1983 - 2012 Ranger & B-Series All Ford Ranger and Mazda B-Series models

Lost for words. P0171

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Old 03-17-2018, 10:20 PM
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Lost for words. P0171

I've been on this sit for years but can't recover because no longer have e-mail address. I bought a 2002 Ranger auto, 2.3 a month ago. It was running a little rough but was I thought fixable. Now $1300 in repairs and still same problem. First shop they changed Intake manifold, fuel cap, coil, plugs, air filter, thermostat. Second shop changed MAF then told me the PCM needed to relearn. After about 100 miles, no change. Went back to them, then told I need a new MAF. I took that out to get the part # and found that it has been changed in the past at sometime with a Cardon one. Contacted the seller and he had it for 2 years and didn't change it. So It is still running bad, stalling, no power, RPM's up and down. I just don't know what to do? Any help.
 
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Old 03-17-2018, 11:33 PM
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Does it have the fuel pressure regulator on the fuel rail ???? If it does remove vac line and see if it is wet with gas or smells like gas,,,just a wild guess,,,,could be wrong
 
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Old 03-18-2018, 09:27 AM
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Welcome to FTE.
Lots of unknowns, so we need some more info to try & help focus your trouble shoot.

How many miles on the vehicle & is All Ford specified scheduled maintenance replacement fluids & parts like PCV valve, fuel filter, air filter, ect been replaced on time with OEM, or parts/fluids that say they meet or exceed Ford specs? For example it sounds like the MAF sensor has been replaced with a reman unit & MAF sensors rarely go bad!!!!

Did all those replaced parts check/test bad?
Is the Snapon scan tool yours, or was that just a screen shot from one of the garage tools? If it's yours, are you turning the wrenches on this repair scenario, or farming the work out?

Have a read here of good suspects for the generic P0171 lean code if your turning the wrenches on this trouble shoot. https://www.obd-codes.com/p0171

On your 2002 Ranger the fuel pressure regulator has been moved to the in tank fuel pump assy.

If fuel pressure, delivery rate over time Don't check out, has the fuel filter ever been replaced?

If all thats ok, has the PCV valve & it's rubber hose or fitting been checked, or replaced?. Since the PCV is down stream of the MAF sensor, If its sticking open or worn & not sealing well, or its rubber fittings leak any air, that leak isn't monitored by the MAF sensor, so could be what amounts to a vacuum leak air source that'll corrupt fuel trim.

If all vacuum lines seem physically ok, no mushy/hard/cracked/dry-rotted/loose fitting vacuum lines, or corrupt PCV valve, or its rubber fittings found. Or no vacuum system leaks found with a home made Swisher Sweets cigar smoke test, blown into a handy disconnected vacuum line, like the brake booster line & since you have a IMRC code, be sure to check the Intake Manifold Runner Control actuator & line for vacuum leaks.

If all that checks out, then maybe dirty/sticking/clogged up fuel injectors need to be put on the suspect list.


If that's ok, have the scan tool take a look at the upstream/before cat O2 sensor switching range & speed. With age they'll get slow to switch & the voltage switching range will be wimpy, kinda like me!!!! lol

Since the MAF sensor seems to have been replaced & they don't usually go bad unless contaminated, what kind of air filter is in the air box? Over oiled cotton gauze & foam type air filters are known to cause MAF sensor contamination & thus corrupt engine intake air flow info to the computer, so can corrupt computer control of fuel trim, SO, OEM paper filters are recommended.
If you suspect the MAF sensor is dirty, remove it, let it cool & spray clean it from both sides with a non residual, plastic safe cleaner, like CRC MAF sensor spray cleaner. Don't touch the sensor with the spray wand & keep it squeaky clean on re-installation.


A bunch more thoughts for consideration, post up more vehicle historical maintenance/repair info & let us know how your trouble shoot goes.
 
