new to me 1996 explorer from grandma ignition issues , many parts changed

[96eb96]

To Test ECT, KOEO in the morning. IAT should equal ECT within 5 degrees with scan tool. Watch it warm up and monitor the sensors. Come back an hour later, ECT temp should be 10-20 degrees less. Unless you just want to be a parts changer like every other tech. :lol:

yea i will, need to upgrade to post pics i believe. i got borescope down in intake below fuel rail. all the black and brown gunk on sidewalls stops and disappears before the valve. i guess its backside of the valve but it looks clean as far as i can tell with my crappy chinese cell phone scope lol. was reading about injector heat soak with short drive cycles. trying to clean oem injectors. energizing in pulses with cleaner. one def was plugged. also read if one is plugged engine reads lean and trys to overcompensate with other working injectors?

Short drive cycles are brutal on a car, that is considered very severe service. There are places that clean injectors for under $100, and make sure there is a factory spray pattern. I would use top tier gas (Mobil) which has high detergents for a while. Crappy cheap gas can also cause this. Remember this is an old car, cheap gas from 10-20 years ago could have little detergent and cause this. Check your PCV valve too, it can create a dirty intake. Only buy a Ford one, it is quite cheap.

 

[eric mentzer]

Still waiting on fuel rail gasket- refurb injectors look nice. Got my used haynes manual 91 thru 00 explorers wow i like it. Says hot start issues look for vapor lock? What the hell is that? Yes im 33 lol. I looked but didnt see any evap canister on fuel system.

 

[1998Exp]

Still waiting on fuel rail gasket- refurb injectors look nice. Got my used haynes manual 91 thru 00 explorers wow i like it. Says hot start issues look for vapor lock? What the hell is that? Yes im 33 lol. I looked but didnt see any evap canister on fuel system.

There is an evap canister - under the spare tire. However, I don't think it has anything to do with preventing vapor lock.
As far as I know, vapor lock was a concern in carbureted engines with a low-pressure fuel pump positioned far away and above the tank. None of that is true for your fuel-injected 96 with a submerged, high pressure pump in the tank.

 

[96eb96]

Still waiting on fuel rail gasket- refurb injectors look nice. Got my used haynes manual 91 thru 00 explorers wow i like it. Says hot start issues look for vapor lock? What the hell is that? Yes im 33 lol. I looked but didnt see any evap canister on fuel system.

You want this:
Ford / Lincoln / Mercury - Service Repair Workshop Manual 1996-2008 DVD-ROM | eBay

It is worth every penny, believe me. Full wiring diagrams, diagnostics for every code, better repair info. Just verify 1996 explorer coverage with the seller. Has some TSBs you can review as well, they are old but some are helpful.

The Haynes manual is incomplete and has general info. I mean, for some repairs if you are new to the car it may be ok, but anything complex it is not a good resource. If they mention vapor lock it is over :lol:

Also, you want to get a scan tool called Forscan. It covers much more parameters than the OBD tool you have (for example, misfires, EGR, etc). Also covers your ABS, Airbag, 4x4, etc. You can look at misfire counts. You can also do bidirectional (change parameters to test things). You can do tests like turn on your purge solenoid or fuel pump.

You just need a cheap obd-2 adapter (look for BAFX) on Amazon, it is $20. I own it and I know it works well with this setup. Works with many OBD programs. Then download Forscan: Download FORScan, it is free for the PC, a few bucks for the phone. This is a dealer level scan tool, not a toy.

 

[eric mentzer]

Got refurb injectors in and new fuel rail and intake gaskets. Started hot about 20 times over past few hours she lit up every time. No stalls as was expirencing before. Still throwing p1409 egr vac reg circuit. New egr and egr solenoid. Fuel trims changed drastically.
Think could be evap purge switcher or evap solenoid? Def changed from neg to pos trims and started decent but still throwing fault. No road test on trims yet but they damn near zeroed out long term revving to 2500 and short term dropped to 3% at 2500 both long term at 0.0%. Thanks guys

 

[eric mentzer]

Failure to fire just happened again, not sure where to go at this point. Pissed and frustrated lol. All advic welcome short terms fuel trim very high.

