1996 Ford Explorer many issues that don't seem related.

[carnifex]

I had made a post about this previously, and the weather turned really cold and wet for a long time...and never had a chance to address it during the holidays and such.

So link to the previous post was made under Stock 1995-2001 Explorers on 11-24-2011:
http://www.explorerforum.com/forums/showthread.php?t=336846

You can read that or not, I am going to give info in this post related to what it has done today and yesterday.

Yesterday, started and ran for awhile, tried to shift into gear and motor died immediately. Went ahead with brake line replacement on rear wheels. After finishing brakes, bled the lines and got the pedal back to normal while car was not running.

Started car again, it started, but the idle seemed too high for what I was used to by noise and looked at the RPM gauge on the dash. It was running closer to 2000 RPMs than 1500 (it's usually around 1500-1600 at a guess).

I revved it up a couple times, and idle dropped down closer to normal but was still running a little fast. When pressing the brake pedal there would be a noticeable change in the RPMs on the gauge and the engine noise would change to a slight pull sound. I felt this was abnormal as I don't recall it ever doing this while sitting in parked.

Shifted it into gear and it died immediately again. To start it again I had to hold the gas pedal to the floor and it would idle a little fast like before. Settle down after revving it at least once, but still run a touch faster than normal. Brake pedal still caused pull.

At this point it was getting pretty late in the day, so stopped by auto parts store to get some ideas on frequent replacements and to get an idea on what to look for on here and the web in general. This yielded two possibilities of the IAC and MAF.....and suggestions that the torque converter in the transmission is not functioning properly.

Today, first thing I did was pull the IAC to check how crudded it up it was. The part was obviously sooted up, and I decided to just replace it. I replaced it with a part from Autozone that was missing the black cap on it, but otherwise had the same shape and orientation of the old one. The primary difference being the old one had the black cap and had NO gasket but rubber rings, where as new had no black cap and called for a gasket.

After replacing the IAC, the truck started up as normal, idle seemed fine more inline with what I remembered. The truck shifted into gear, drove it around a little bit to make sure the brakes seemed right and took it on the road. Got it up to maybe 35 and I could tell it was not shifting properly, I attributed this to the motor needing to learn from being screwed up for the last 2 months and not running properly. It would down shift with too much force and it would sometimes shift a little hard going into third. It felt like the vehicle would if I were doing extremely fast stops or accelerations versus what I was doing (casual stop and go around the block), just way too much kick on the up shift at third gear and way too much coming back down for stops. I didn't think it was a symptom of anything at the time, but throwing it in there just case.

Got it back to the work area, turned it off, popped hood looked inside for any obvious problems and tried to start it again. And it started doing the same thing as above, crank endlessly until you held the gas pedal to the floor. Idle seemed better, more normal but it still wasn't right...just a touch too fast. Wouldn't shift into gear without dieing.

Now I will note that my vehicle has had a hesitation at times when giving it gas and it did it a lot throughout this, but it didn't do it even once when I put that replacement IAC on during the first run and drive. And then it started doing it again.

So I tried cleaning the MAF, the MAF looked pretty clean, but cleaned it via directions on this website.....the motor stunk pretty bad after the cleaning for a bit but it made no obvious change in the performance of the vehicle. In fact it might have made the vehicle run a little more poorly after holding the pedal to the floor to start it, it would stutter and shudder for a bit until going into it's a little too fast idle.

At this point I tried cleaning the old IAC and putting it on, the idle went back to obviously too fast..even more pronounced before. Hovering at 2000 RPM instead of just under it like the day before (both are too fast based on past experience).

So right now I think the IAC makes a difference when changed, but I think the part I got might not have been 100% suitable despite matching on the parts store look up. I will be looking into an OEM from dealers to see if there's a possibility there for a better match up.

But I still have an obvious problem with the vehicle not wanting to start without the pedal to the floor.......after it's started once during the day. It seems like flooding, but could be heat related or even moisture related (heat of motor making something take on moisture).

I think that's covered everything I've noticed. I don't think it's the transmission simply because the motor won't start without the gas pedal down, it says something is wrong on the motor side to begin with at least.

Now a couple things to note for the history of this vehicle that I think pertain to this. It has been using more fuel than normal for awhile, I've been putting off trying to fix it until I could narrow it down. I don't drive enough for it to really hurt me on fuel costs, and I have been unemployed for sometime so I didn't want to get into part replacement without having more of an idea of the issue. And it has shown a persistent error on a oxygen sensor that has caused the check engine light to come on multiple times, I think this sensor has actually changed between resetting the codes but I can't say for sure.

