Please help, local mechanic wouldn't

[aidanramally]

My 2005 4.0 V6 ranger is having a few issues that even my local mechanic didn't wanna get into. First things first is the thing hard starts after sitting for more then a few minutes, it cranks fine and hard but it won't start until about 5 seconds of cranking. The only way to remedy this is by cycling the key 2 or 3 times to build fuel pressure. I've already replaced the fuel filter and breifly installed a new fuel pump but when it didn't fix the issue I returned it. the next issue is that it idles like shit, the rpms pulsate up and down and the whole engine shakes, it has never stalled. it has brand new plugs and wires. I thought maybe there was a vacuum leak but an unable to find one by spraying the lines with carb cleaner. I can hear a hissing sound coming from the drivers side but cannot find or confirm if it's a vacuum leak. I cut the cats so it has no 02 sensors but the exhaust shop I spoke to said that they often do that and it won't effect performance besides throwing a code. It has poor gas milage and sometimes the engine bay smells strongly of gas. Other than the 02 sensor codes there are no others. It runs pretty smooth when actually driving but will jerk and hesitate at certain speeds but will go away by giving it more or less gas. I've been chasing these issues for 4 months and haven't seen anyone else online with my combo of problems. it also has a new maf and and cleaned iac valve and throttle body. Does ANYONE have any ideas? This truck is driving me nuts and im on the verge of selling if this issue can't get resolved

 

[Ranger850]

the "new" fuel pump could have been bad out of the box. It happens from time to time. I would, A) try another new fule pump, or B) get a fuel pump that you KNOW works, ( working fuel pump from your buddy's Ranger). The cycling of the key to build pressure is why I say to go back to the pump for your issue.

 

[Bgunner]

Some pump/sending units have a check valve that goes bad and allows the fuel pressure to bleed off. Exactly where this is, in the pump or on the sending unit, I am unsure of but your issues point right to this.

maybe someone knows exactly where this piece is located and can point it out for you. If you just swapped pump and not the sending unit in total, you may have missed this.

 

[lil_Blue_Ford]

Ok... Lets try to break this down a little...

So I'll start with the elephant in the room. That exhaust shop that told you it would be fine to have no cats and O2 sensors? Either they are completely uneducated or they are just giving out terrible advice. Your truck was designed to be run with cats. They do not harm performance unless they are plugged. Straight piping (no cat and/or no muffler) does more harm to good to these more modern motors. The computer uses the upstream o2 sensors to adjust the air/fuel mix and the downstream (post cat) o2 sensors to make sure the upstream ones and the cat are doing their jobs. Eliminating these throws the computer into fits. At best it runs in emergency limp mode kind of deal. The absolute base programming. And it is terrible fuel efficiency. Basically closed loop operation that is the warm-up stage for the motor, before everything is up to operating temp. Also, it is FEDERALLY illegal to remove your cats and not replace them. TRS does not condone or encourage removing cats because it is illegal and especially because they need to be there for proper operation. You need cats and o2 sensors. Period.

I've had bad fuel pumps, regulators, and filters right out of the box. If you don't have a fuel pressure tester, you're just poking in the dark with the quality of parts these days.

I have never been able to find a vacuum leak using carb cleaner, brake cleaner, WD-40, propane, or any of the other typically suggested methods. Smoke machines can be had for under $100 these days and they actually do work for finding vacuum leaks. You can also use it to check for exhaust leaks, EVAP leaks and more. A hissing sound is indicative of a leak of some type. Fuel, exhaust, EVAP, vacuum, something... You need to track that down.

Most likely the computer is having fits because of these issues and that's what's causing the poor running. You should probably also replace the timing chain tensioners if you're over 80k miles on a set.

 

[Curious Hound]

Step 1. Put the cats and O2 sensors back and see how it runs.

Step 2. If still hard starting due to fuel pressure, there are 3 main places to check. Bad fuel pump/ check valve, leaking fuel pressure regulator, leaking injectors. With injectors being the least likely problem in my opinion.

 

[aidanramally]

Ok... Lets try to break this down a little...