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Old 03-18-2018, 10:19 AM
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Thank you for replaying so quick. I forgot to mention that the compression check was all good. And told by the second shop that the fuel pressure was checked and good. I have not turned the wrenches except for removing the PCM. The mileage is 149,000 believe me I have been reading a lot about this. Concerned about replacing the PCM if it has been changed before at some time. The scan tool was from the first shop and I took a picture of it. All codes were cleared, and parts replaced then the P0171 can back. Not sure about past scheduled maintenance replacement. I believe I will try to replace fuel filter and PCV and check again for vacuum leaks again my self. After I R&R the PCM, it seemed to run good at normal throttle for about 5 miles. Thank you guys.
 
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Old 03-18-2018, 10:50 AM
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Ok, good feedback, so did the garage that performed the fuel pressure check give you the Numbers, if so post them up. Did they also do a fuel delivery volume over time test? It should be something like 1/2pt- per15 seconds pump run time. Volume testing can tattle on a wimpy fuel pump, clogged fuel filter, or crimped fuel line. I agree with the mileage & unknown maintenance history, replace the fuel filter & other scheduled maintenance items, to bring the vehicle up to date on All due past & present scheduled maintenance replacement parts & fluids, so to get a solid foundation from which to trouble shoot further needed repairs.
With this kind of mileage, it'll be important to bring All scheduled maintenance items up to date & OEM parts & fluids are recommended, as they're of good quality & fit.
With this kind of mileage, the engine timing belt is past due for replacement & while your in there replace the water pump also.

Good idea to replace the PCV valve & fuel filter, as both of those are way past due for replacement. Check the owner manual, as you might be included in a no cost PCV valve replacement by the Dealer/Ford, as it's Expensive!!!!.

Seeing as how the scan tool isn't yours & you seem to want to perform some trouble shooting, consider investing in the inexpensive ELM scan tool & running FORScan diagnostic software on the viewing device of your choice as discussed here https://www.ford-trucks.com/forums/1...-scantool.html, as it can query All of the vehicle computer/controllers for trouble code clues & help focus a trouble shoot for not much investment. Mine paid for itself on the first use, by focusing & fixing my ABS trouble shoot & finding GEM body codes I didn't know I had, that helped me also find & fix my recent power window woes & at no further cost!!!! That was Sweet!!!!

The IMRC control is vacuum actuated I believe & if so could be a source of a vacuum leak that could corrupt fuel trim lean. With the IMRC acting out, it can also cause driveability problems & there are several Forum threads on it that a search will turn up.
More thoughts for consideration, let us know how the trouble shoot goes.
 
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Old 03-18-2018, 02:10 PM
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The garage did not give me the fuel numbers nor did I ask. Not sure what test they did for that, I'll ask and see what they tell me. I'm going to order the ELM327 scanner to assist me. I'll call the dealer tomorrow to see if the cover the PCV valve. I just watched a video on how to change that. I for got to mention that the seller told and pointed out that he changed the IRMC. it looks brand new. I will be doing the smoke test as well an update any information I find out. Thank You.
 
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Old 03-18-2018, 03:37 PM
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Ok, have a look on this site for TSB's & wiring diagrams that can likely offer up good info on your smoke test & other vehicle trouble shooting. Log in & look in the Tech Info drop down for the TSB & Wiring pictorials.
BBB Industries- Premium Alternators, Starters, Power Steering Products TSB's & Wiring Diagrams

There is a TSB on how to perform a smoke test & what to look for that might be of interest. It's performed with a Rotunda smoke machine, but your machine might be called a "Swishers Sweet" Puffer!!! lol
Be aware you could have a vacuum leak in the cabin heater/AC control panel in the dash, so be sure to have a look & sniff test in cabin, as well as under hood.
 
