Wasting money on a 3.0 that starts and immediately dies

[eighty6gt]

So many threads on this, I've searched and searched.

Truck will fire and run on brake cleaner as long as I'd like it to.

I didn't have my fuel pressure gauge in town (it's here now but I don't have the damn fitting to go from schrader to whatever it's got on it....) I have another 3.0 ranger, I pressed the schrader -seemed to be a lot less pressure in the broken truck. Suspected fuel pump. Changed pump and filter. Same behavior. Jumper fuel pump, can hear fuel rushing through rail with truck off. Maybe the regulator is bad and it's allowing fuel to free flow? I will try to borrow it from my good truck and see. Not sure if it's integral to the rail.. I don't think so.

Read that the synchronizer can cause the ecu to not trigger the injectors if it doesn't send the signal after startup. Replaced that, same behavior.

Suspected the crank sensor could also be needed for the ecu to fire the injectors. Replaced that, same behavior.

I'm down to:

- ECU power, which probably isn't it as the truck runs on brake cleaner. Broken ECU?
- ECU looking for oil pressure in some parallel circuit besides the dashboard (which shows all good,) and shutting engine off? (this is folklore I've read.)
I'm at a loss, I think I will have to part the truck out.

Thanks!

 

[RonD]

Welcome to TRS


What year is this Ranger 3.0l?
1996?
You mention a second Ranger so just want to make sure

Crank sensor times the spark and fuel injectors and it is working or you won't have spark, which you do since it starts by adding fuel manually.

Cam sensor is for fine tuning best injection timing, but in some model years a Cam sensor issue could cause a no start, so year is important

1999 and up V6 Rangers had PATS(passive anti-theft) it disabled fuel injectors if correct PATS key was not used in the ignition, if that happens the Anti-theft light on dash flashes rapidly.
Engine could still be started by add fuel manually but no fuel from injectors for continued running

And if you have ANY pressure at the schrader valve engine should start on its own, IF injectors are working
1997 and earlier Rangers used 35psi fuel pressure system, 1998 and up use 65psi pressure system, so again year matters

It reads like your injectors are not opening, which would be a computer(ecu, PCM) issue
Since day one of fuel injection the computers sole purpose was to time and open the injectors, over the years computer has been tasked with other uses but at its core is running the fuel injectors, base function.

When you turn on the key the CEL(check engine light) should come on, thats the computer powering up

You can reset the computer by unhooking both battery cables and touching them together, this clears "saved" memory and makes computer "relearn" some of the system, also clears Radio presets, lol.

Computer doesn't "know" you want to start the engine, it has no connection to the key or starter motor.
When you turn on the key you should Hear the fuel pump in the tank run for 2 seconds, but only for 2 seconds, you can turn the key off and on as much as you want to confirm you hear the pump and to build up pressure in the system, you can't over pressurize the system

When computer "sees" a signal/pulse from the crank sensor its starts the spark and then a second later the fuel injectors.

The fuel injectors ALL get 12volts when key is ON
Test that at least one does have 12volts with key ON, if not then you have a blown fuse or bad wire.
The 12volts is on the Red wire and it just daisy chains from one injector to the next.
The 12volts comes from engine fuse box
The Computer Grounds each injector to open it, so there will be 6 Ground wires, one from each injector running back to the computer.
If one wire was bad engine would start but have a mis-fire
So either no 12volts, or Computer is not pulsing Ground to ANY injector

 

[cbxer55]

In late 2009, and this January, I had the exact same problem. Would start and run on starting fluid or brake cleaner, but would not run on it's own. When I had the truck delivered to my local FORD dealer, they found the injectors were badly clogged up. They ran a special mix through them and got them clean. This lasted a week, and it started doing it again. Since then I have been using the E10 fuel mix, or adding an amount to be considered 10% of E85 to my fuel tank on fill ups, haven't had another problem since doing this. In fact, it's running better than it ever has in the last 7 or 8 years, and the CE light is staying off as well, which is unusual for my truck. It's usually always lit up with the P0171/174 codes for lean. Since running ethanol in my fuel, that is no longer the case.

Note that I tried that crap known as SeaFoam and it didn't do squat. Berryman's B-12 works like a champ for badly plugged injectors, but you may need to use two cans in a full tank at first. I've done it many times in the last 8 years, doesn't hurt a thing.

 

[eighty6gt]

I'm taking the injectors/intake etc all off as a result of the following:

removed and replaced fuel pressure regulator with known good - same result
node light on one injector - injector firing when cranking and when running on brake cleaner
backprobed and checked all ignition wires - good

ran fuel out of the feed side of the regulator mount - rubber adapter, clear line, found debris.

 

[JP02XLT]

I would change the fuel filter & get a guage to check / confirm the fuel pressure. You can unplug the injectors while its running (if you can get it running) to help cycle the injector completely, sometimes this will dislodge any buildup on the tip.

JP02XLT

 

[eighty6gt]

I'm betting there are cups of soil in the top of the injectors - on my newer ones there's a screen there that wouldn't pass this type of debris. I can also do some cleaning, I think removing the upper intake is a 5 minute job.

The filter is new - if the pump passed enough stuff to plug it again I'd be kind of concerned.

 

[eighty6gt]

with ignition on I see battery voltage at the injector hot side.

I will clean these up, screens and rail aren't plugged. Suspecting lack of voltage delivery to fuel pump, going to connect directly to a battery when I put all of this back together. My fuel pressure regulator o rings were shot so I need to drop by a hydraulic shop or something and grab some.

 

[RonD]

Well if you hook battery back up and turn on the key fuel pump should run for 2 seconds, so fuel should flow out of the now disconnected fuel line

There are a few DIY fuel injector cleaning video

And if injectors were getting ground pulses then only thing left is fuel pressure or clogged injectors

 

[eighty6gt]

Cleaned the injectors and the rail and the engine, put it all together, fired with the inlet piping off. Installed inlet tubing, MAF, and the truck wouldn't start again. Took inlet tubing off, fired up. Plugged in MAF with truck running, stalled.

www.youtube.com/watch?v=fvyRJ_sjnF4

www.youtube.com/watch?v=HaMyYt57bRU

Swapped MAF and housing off of my other 3.0 ranger, truck runs great and does burnouts.

Now to find an MAF. I think the junkyard.

 

[RonD]

Good work

Check MAF wiring connector.

MAF is an important sensor but on Cold Start computer is using pre-set air/fuel mix for engine size and RPM