So I'll start with the elephant in the room. That exhaust shop that told you it would be fine to have no cats and O2 sensors? Either they are completely uneducated or they are just giving out terrible advice. Your truck was designed to be run with cats. They do not harm performance unless they are plugged. Straight piping (no cat and/or no muffler) does more harm to good to these more modern motors. The computer uses the upstream o2 sensors to adjust the air/fuel mix and the downstream (post cat) o2 sensors to make sure the upstream ones and the cat are doing their jobs. Eliminating these throws the computer into fits. At best it runs in emergency limp mode kind of deal. The absolute base programming. And it is terrible fuel efficiency. Basically closed loop operation that is the warm-up stage for the motor, before everything is up to operating temp. Also, it is FEDERALLY illegal to remove your cats and not replace them. TRS does not condone or encourage removing cats because it is illegal and especially because they need to be there for proper operation. You need cats and o2 sensors. Period.

I've had bad fuel pumps, regulators, and filters right out of the box. If you don't have a fuel pressure tester, you're just poking in the dark with the quality of parts these days.

I have never been able to find a vacuum leak using carb cleaner, brake cleaner, WD-40, propane, or any of the other typically suggested methods. Smoke machines can be had for under $100 these days and they actually do work for finding vacuum leaks. You can also use it to check for exhaust leaks, EVAP leaks and more. A hissing sound is indicative of a leak of some type. Fuel, exhaust, EVAP, vacuum, something... You need to track that down.

Most likely the computer is having fits because of these issues and that's what's causing the poor running. You should probably also replace the timing chain tensioners if you're over 80k miles on a set.

Yes I was actually advised to cut them off because I was told my cats were clogged and was causing these issues... Right now it just has a muffler with no 02 sensors. so I guess based on replies the next course of action is
1. find a stock exhaust off a parts ranger and get new 02 sensors for it
2. try a new fuel pump
3. locate the vacuum leak

 

[Brain75]

lil_blue might have come off just a touch preachy on the whole cat thing, but I would agree. set aside and get your fuel pressure squared away, then figure out where you are in detail.

A) agreed get a fuel pressure gauge (or even a cheap $5 tire gauge at wally, using it for fuel = instead of lasting 30-40 years it will last 20 as the fuel eats the diaphram)
test your pressure at the rail in all conditions (after sitting overnight, before start, after 1 key cycle, after starting, while running idle, etc)

B) if your fuel pressure is off (I pretty much guarantee this from symptoms) then:
If you have a genuine Ford sending unit replace just the pump with another Bosch pump (it is cheaper than the whole unit and Ford used Bosch for OEM - they last just about forever). Aftermarket especially cheaper aftermarket is >50% bad out of the box.
... typically a new sending unit (whole) is like $95, just the pump will run about $65 (from someone else who did it recently, I have not myself). partsgeek or rockauto for vendors.
If you don't have a genuine Ford sending unit you could still replace just the pump and when your gauge stops working later fix that half then.


once we get your fuel system operating correctly see if you are running in limp mode, or codes but no CEL, or what.
C) Since you have a new vehicle, get a V-Linker Vgate ODB2 cable ($30-35), and download a copy of forscan (free)
that is $16 more than you will spend for a "cheap" OBD2 reader, but it gives you everything you can see and do for the vehicle - like live fuel trim (while running)
spend it now, because if you own the vehicle "forever" at some point you are gonna want/ need it (you can do all kinds of stuff besides diagnostic on newer models)

the strong smell of gas could be a leak, but with no O2 sensor it is more likely the computer going all over the place with fuel ratios and you are just smelling way rich.

spend the $40 now to get yourself setup diagnostically rather than spend $100 here and $100 there throwing parts at it trying to guess.

 

[Brain75]

also unless you are very sure you did it right, double check the filter didn't get installed backwards.

 

[Brain75]

FWIW, we are seeing more and more mechanics refuse to work on anything older than x years, just blanket without even looking.. the cost of labor has skyrocketted and they don't want to wrap up a lot of time in a vehicle that someone might stiff them on and then they have more into repair than they cold possibly get out.