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Old 03-18-2018, 08:16 PM
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Lots of great information, thank you
 
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Old 03-20-2018, 12:03 PM
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Well Cardone was not much help. this is what I wrote them.I bought a 2002 ford ranger about a month ago and had some work done to it. The garage now tells me The PCM is bad. I removed it to get the part number and noticed it looks like it has been recently changed with one of your units. I took pictures of it and wonder if you can give me more information on it. Your part # is 788560F another # on it is TG5853 and another # is 201607087857578. Is there any warranty on this? I can’t get a hold of the seller to find out when this was changed. My VIN is 1FTYR10D62TA45236Thank You.
Jon Slone
This was there response.

Good morning John,


The only information we would be able to provide would be based on part# 788560F and specifications. We do not sell directly to the public, therefore we would not have any records on the purchase history of this part nor on warranty information as that would come from the point of purchase.





Thank you,

Lisa

Customer Service

Cardone Industries
 
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Old 03-20-2018, 08:24 PM
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I was just looking at the on line 02 Owner Manual, Scheduled Maintenance & Warranty info & it seems for the 02 year Rangers the first PCV valve replacement is no longer on Fords dime, it's now at the owners cost.
 
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Old 03-20-2018, 09:18 PM
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I just read on it's location and the say to remove the wheel and housing and you should be able to get it. that's next. thanks
 
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Old 04-08-2018, 08:52 PM
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Well an update but not fixed yet. I couldn't afford to but I took it to a Ford dealer to check it out. I told them all the work that has been done. They told me they had a 59.99 diagnostic fee, so I figured why not. They had it for 4 days and 500 later said it runs like new. Yea until I left the parking lot at closing time. I have since taking it back once and sat for 5 hours for them to tell me they needed more time. I could not do with out it at the time, so I will be returning again tomorrow. First they said bad MAF. That changed to the first shop routed the vacuum lines wrong after changing the intake manifold. And the upstream O2 sensor was bad. So they were fixed. Still same problem. I'll update.
 
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Old 04-09-2018, 01:55 AM
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Did you ever come by the ELM scan tool & have you had FORScan have a look at all of the vehicle computer/controllers for trouble code clues? If so post up All code Numbers, as they can help focus your trouble shoot.
Also get the trouble code Numbers from the Dealer that you've paid for, thats caused them to perform the parts replacement they've done so far & post those code Numbers too. They should be on their work receipt.
 
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Old 04-09-2018, 07:46 AM
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P1512

The dealer receipt says it read P1512. With that, I have not seen that code before. I’d like to order the ELM scan tool from here, any suggestions? https://www.walmart.com/ip/Hot-Sale-ELM327-Auto-Scanner-Senza-Fili-OBD2-Adattatore-OBDII-ELM-327-Interfaccia-OBD2-OBD-II-Auto-Diagnostica-Scanner-Wifi-Tool/106453754For 11.98 it seems to cheap to be true.
 
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Old 04-09-2018, 10:02 AM
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This looks like a Walmart Vendor. Don't know how legit his product is, so investigate its operational abilities for your choice of viewing device/s & the vehicles you want to use it on & the vendors return policy, closely.
The item says it has an Off switch & works with Windows android, so it seems to be a sorta updated model from mine.
The Disc that comes with them are known to have malware, so scan it for problems before loading or using it, so you don't infect your viewing device.

If your looking for a WiFi ELM, also consider Vender BAFX in my link, as they have a Bluetooth & now have a WiFi model & those on FTE & TCCA that have purchased from them have found their ELM's to work.
They also will work with you if your having problems in setting yours up, or are having operational problems with it after the sale. Don't know anything about the Walmart vendor contacts, or their applications, or problem solving ability. Shop frugal but wisely.

The ELM & running FORScan diagnostic software on the viewing device of your choice is a Very powerful diagnostic combination, so should be able to offer up some more clues for your trouble shoot.

The P1512 DTC = IMRC = Intake Manifold Runner, stuck closed. Maybe that's what the vacuum line was misrouted to?


If you come by the ELM running FORScan, post up All code Numbers it finds.
 


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