5l) Lima dual spark plug engines
Only the exhaust side spark plugs and coil pack are ON when starter motor is active
So when starting you are only getting spark on those 4 spark plugs

Intake side spark plugs and coil start working when RPMs are above 400, so after engine is started

Cold start issue could be spark related but would expect warm start to also be an issue if this were the case, but a cold engine does need hotter spark for the Rich Fuel mix
If exhaust side spark plugs haven't been looked at in awhile then I would have a look, could be they are just getting old


And just as a test to see if hard start is fuel or spark related do the 50/50 test
Cold engine
Try to start one time, just a few cranks to confirm a no start
Pull off air tube on upper intake
Open throttle
Spray some gasoline or Quick Starter(ether) into the intake
Now try to start engine again

If it fires right up then yes fuel delivery is the problem
If it still hesitates to start then look at spark system
50/50

 

[Pez]

Thank you everyone for the great response's! Did not have a pressure gauge till after work today but this morning I cycled the key 5-6 times and it started pretty quick.

Pressure readings from this afternoon on a warm engine are as follows:

Key on Engine off - 40 psi then ECM removes ground to relay after 1 second then it drops to 35 psi

Idle - 35 psi

High rpm - 42 psi

Idle with regulator vacuum line removed - 45 psi (Low? Shouldn't it be 65?)

Checked the front two exhaust side plugs and both where dry. I was ripping wires so did not check 3/4 until I get a new set of plug wires tomorrow so will update.

Also I will try and check pressure before key on in the morning if not I have thursday off and will check then.

Tomw, you mentioned check valves in the tank. Are these built into the fuel pump assembly or can these be replaced without replacing the pump assembly?

RonD, the ECT sensor is the two wire sensor correct? I had coolant temp codes when I first bought truck but they have not come back. May still replace sensor anyway.

As a little additional information I should of added was when this truck was first bought I was worried of leaking injectors. Also had a bad intake gasket so removed intake and cycled key multiple times and inspected injectors tips, never had a apparent leak but it was not left overnight. Just food for thought.


Again thank ya'll for the awesome replies!

 

[RonD]

1998 and up ran 60-70psi, Returnless fuel system, no Fuel Pressure Regulator(FPR) and no return fuel line

1997 and earlier 30-40psi, with FPR and return fuel line
The pressure in the system should hold when key is off, 1997 should drop no lower than 20psi with key off.......and stay there for MONTHS, not minutes, hours or days.....MONTHS

Your Pressure with engine running is fine, now test key off pressure, 0 psi at start up causes the no or slow start

If you are loosing pressure with key off, i.e. 0psi after a bit, then there is a leak
If you don't smell gasoline(fuel line, filter leak) then leak is either at the FPR or the check valve inside the fuel pump.
Maybe injector, but long shot there

 

[Pez]

Ok tested this morning before work and had 0 psi. Again key on, key off about 8 times and it started. I have personally replaced the FPR so we are left with the check valves in the pump and injectors. Will be pulling the plus in the morning, hope to find something there.

 

[Mark_88]

In all likelihood it is probably somewhere before the fuel rail but the injectors are a potential problem area. Just much less likely. It sounds like you are on going in the right direction either way and you have enough experience to fix it with the right information.

 

[RonD]

Leak injector cylinder will have black residue on spark plug tip from Rich startups

MPG would also be in the toilet

You can also just pull off the air intake hose and then cycle the key on and off 8 times, don't try to start it
Open throttle plate and smell for gasoline, you will smell it if an injector is leaking gas into the intake.

It's not like the old carb days, when you shut off the key the fuel injectors stop instantly, engine RPMs then wind down to 0 RPMs sucking out any "extra gas" or gas smell
And injectors don't start working until Computer sees a Crank position Pulse, so key on doesn't open an injector, only cranking engine will start them, so intake manifold should have 0 gasoline in it

 

[tomw]

The Ranger EFI went through several generations along the way. First had two pumps, a lift pump in the tank, and a pressure pump along the rail nearer the engine. There was also a filter canister rearward of the pressure pump.
Originals had a filter element in the canister. Later had the canister as a reservoir to provide fuel for high demand instances, no canister installed.
Inside the canister housing were 4 check valves. Two in the supply flow direction, two in the return flow direction. They were low-pressure check valves.
If the return check valves failed, you'd get leakback, and harder starting due to lack of fuel in the rail.
I cannot say where you have check valves, but likely in the canister, if equipped, or in the fuel pump. Perhaps another poster knows.
tom

 

[Pez]

Checked plugs and inspected for injector leak. Had no signs of leaking. Will also note I tried parking truck facing down hill to check the check valve theory and found truck start easier with only needing two key cycles. So, wild guess here is previous owner never replaced pump and I'm looking at pump assemblies and noting a average price of $60, then a huge jump to $200. Whats a brand ya'll recommend.

 

[tomw]

You can replace the pump only, re-using the 'sender assembly' that carries the gauge, float, and associated plumbing & connectors. The pump would be replacing the current pump. I do NOT know if the check valve is in the pump or the sending unit assembly.
Replacing the pump is a lot less costly than replacing the whole assembly. If you can find an OEM assembly at a price you are willing to pay, you should get OEM performance(should last as long as the one you have).
OTOH, you may find different brands in different packaging, depending on the vendor. I have seen OEM Motorcraft water pumps in non-OEM boxes, and sold at a reduced price from parts stores, so similar could happen.
If you are short cash, go for a price you think you can afford, that has a reasonable guarantee or warranty period. It's no fun to lift the bed and repeat the work, but an inspection of the parts before installation should give an idea of the quality.
tom

 

[RangerRich96]

You can do as suggested above, however I think the check valve is part of the 'greater' sending unit assembly. RA has quite a few options for complete fuel pump/sending units ranging from $50 on up. You can also purchase the complete pumps from AAP or AZ for under $100. I replaced the entire fuel pump/sending unit assy on my prev car, '00 Mustang w/ a Delphi unit and it worked fine, just slightly louder than the OEM pump but could only hear it running if you stood directly outside by the back of the car. I'd rather replace the whole unit. It would suck after you replaced the pump itself that your fuel gauge stops working or you have pressure leaking back into the tank.

 

[tomw]

Delphi a former division of GM that made components. They are good, or at least were.

Note that your gauge function will change if you replace the whole sender. The ramp of the resistance is not well regulated on assembly, so the gauge will indicate a bit different than original. My old sender would 'hange' near the 3/4 mark for a while, then, quickly descend to 1/2. Not in a mile, but pretty quickly. The replacement doesn't hang like that.
I don't know what other brands are good and reliable. I'd search a few sites for indications that Bob's Brand New Fuel Pumps may be the Brand to avoid...(not you, Bob)
tom