<< SOLVED!... P0171 & P0174, FTrims WAY positive, O2 sensors "bouncing" full range!...

[FordTruckinRanger]

Stole this from a youtube video, but I grabbed a small hand transfer pump from harbor freight for less than $5 and a single black 'n mild cigar and made a cheap smoke machine. Worked great, I found a leak at my PCV valve with it.

 

[bills4065]

If you add E85 to let me just say what is regular fuel here- E10.you can mess up the computer fuel map. According to a forum of which I am a member the alcohol content the computer thinks is in the tank can be reset with a scan tool. This person also said he knows people with flex fuel vehicle ,they never put E85 fuel in the vehicle. Just passing on what I have been told. Just a thought, since you have had many different grades of fuel in tank see if there is a way to test the sensor that tells computer the content of ethanol in tank.Never see flex fuel vehicles where I live.

 

[SenorNoob]

Stole this from a youtube video, but I grabbed a small hand transfer pump from harbor freight for less than $5 and a single black 'n mild cigar and made a cheap smoke machine. Worked great, I found a leak at my PCV valve with it.

That's actually genius. And cheap. I love it.

 

[fixizin]

If you add E85 to let me just say what is regular fuel here- E10.you can mess up the computer fuel map. According to a forum of which I am a member the alcohol content the computer thinks is in the tank can be reset with a scan tool. This person also said he knows people with flex fuel vehicle ,they never put E85 fuel in the vehicle. Just passing on what I have been told. Just a thought, since you have had many different grades of fuel in tank see if there is a way to test the sensor that tells computer the content of ethanol in tank.Never see flex fuel vehicles where I live.

Wow, what "forum" is that vague UNsubstantiated info from? I'm trying to "hack" my way deeper into the obscure corners of my klugey mid-1990s OBD-1 AND OBD-2 scan tool, to find the actual Voltage Output of the ethanol sensor, but not there yet. Also need to research if my generation EEC-IV can output specific pulse-width data for the fuel injectors, or if it only derives that internally from the Fuel Trims. (Also not sure why that forum uses terms like "fuel map" or "ethanol in the TANK"... computer only knows--in REAL-TIME--the ethanol % in the line between the fuel filter and the fuel rails, and adjusts on-the-fly...)

However, I do see the computer adjust ignition-timing "BTDC" based on whether I'm running E85 or UNL87, so that sensor is doing something... (Even so-called E85 can be as low as 70% E, so no "mapping" possible, just SENSING...)

As far as "they never put E85 fuel in the vehicle", umm, WTActualFark? Why have a Flex-Fuel vehicle? While we don't enjoy the subsidized LOW E85 prices here on The East Coast that they do in the Midwest, it's still a low-cost way to scavenge ALL the water out of your system, AND clean the injectors, etc... Soon I will buy/rent a Borescope, and when I change out the schmancy "dual-platinum" plugs, I'll take a peak at my pistons and valves for carbon build-up. (Will post pics if possible...)

(recent) True Story--E85 saves the day: in April 2023 we had UNprecedented FLOODING here--Ft. Laud/Hollywood Int'l Airport CLOSED, Port Everglades FUEL Depot OUT OF ACTION! Peeps too young to remember the GAS LINES of 1973 got a big taste of those!... but not me--several stations were out of EVERYthing... EXCEPT E85! "Right this way sir, NO WAITING 4 U!" heh heh heh...

To paraphrase Blue Oyster Cult: "Don't fear the Reaper Ethanol!" ... err, umm, IF you have V-VIN, lol...

 

[bills4065]

"The forum" I am talking about is ScannerDanner premium. Any issues you have with it,take it up with Paul Danner,not me. Have a good one.

 

[fixizin]

No offense, but it sounds like you're PAYING for a forum that's lacking in real-world data... #JustSayin'

Meanwhile, I pulled vacuum on my EGR and it opens and closes normally... off to look for LEAKS.