So I think I need an IAC, but unless it's a miracle cure I think I have at least one other problem part. Unless the MAF is just outright dead and can do this as a result, it's clean enough that it shouldn't have caused any issues related to it being dirty before or after the cleaning I gave it.



Any ideas are welcome.... Please.


Thanks.

 

[carnifex]

Spent some time again on the truck today.

Replaced IAC and a part that's like a regulator valve for the heating system.....it was leaking. I've had to replace this part twice now, original, replacement #1, replacement #2, and now Im using replacement #3 which leaked right away. So Ill have to replace it again.

I also unhooked battery for 30-45 minutes while I ran to get parts and hooked it back up after I was done putting in the new parts.

Result after doing this was that the vehicle started up without any special effort being made, like it had when running properly in the past. I shifted it into reverse, engine sputtered and died within a few seconds.

I cranked it to start it back up, nothing. Held pedal to floor and it started and ran rough for a bit. Acts like it's flooded. Once it got running normally and smoothly, I shifted it into drive and motor died.


Im just randomly searching for hits on google that might match up with my symptoms. Thinking it may be electrical related, causing many sensors to not function.

The only code I've ever pulled off the vehicle was related to oxygen sensors, and none of those searches seems to indicate that it would cause the issues Im seeing. I am unable to get more codes until I can get it to a somewhat drivable state.

Really hoping someone will read this and have an idea...right now I have possibilities being:

Fuel Pump pressure being too low - but it idles indefinitely just fine...hestitates but can be revved up and held without dieing.

Fuel filter - It might need changed, but the engine is flooding...which doesn't seem like a fuel filter issue.

Fuel Return issue - Maybe, it does start on the first try when it's sat for a long time, but won't start on second try without flooring the gas pedal. But would this cause it being unable to shift into gear?

Transmission problem related to sensors/electronics - I was able to drive it around the block last time I worked on it, then it started acting up again. It will shift into reverse and drive but motor dies instantly 95% of the time, the rest of the time it stutters them dies...and only one time it's stayed running where I could drive it.


Can't afford to keep swapping parts around, especially when I don't have a better idea of what Im looking for as the culprit.

 

[carnifex]

Any suggestions at all for possible components? Or similar problems people have solved? I've been through the threads on as much as I could think up but have not found anything that sounds quite right symptom wise.

 

[carnifex]

Continuing to look for possible problems.

If anyone is bothering to read this, can you tell me if there is an electric module, relay, or fuse(s) that would cause something like this?

I haven't had much luck in tieing the symptoms together into any one thing, and the things that come up have multiple suggested solutions that don't seem to quite fit my issues.

 

[carnifex]

Still looking for suggestions, weather is nasty out, so Im finding less and less good weather to spend time on it and need to be a little more productive with my time.

Please.

 

[DaExplorer]

Don't know why no one has given any thoughts since you started back at Thanksgiving.

A few years ago my son and I had picked up a 94 Exp dirt cheep to use for parts for his Exp. It ran like crap and made lots of noise. Didn't make it home and had to be towed ther rest of the way. Anyway, after my son got the parts he wanted, we decided to see if we could fix it. Long story, great learning lesson for my son. Anyway got it running but would stall when put into gear, Kind of sounds like yours, and couldn't run until it sat overnight. It had lots of issued but turned out that most issues were related to vacuum lines and sensors. Spent weeks on this (before I knew about this Forum) I think the last one was the ERG vacuum regulator EVR solenoid, located on the left side of the engine. The valve was all plugged up. Anyway got it running, passed smog, drove it for a few months and then sold it for a nice profit which we split.



First off reading your post that you replaced the IAC and it didn't have the black plastic cap. It pulls off and snaps back in, so just pull it off the old one and plug it into the new one.


I would re check all the Vacuum lines for leaks or even blockages. Including all the sensors attached to vac lines

Check the Throttle position sensor

Clean the IAT Sensor located on the air intake tube between the MAF and throttle body.

Anyway just my thoughts as to where I would start looking.
Good luck and keep us posted.

Oh... what codes did you get? I know you said something about O2 sensor. If you get any codes let us know what they are.

 

[carnifex]

Don't know why no one has given any thoughts since you started back at Thanksgiving.