 

[Centaurus5.0]

Okay.

I would park it and take a break for a day or two. Try not to even think about it so when you come back you have a clear head and a fresh slate mentally.

Next, please take your time a categorically list everything you've done to the rig so far, listing new parts, used parts, cleaned parts, things inspected, so we are all on the same page. Please don't add what you think it could be at this point, just list what has been done so far.

I searched EF for the P1409 codes as I'm sure you have and it seems the hard starting is a common trait for this code but the OP's didn't report if it was fixed and/or what fixed it.

What you have done so far has not all be for naught as new injectors, O2s and gaskets will make it run that much smoother when fixed.

Too many people with too much experience here for us not to be able to figure this out... but for the moment, just relax.

 

[eric mentzer]

As of today, have replaced fuel filter, plugs, wires, MAF sensor, IAC valve, EGR valve, PCv valve, battery and terminals, egr solenoid, dpfe sensor, intake air sensor, engine temp charge sensor, all 3 o2 sensors, fuel pump relay, fuel injectors, upper plenum and fuel rail gaskets, temporarily tried junk yard PCU computer and nothing changed, cleaned intake thoroughly, fuel pressure regulator (fuel pressure seems fine) although at point of failure I did get bubbles in fuel gauge blowoff tube when I bled the rail, also removed gas cap when wouldn’t start and still failed. Gas tank was in a vacuum once when I removed cap when almost empty still running. Ran a lot of fuel additive through gas tank. Very low mpg, seems to have power on the road when you punch it. Previous owner drove 200 miles a year approximately and always started engine with fuel pedal depressed. Fuel injectors seemed to change obd2 readings the most as other parts didn’t change anything I could see. Cat converter doesn’t sound like liquid is boiling in it anymore after injectors. P1409 egr vac circuit appeared post repairs. Cruise control also is unresponsive. Reset pcu after every attempt at repair. Ford dealer updated pcu. I’m walking away from it now to clear my head haha .

 

[donalds]

Just reading when I got my truck I had similar problems
I tested my coil pack and it was bad
When it gets hot it becomes intermittent
I also recommend testing tps sensor on the throttle body
And clean the throttle body with throttle body cleaner

Do not use break clean or carb cleaner or any thing else

I used throttle body cleaner and a tooth brush

I am by no means a pro mechanic but it's worth looking at and easy to test

 

[eric mentzer]

Researched testing coil pack, saw bottom rust on bottom of pack can affect as their is a mysterious ground attached to mounting plate from wire harness. Coil pack ohmed out uniformly on spark and signal side. Wire brushed and Emory clothed mating surface and added grease **** that comes with spark plug wires. It went from 95% hot start failure rate to a 100% hot start Sucess rate on hot starts. Started great 12/12 times with 30 min delay in between. Cranks for a bit but I did notice prior to this cleaning fuel psi rides at 20 psi till good ignition occurs. Gonna reset pcu and road test tom to see if this improved permanently. Not getting too excited don’t want to jinx it but def a improvement. Still a shaky idle as truck vibrates a tad at idle.

 

[Blk2kXLT]

what a trip, good to read some progress. I did learn that perhaps my lean reading could be related to gunked up fueling. Air, fuel, spark sounds easy

 

[96eb96]

Researched testing coil pack, saw bottom rust on bottom of pack can affect as their is a mysterious ground attached to mounting plate from wire harness. Coil pack ohmed out uniformly on spark and signal side. Wire brushed and Emory clothed mating surface and added grease **** that comes with spark plug wires. It went from 95% hot start failure rate to a 100% hot start Sucess rate on hot starts. Started great 12/12 times with 30 min delay in between. Cranks for a bit but I did notice prior to this cleaning fuel psi rides at 20 psi till good ignition occurs. Gonna reset pcu and road test tom to see if this improved permanently. Not getting too excited don’t want to jinx it but def a improvement. Still a shaky idle as truck vibrates a tad at idle.

