At my wits end with fuel/ignition problem

[Horj]

Hope you guys can help me I've got an '02 Ranger Edge, 3.0 V6. A couple of weeks ago, my truck started running horrendously. No power on acceleration and the engine shook like crazy. The CEL codes read that I had a misfire on 4 and 6. I changed the coil pack, plugs (properly gapped), wires, air filter and put a bottle of fuel system cleaner in the tank and it got a little better. I've got good spark on all wires. When I take the wires off of 4 and 6, the engine still runs crappy, but when I take them off the other ones, it runs crappier still. I checked the injectors and swapped a couple around but it made no difference. Still running kinda rough. I did another code read and it gave the code for MAF sensor and O2 sensors. I cleaned the MAF sensor and it got better still, but it's still not 100%. I've also had Meineke do a professional fuel system clean, but not sure the guy that did it did everything he was supposed to. When I removed the injectors (after the "pro clean"), a couple looked as though they had been dragged through mud. Cleaned them with carb cleaner before I swapped them around and put them back in. So, my problem now is that it's still running kinda rough, it backfires slightly and pings somewhat, not much acceleration and it's burning through fuel like crazy. Please help! Thanks

 

[Horj]

I forgot to mention that I also replaced the fuel filter.

 

[monsterchuck]

What are the specific codes? There are dozens of different MAF and O2 sensor codes. Specifics here may help.

 

[Horj]

Will have to get back to you on that. It's been over a week since I had them read. I'll hit up the parts store tomorrow and confirm those codes.

 

[aspevacek]

where do you get your fuel at? was i tfilled up prior to this running issue starting? Have you looked at the fuel pressure to see what that is reading? was the filter clogged up at all that you replaced, as in did fuel flow thru it as fast from either side when you turn it up on end?

Get the actual fuel pressure checked to see what that looks like, as fuel pressure plays an important role in the running of a fuel injected motor.

 

[RonD]

Yes could be water in the tank from a bad fill up.

Does it run better cold?
If so, could be electronic choke acting up after engine warms up, the ECT.
http://oldfuelinjection.com/?p=28

The bad gas mileage may be a clue, ECT will cause that, also the fuel rail has a regulator that has a vacuum line attached, if the regulators diaphragm starts leaking, raw fuel will be sucked into the intake, causing your symptoms.
Remove that vacuum line and check it for fuel or the smell of fuel.


The pinging is the odd man out, that could be timing chain tensoiner issue when other problems are included, or CPS(cam position sensor), this is located in the old distributor hole at the top rear of the engine, it tells the PCM(computer) when to fire coils.
http://www.therangerstation.com/tech_library/camshaft_position_sensor.html

These are a weak point known to fail, usually there is a squealing sound but not always
Codes that can come up from CPS issues are P1336, P1309 and P0340

 

[Horj]

Thanks for all the responses! I have a couple of quick questions before I head out to the parts store.

RonD - How would I determine between the sensor or the synchronizer that's gone bad? I've had a squeak coming from there for awhile now, and a mechanic friend of mine just added a little oil to the synchronizer where it passes the magnet in the sensor and that took care of it for awhile. Should i go ahead and replace the whole shebang, sensor and synchro?

Regarding the ECT, that reminds me of another problem I've been having. Occasionally, when I first start the truck for the first time in a day, after about 4-5 minutes of driving the temp gauge will go way high, not red-lining, but almost. It goes back down on it's own after awhile, but if I turn my heater on briefly, the temp gauge goes back to normal a little quicker and will stay there for the rest of the day. This happens almost everytime I drive it. Could this be the gremlin that's causing that or maybe the thermostat?

aspevacek - I get my gas from various gas stations, mostly either Racetrac, Murphy (Walmart) or Circle K. Wouldn't the fuel system cleaner take care of a water in the tank problem or would I have to buy water remover specifically, if that's indeed the problem?

How do I go about checking the fuel pressure?

The old filter was pretty clogged. After letting it sit and drain for a bit, I blew air through it and it was difficult to push through. The new filter blew through easily.

I'm on my way to the parts store now and will write down which codes are currently showing. Thanks again for all you guys' help!

 

[RonD]

Did you read through the link about the CPS?
Yes, replace it, downside is no oil pressure, so a blown engine.
Squeaking means bushings are worn and shaft will start to wobble, so even if that's not "the problem" it is "a problem", lol.


My '94 had the up and down temp gauge, flushed system, twice, no change, I replaced the t-stat, no change, replaced the fan clutch, no change, did head gasket test, it was fine.............................................arrrgh

It was the darn heater core, I did notice heat wasn't super hot but still worked fine for me.
Seems like Ford uses the heater core as the by-pass until t-stat opens, so engine would heat up, spike, then go back down when t-stat opened, then temp would randomly go up and back to normal never HOT but up from normal now and then.

$28 heater core and 20 minutes fixed the problem, very easy to replace these.

My '94 just had 2 heater hoses from engine to core, no valves.
Some Fords use a by-pass valve, it is in the engine compartment near the firewall, 4 hose connections, this could also get plugged up so flow is blocked with heater off or heater on.
To test if this is the problem just by-pass the heating system, connect the 2 engine hoses together or remove 1 hose and use the other for the loop in and out.

 

[Horj]

The only code that showed up this time is P0171 System Too Lean

 

[RonD]

That would explain the pinging.

vacuum leak possibly, PCV valve and hose, vacuum manifold hoses

On the fuel rail there is a schrader valve, it looks like an air valve for a tire, you use a pressure tester on that to see what the fuel pressure is with engine off key off, engine off key on, engine on at idle, engine on at high RPM.
Write it all down.
The PCM(computer) assumes a certain pressure and opens the injectors for a specific length of time based on that pressure, if pressure is to low then not enough fuel is sprayed into the intake, so lean condition
Fuel regulator on the rail controls that pressure(vacuum line) as does the fuel pump.

I would still change the CPS....for sure

 

[Horj]

I'm getting the pressure tester tomorrow. Will let you know what the results are.

On a side note, I really miss my old '71 Ford Torino Wagon right about now. lol

 

[RonD]

Yes, we should have refused to buy cars with radios in them, that's what started this "let's run the whole car on electronics", BS
Slippery slope and down we went.

Can't wait for my first electric car.
"Car won't start??"
"It's the battery!!"
LMAO

 

[Horj]

Here are the results of the pressure test:

key off/engine off: 15psi
key on/engine off: 28 psi
key on/engine @ idle: 68 psi
key on/engine revved: 65-68 psi

When I revved the engine, it dipped down slightly to 65 psi, but came back to 68 psi

 

[aspevacek]

spray around the intake with brake cleaner, hititng the manifold at the heads, all vacum lines, where throttle body mounts and what not the pressures look pretty good.

something is bleeding pressure off when the engine is off but it does not look to bad over all. I woul dlean towards a vacum leak causeing the lean condition at this point.

 

[RonD]

Fuel pressure at the rail is OK for a 2002 model.
In 1998 Ford dropped the fuel return line from it's EFI system, so 65psi is the average expected pressure, the pressure regulator was also moved to the in tank fuel pump.

Prior to 1998 35psi was the norm, with fuel return line and regulator on fuel rail.