A few years ago my son and I had picked up a 94 Exp dirt cheep to use for parts for his Exp. It ran like crap and made lots of noise. Didn't make it home and had to be towed ther rest of the way. Anyway, after my son got the parts he wanted, we decided to see if we could fix it. Long story, great learning lesson for my son. Anyway got it running but would stall when put into gear, Kind of sounds like yours, and couldn't run until it sat overnight. It had lots of issued but turned out that most issues were related to vacuum lines and sensors. Spent weeks on this (before I knew about this Forum) I think the last one was the ERG vacuum regulator EVR solenoid, located on the left side of the engine. The valve was all plugged up. Anyway got it running, passed smog, drove it for a few months and then sold it for a nice profit which we split.

When you say left side of engine do you mean driver's side (looking out from inside vehicle) or passenger side (looking at the vehicle from the front)? I'll have to look it up and compare it, it's been miserable weather lately, snow and ice and now it's raining....and no indoor building to work on it in.

First off reading your post that you replaced the IAC and it didn't have the black plastic cap. It pulls off and snaps back in, so just pull it off the old one and plug it into the new one.

The IAC I replaced it with has a sealed off silver piece where the black cap used to be, there's no vent/exhaust/access port there at all, it's sealed.

I would re check all the Vacuum lines for leaks or even blockages. Including all the sensors attached to vac lines

Im assuming there's a tool for this, which I don't have. But I've pulled off lines and felt around trying to find rough spots or wear spots as best I could. Can't lay on the ground anymore without soaking through the clothes or freezing to the ground.

Check the Throttle position sensor

Is there anything you can comment on here that would be indicative of a problem aside from sensor reports? I don't have the tech gear to check it's voltages and such, but I removed it and it didn't appear gummed up. The motor also didn't react when I had it unplugged or plugged in during start or idling, or help with the shifting into gear. So I had written it off as probably not the culprit due to that.

Clean the IAT Sensor located on the air intake tube between the MAF and throttle body.

This is the little red looking sensor that pulls out easily? If so I cleaned it at the same time I took the MAF out and cleaned it.

Anyway just my thoughts as to where I would start looking.
Good luck and keep us posted.

Oh... what codes did you get? I know you said something about O2 sensor. If you get any codes let us know what they are.

Since I couldn't take it somewhere to get the codes scanned due to it's problems, I didn't have the latest code pull from it before I reset it. I pulled the battery cable off to see if it would reset whatever was giving me headaches, or at least make it act differently. Experienced no noticeable change in behavior.

Was able to start it, let it idle for a few minutes, put it into drive and back multiple times with no problems. Drove it around in a circle, put it in park and then tried to shift it back into drive and it the motor stalled. Then did it's hard to start routine. This when I tried pulling the plug off the throttle control and what not, but hands were getting too numb to keep at it and can't wear gloves and still get those wires off heh.

So.....Im not much further along than I was. But I will look into ERG and see if that adds up to something for me.

Thank you for responding.

 

[DaExplorer]

When talking about cars the side is while facing forward. So left is the drivers side, unless you have a uk vehicle.
I think they gave you the wrong iac.

 

[carnifex]

When talking about cars the side is while facing forward. So left is the drivers side, unless you have a uk vehicle.
I think they gave you the wrong iac.

Went to 3 different parts stores and looked them up online. Aside from the dealer possibly having one with the black cap on it, all of them were sealed off.

The 1995 looked like it, black cap and all but the plug style was different.

They had two different styles for the 1996, one was oriented the same way with the silver cap and plug in the right location. The other had a black cap, but the body was all twisted around and plug came out at a completely different location and angle.

IAC took the idle back down although still a little high especially when the motor has exhibited the no-start without holding pedal to floor issue, but didn't solve the engine not starting when warm or motor dieing when shifted into gear except when left to sit for long periods (and even them sometimes it won't shift without dieing).


But I looked into the EGR, ERG, and DPFE. It sounds like there could be something there simply because of one line I read while reading about how to test them. There is a line I found that said you couldn't thoroughly test a specific part of it without the engine being at operating temperature because the PCM won't turn the EGR system on until it is. If this isn't the cause of it, this could be an explanation why the vehicle won't start properly when the engine has been ran for a bit. It may even explain the shifting issue since it has never shifted on a warm motor (just dies) but has shifted on a cold motor (first start after sitting for long periods).