 

[fixizin]

Stole this from a youtube video, but I grabbed a small hand transfer pump from harbor freight for less than $5 and a single black 'n mild cigar and made a cheap smoke machine. Worked great, I found a leak at my PCV valve with it.View attachment 132334

Hey, just picked up the exact same ChiCom pump from HF... now for the OUTput hose... I assume you disconnect the intake tube from the MAF housing, and... use a rag(?) to fill up the huge diameter difference, then pump in the smoke with the engine OFF...? Help a noob out here...

PS: did you try to use the tire-pump feature of this unit? I could NOT force the Schrader-chuck into that THICK-walled black tube with the TINY Inside Diameter!... silicone?

 

[FordTruckinRanger]

Hey, just picked up the exact same ChiCom pump from HF... now for the OUTput hose... I assume you disconnect the intake tube from the MAF housing, and... use a rag(?) to fill up the huge diameter difference, then pump in the smoke with the engine OFF...? Help a noob out here...

PS: did you try to use the tire-pump feature of this unit? I could NOT force the Schrader-chuck into that THICK-walled black tube with the TINY Inside Diameter!... silicone?

I pulled a vacuum line off by the throttle body and the red silicone hose that came with the pump fit onto it pretty well. Yes, do it with the engine off. I'd send a pic, but my engine is out and torn apart now!

 

[fixizin]

I pulled a vacuum line off by the throttle body and the red silicone hose that came with the pump fit onto it pretty well. Yes, do it with the engine off. I'd send a pic, but my engine is out and torn apart now!

Bragger!... Dang, wish I could pull my engine out, walk all around it, fix every little thing with open access, and not be trying to squeeze into every nook with a tiny mirror and barked knuckles... OTOH, compared to FWD compacts, it's a breeze!

GREAT TIP about the vacuum hose.

 

[fixizin]

OOOo-KAY!... finally did the smoke-test, and NO visible leaks, BUT... that vacuum hose you pull off the driver-side throttle-body is GONE, dry-rotted, just one long slit, open to the atmosphere... that would probably do it, right? Sucking in UNrestricted air WAY downstream of the MAF and even the IAC (which would explain the rough-idle at startup, but smooths out later on, eh?)

I'm YEARS behind replacing each and every VACUUM hose... so many different sizes involved... NAPA here I come. (The one I'm talkin' 'bout here is 5/16" or 8mm...??)

Remind me, WHAT is that device/sensor on the left fender which that vacuum hose connects to??? <<-- D'OH, evap purge valve!

Thanks in advance!

PS: serious overkill, but just found a length of VERY reinforced Goodyear Red heater hose, marked both 3/8" and 10mm... tempting... will size check it...

 

[pjtoledo]

with a cap on it? evap valve?

pics please.

 

[fixizin]

D'OH!... sorry, yes it's the evap purge valve...

So, the 2nd hose from that purge valve, that runs down to the hard metal line, is completely covered by a protective shroud/loom... but it should be the same size, yes/no? Need to replace that at the same time.

 

[fixizin]

ALL-righty then, got some snazzy RED heater hoses 'tween my purge valve and throttle-body suck-point (only TEMPorary, cuz heater hose is NOT fuel-rated, and basically there's gasoline fumes being sucked through there, right?)...

... started COLD engine and Idle is immediately better! LTFTs both down to 21, STFTs down around 0 to -3%, didn't have a chance to drive it around or even warm it up, but I briefly rev'd it to 3,000RPM and IIRC LTFTs dropped to 14-15...?

Wish I had mapped MAF volumes to RPMs earlier... can always pull that hose off and do so... CLEARED the codes, will be in-town driving tomorrow, and see if they recur.

Here's the markings on the old hose... can't believe it only lasted 27 years! The side you can't see is one long slit where it collapsed on itself.

Anyone know what those markings/#s mean?... size? Gauge/thickness?

 

[fixizin]

NICE!... EEC-IV continues to adjust parameters... took an 8-mile toodle 'round town, incl. a couple stretches where I went WOT in 2nd gear...

... NO CEL, LTFTs now down in the mid single-digits (though not so closely matched as before...), STFTs still 0-to-small-neg-#'s

... O2 sensors still 0.88V at both Idle and WOT, but much lower at in-between RPMS...

Just need some RKI advice before I hit the parts store for FUEL (not vacuum) hoses... Hello, is this thing ON?