Uhh...20PSI is an intermittently dying fuel pump. It should never be at that for more than a second.

 

[eric mentzer]

Yep, new coil pack same ****. Psi with key on engine off was 5 psi even though could hear it running. Even with needle nose jumping relay barely climbed to 20. Intermittent other times it’s 38 once running. No worry’s I’m almost there don’t judge my Hvac hack method. Think like a fox don’t work like an ox lol. My top got screws not the screw ring like I read about.

 

[96eb96]

Yeah, I bet a new pump will solve the problem. Just like A/C diag, all in the pressures!

At least when the evaporator core blows out(yes mine did!) you won't need any advice how to recharge the A/C here

 

[eric mentzer]

Thinks she’s ready to pull got it loaded up with pb blaster waiting on pump. I work on a lot of industrial Hvac **** motors/compressors etc learning automotive is actually really interesting it’s pretty related once you break it all down. Just need to get my hands on it to learn

 

[eric mentzer]

New fuel pump in, road tested all weekend and fired up every time. Actually was easy with access panel cutout. Old pump had rubber check valve on return line. New one didn’t however holds pressure in off cycle. Ford dealer said pump was obsolete had to go aftermarket. Strainer looked ok too. Reused sender no issues. Tank looked clean enough to eat off from visual inspection. Original pump stamped 95 lph 310 Kpa? Interesting. I jumped it to 12 v and it ran but maybe gear/metal vanes that pump in bottom were binding up from age etc.

 

[eric mentzer]

Cut fuel pump apart for ***** and giggles. Vanes are good. Armature is nice, brushes are gone and one spring that pushed the one out is collapsed or stuck non functioning. You can see where brushes used to be sticking out of little metal pieces the springs pushed into armature. Case closed at this point wish I did this repair first. It being intermittent was a pain wish I took amp draws!!!! Before and after and during troubleshooting. Bet they woulda been a flag. Thanks guys

 

[96eb96]

Only way to real diagnose something like that is with a scope and watching the motor current waveform. Even Amp draws don't always tell the story. You could have one bad section, and when it sits on it you don't start (like a roulette wheel) and when it runs you get a regular spike every few milliseconds. Starters commonly fail that way too. Pounding the tank sometimes helps.

I'm surprised the Ford guys couldn't find it. I bet they would have been changing parts just like you did, on your dime. Maybe you can get a job there :lol:.

Also, Once fuel pressure sits at the very low end (like your 27) the pump isn't doing its job anymore. It has some design in it barely function. But the good thing is you learned so much and you will have many, many years with a very reliable vehicle with new parts.

 

[Centaurus5.0]

So glad you found the problem.

Man.. low fuel pressure is a dead give away for a pump with a vehicle that age. Reading though this thread initially, I along with everyone else thought it had been ruled out.

Good call and props to @96eb96.

Now would be a good time run a bottle of this through the tank..

It will permanently lubricate the new pump and injectors with a nano-borate surface treatment. You'll be able to hear a difference in sound with even a new pump.

https://www.energy.gov/sites/prod/files/2014/07/f17/ft018_erdemir_2014_o.pdf

Their oil treatment works wonders as well.

 

[eric mentzer]

Next question guys is I’m still getting a lot of cabin vibrations when idling. Feels like shaking back and forth . Fuel trims are good very low mostly 0.0 is there anything I’m missing or **** it it’s 22 years old drive it till she dies? Muffler is shot can see rust and seams letting loose. Getting flowmaster 40 welded on now that she runs maybe will help. Just wondering about shaky idle. Prob just cosmetic issue now as all reading look good.