It's kind of a long shot, but I am going to remove the EGR and clean it to see if it does anything at all. At the moment Im leaning toward it being an electrical problem, but it's hard to say if it's an electrical problem due to a hardware malfunction or just all electronic error with how tied together everything else.

 

[carnifex]

New update to this....

Replaced EGR, no noticeable change.

Began looking for vacuum lines again and found nothing of note. Tried unhooking sensors to see if anything created any sort of change to the engine....nothing.

Had the intake air unhooked at the throttle, tried starting it and noticed the motor changed it's usual problems. Found that letting the intake partially cover the throttle air intake (not seated completely on it) the motor would start a little easier (without holding to floor).

Checked intake hose for cracks, couldn't find any. Started looking at throttle position sensor as culprit. Took it off and reseated it. Something audibly clicked on the second start and the vehicle began operating more like it should. RPMs on motor dropped below 1000 for the first time at idle once it had ran for a bit, it would shift into gear and back into park without dieing.

Now this fix didn't last, but I thought it indicated a bad TPS sensor at least in some aspect of it's functionality. Even the audible click happened again and problems began again.

Replaced TPS with a new TPS and the vehicle had a major issue starting, had to hold it to the floor and it smelled like pure fuel for a long time once it started. After a couple shutdowns and starts the idle dropped down below 1k again and it would shift without dieing. It also started without holding it to the floor and didn't run rough at the beginning like it normally did on a bad start the previous time.

Also while replacing the TPS I replaced a heat exchange valve that had been a major nuisance for awhile, I had to get parts from another store because Auto Zone couldn't supply with me a valve that wouldn't leak within days of replacement. The last one leaked the very first time I put it on.

Now, the heat exchange seems to be working properly but I wanted to let it be known it was replaced because of something I started noticing that weren't something I noticed when the vehicle ran "normally" prior to this mess.

Besides the initial problems with the new TPS, I tried resetting the battery to see if it would repeat the process....and it did. The car would not start without holding the pedal to the floor and it smelled strongly of fuel, after some time running and a couple starts the motor would drop down below 1k RPM and stay running once shifted. HOWEVER..

After I let the vehicle cool down, the motor had warmed up to operating temperature prior to this.......I gave it maybe 15-20 minutes of cooldown to see if I could trust it after it had sat for a bit. The vehicle would not start on normal crank. I had to hold it to the floor to get it to start, strong smells of fuel and exhaust for awhile. The RPMs wouldn't drop below 1800-2k even after revving it. Dies on shifting into gear.

SOMETIMES it would start back up normally, other times it would need to be held to the floor. But one or two restarts and the motor vehicle would function as close to "normal" as I've seen. The motor would drop to 1k RPM or lower on idle, shift into reverse and drive smoothly. I did notice that it would sometimes not shift into 2 and would never shift into 1....linkage issue for sure but noting it in case it is important. I also noticed that the temp gauge on the instrument panel would go from mid range to quarter way up from completely cold repeatedly. This may be attributed to the heat exchange valve working or may be another symptom, I did not notice this during normal operating of the vehicle prior to these problems...the temp gauge never dropped that noticeably. It would fluctuate between slightly above mid gauge to slightly below midgauge once it got to mid level temp.


So, Im as close to normal as I've been since November when this stuff started and it came on abruptly. Prior to this there were fuel mileage issues, probably attributeable to the TPS since it seems to have made the most difference once it was replaced. Im actually seeing major changes in the way the vehicle is responding now versus a very minor change with the IAC and no noticeable change with the EGR. That is not to say the EGR did not need replacing, but it didn't change the vehicle operation in a way I noticed after replacing.

I have gotten check engine lights within the first few starts after battery resets now, but I don't trust the vehicle enough to drive it somewhere to pull the codes at this time. Im going to let it sit overnight and see what happens tomorrow, if it seems I can get it to the shop and back without needing a tow I may have some codes tomorrow. Or perhaps I can borrow a scanner from Autozone for some money down...I'll check into it.

I also can't risk driving it too much because it has a busted exhaust bracket that needs replaced at a muffler shop...probably due to getting it towed. So once Im confident in it's reliability, Im going to have that fixed so I dont end up with more repairs needed.


Right now Im looking at a problem that only crops up on engine start and seems to be evident after a battery reset for at least 2 starts. Once the engine is started and running normally, it seems to continue to run normally (tested this up to 25-30 minutes). If it idles fast, it continues to idle fast and not shift into gear without dieing.

So any input would be great. At least now I've made some noticeable progress that can now maybe lead to some narrowing down of the problem.