You can also make a home-made smoke machine if that is an expense you aren't ready to jump on - I think there is a couple threads here, and other similar forums, if we get there and you are interested in the DIY might google it.

Don't know the bad rate for new MAF's but if you have old stuff in the corner of the garage (MAF and plug wires) hang onto them... "new is new, not necessarily good" is 100x more true now than when it was first uttered.

 

[aidanramally]

lil_blue might have come off just a touch preachy on the whole cat thing, but I would agree. set aside and get your fuel pressure squared away, then figure out where you are in detail.

A) agreed get a fuel pressure gauge (or even a cheap $5 tire gauge at wally, using it for fuel = instead of lasting 30-40 years it will last 20 as the fuel eats the diaphram)
test your pressure at the rail in all conditions (after sitting overnight, before start, after 1 key cycle, after starting, while running idle, etc)

B) if your fuel pressure is off (I pretty much guarantee this from symptoms) then:
If you have a genuine Ford sending unit replace just the pump with another Bosch pump (it is cheaper than the whole unit and Ford used Bosch for OEM - they last just about forever). Aftermarket especially cheaper aftermarket is >50% bad out of the box.
... typically a new sending unit (whole) is like $95, just the pump will run about $65 (from someone else who did it recently, I have not myself). partsgeek or rockauto for vendors.
If you don't have a genuine Ford sending unit you could still replace just the pump and when your gauge stops working later fix that half then.


once we get your fuel system operating correctly see if you are running in limp mode, or codes but no CEL, or what.
C) Since you have a new vehicle, get a V-Linker Vgate ODB2 cable ($30-35), and download a copy of forscan (free)
that is $16 more than you will spend for a "cheap" OBD2 reader, but it gives you everything you can see and do for the vehicle - like live fuel trim (while running)
spend it now, because if you own the vehicle "forever" at some point you are gonna want/ need it (you can do all kinds of stuff besides diagnostic on newer models)

the strong smell of gas could be a leak, but with no O2 sensor it is more likely the computer going all over the place with fuel ratios and you are just smelling way rich.

spend the $40 now to get yourself setup diagnostically rather than spend $100 here and $100 there throwing parts at it trying to guess.

Thank you I will definitely take your advice, I appreciate you going into such depth. I will get the pressure tested asap and go from there!

 

[Brain75]

obviously I haven't had to tear into the '07 yet, thanks for the heads up... did not know of the 3 ports on the newer style ones

 

[Snoranger]

lil_blue might have come off just a touch preachy on the whole cat thing, but I would agree. set aside and get your fuel pressure squared away, then figure out where you are in detail.

Lil_Blue sounds preachy about cats because The Ranger Station has a long standing policy that we don’t agree with removing cats. It’s a federal crime and not a topic of discussion allowed here.

 

[Brain75]

oh and I agree entirely, and I understand why. Just not my first troubleshooting "point a finger at it and nothing else" direction.

 

[Bgunner]

I don't know when they went to the 4x O2 sensor setup but the point remains the same.

Once the engine warms enough for eh ECU to enter closed loop the engine/ECU needs the O2 sensors to help adjust AFR. If an O2 sensor is not there the ECU will just run on a base tune and not run correctly.

Basic 4x O2 sensor set up. 1x in left bank downpipe, 1x in right bank downpipe: to tell ECU how much fuel/air is burn on combustion on that bank. 1x after the banks converge in the Y-pipe just before the cat and 1x just after the cat to determine the cat is working properly.

Without these O2 sensors you will have a Check Engine light and ruff running. You can weld in O2 bungs into the exhaust pipes and add a aftermarket cat so a factory style exhaust is not necessary but makes DIY easier.

 

[lil_Blue_Ford]

the fuel pressure regulator is inside the fuel filter.
that's why it has 3 ports, one of them is returning excess fuel to the tank.

have you tried using a rubber hose as a stethoscope to locate the hissing?

Nope, regulator is part of the fuel pump assembly, it’s on the end of that return leg from the filter.