I can say it's idled lower today that it has in a long time, but that unreliable start and it causing issues with getting it out of park is making it too risky to drive for my taste.

Other things I noticed prior that persist when it starts "in non normal" state. The motor will hesitate at first when giving it gas, a second hesitation until it catches up. And the RPMs take forever to drop back down once revved in comparison to when the vehicle is operating "normally". It's very very gradual from 3500-4000 for it to drop back down to 1800-2k idle (non-normal) operation. And when the idle is like 800-1200 range it'll go from 3500-4000 range to 1000 in about half the time it goes from 4k to 2k in non-normal.


I don't think it's a transmission issue, the vehicle wouldn't be experiencing the starting and idle issues if it were transmission related IMO.

So Im left wondering if it's MAF, temperature control related, fuel related..etc.

I will say that the vehicle probably has a bad plug or wire because it runs a little rough even in "normal" but I don't see it affecting the idle and such like that off and on.

 

[carnifex]

Alrighty......after working on the vehicle again today I THINK it's fixed. If it doesn't act up or have any issues a week from now, it's definitely fixed.

So Im going to do a quick summary since it bugs me when people drop off the face of the earth instead of posting back here when their problem has been solved.


In total I spent less than 200 dollars. Worked on it probably 5-6 separate days when weather permitted. Would have definitely been solved faster if it weren't the middle of winter when all this happened.

Read above for problems I was having and more details.

The order I replaced parts in:

IAC - 1 year warranty could not find a lifetime warranty one. 40 bucks.

At the time I replaced this I also cleaned the MAF. I noticed no change from the MAF cleaning, it was pretty clean to begin. The IAC made my idle drop some, but overall no real noticeable change. However I do think if I had replaced this later, I would have noticed more change but other issues were taking over.

EGR - Lifetime - 40-45 bucks - No real noticeable change after this was replaced. But the EGR on it had been on for over 10 years, so it was just a matter of time if it wasn't bad already. I probably could have did without this replacement.

Throttle Position Sensor - Lifetime - 32 bucks - This made a very large difference. However there was still some issues with the vehicle not starting after being shut off and left to cool for 20-30 minutes. It was not reliable enough to risk calling it fixed after this. I would say this solved 45% of the problems. It caused the issues to go from being persistent to intermittent.

Air Temp Sender - Lifetime - 16 bucks - This made a little difference. It caused the vehicle to report codes faster after it's replacement. And it solved some of the intermittent issues but nothing major. It was probably on the verge of being past any tolerances it might have for wear and tear.

Engine coolant temp sensor - lifetime - 22 bucks - This solved the rest of the issues. The engine responded predictably after clearing it's memory by disconnecting the battery. It's idle was consistent even after shutting it down to cool off. The power of acceleration was increased noticeably. The motor dropped it's RPMs down in line with how it should versus a very slow RPM decline after hitting 3k RPM or so. The shifting was smoother, not perfect yet but the computer is probably still learning since it's only been a few hours. It's ran better than it has in a long time.

Now, I probably neat an engine tune-up but it's a very minor engine roughness and I'm going to let the vehicle stay as it is for a week or two before I even think about doing a tune-up. I want to see what kind of gas mileage changes I get and see how it behaves. If I don't come back to report otherwise...I'd say the above parts fixed my issues.

If I had to do it over again, I'd clean the MAF and IAC to see if there were noticeable changes. Then I'd replace ECT and TPS since they are are lifetime and cheap....fairly easy to replace. Then I'd probably do Air Temp Sender near the MAF, cheap part with lifetime warranty. Then EGR. Then IAC, and then MAF. My thinking on IAC and MAF is if the cleaning didn't show noticeable changes they are either so far gone nothing will fix them or they are working perfectly. So if you get through all the other cheap lifetime parts and end up back at the IAC, EGR, MAF potentials....do the lifetime parts first and then the IAC since it's 1 year. Not sure what warranty on MAF was.

Assuming you are intending to keep the vehicle...200 bucks in parts to make it run better than it has in a long time is worth it to me. Plus I should be seeing 2-3 MPG minimum increase is my estimate. I dropped the idle RPM from around 1800 to 2000 to around 800-900, increased acceleration power, ease of start... I think it'll bear out in a 2+ MPG gain over the 13-14 I was getting just prior to this whole thing happening. If it hadn't happened I probably would have never figured out the issues since it was so many different components causing similar issues.