need help trouble shooting this!

[Stangman Don]

my 96 explorer 4.0L has had an intermiten issue for a year that seems worse when the temp is milder or the truck is hot. It starts just runs rough bogs,backfires etc never smokes though. Sometimes it stalls and wont restart(if you walk away and leave it for 30min it will start up and run perfect). Sometimes when it wont start the power locks will keep locking and unlocking when you are trying to start it. I have done fuel pressure tests,vacuum tests,spark tests all came out good and put close to $600 in sensors tps,crank,o2,map,idle control,maf,coolant temp sensor,egr,mudule,wires,plugs, etc! I have cleaned every + & - contact on the truck as well and checked all relay/fuses/wires for corosion found nothing.
When it is running it runs perfect no issues. When it acts up once you get it running and go 2 truck lenghts it smooths right out and runs great till you shut it off for anywhere from 10min -45min if it sits longer than that it does not act up!

anything that people suggest would be acting up all the time not just once in a while and only if hot and shut off between 10min-1hr any shorter time or longer time than that always starts and runs perfect. Plus if it was something else it would not smooth right out once you drive the truck litterally 2 truck lenghts. (wont smooth out untill you put it in drive and go have tried sitting with it running to get it to smooth out aand did not work have also tried reversing that also did nothing only works in drive) Totally messed up. I have talked to several mechanics ,and ford techs on numerous occassions they are all completely baffled!

 

[Mark_88]

Welcome to TRS...

You might be better to post the symptoms in the 4.0 litre forum if you haven't already done so...I see you've got 7 posts at this time so hopefully you found the forum and the answer...

 

[Stangman Don]

Got no answers yet. New to this computer crap so have no idea how to navigate these sites. That is also the problem with the truck if they had left the computers out of vehicles we would still have good vehicles but since they put computers in vehicles there has not been a GOOD vehicle build as far as I a concerned. I spent 20+ yrs working in Garages and packed it in 7yrs ago due to the computerized junk.

 

[Mark_88]

That is unfortunate about the answer, but it should come...and I know what you mean about computers...that's probably why I'm reluctant to move to fuel injection on mine...

The symptoms indicate a fuel/air issue generally, but I found this information on it so you may want to start by clicking the link below...

http://www.2carpros.com/articles/what-is-an-engine-backfire

This seems to indicate that, depending on where the backfire is coming from, you either have a vacuum leak (check all hoses, especially the PCV valve, and make sure they're connected) or too rich a fuel mixture...

Considering that the symptoms are sporadic (meaning they actually disappear at some point) I would rule out a vacuum leak and focus on the fuel mixture...possibly a fuel pump issue...or a filter that is plugged...but it could be that you may have a sensor issue telling the computer to dump fuel when it doesn't need it...

 

[Stangman Don]

I have replaced the entire PCV system, done several vaccum tests and checked all lines everything is good.have also done fuel pressure check all good. I also tried spraying carb cleaner in the intake once when it would not start and made absolutely no difference still would not fire up! Every sensor is new on the motro and none made the slightest difference! I have spent my entire life working on cars so I know the obvious things to check. Also if it was vaccum it would do it all the time not just once in awhile and only if you drive it for min 30min and it sits for 10min-1 hour even then it only does it sometimes. It starts great cold, if you are only 5min in a store or over 1 hour and about 5 out of 10 times it starts great the rest of the time. never have any issue when it is running you can drive it for hours with not even a stumble.

 

[Mark_88]

Well, sounds like you've just about done everything I could think of (and more)...I would keep an eye on the 4.0 forum...maybe post again if it's slipped down the first board just to keep it near the top...someone is sure to have had the same symptoms...maybe try the search button if you haven't already done so...

Did you try pulling the codes? If you're getting a code it might help diagnose it better...since they OBDII or whatever those engines use is bound to throw something out when it isn't running right...

 

[Stangman Don]

no codes either. I do not know how to find forums. I am not into computers. took me close to an hour to figure out how to post this here and if I did not book mark it I would never be able to find it again.

 

[Mark_88]

Ah, OK...to find the 4.0 forum, just go to the Forums from the main page, and that should show you this forum near the top and the rest are listed below...use the arrows on the side to move the page down and you should see (eventually) the engine forums...

It will be listed as Engine and Transmission...and the V6 forums list all the engines in that class...just click on the 4.0 listing...

To sum up, this page and most others have links to other pages imbedded...so you can navigate simply by clicking on the links...it may take a few tries to get the feel for it, but it really is pretty simple once you see how it works...

When you come into www.therangerstation.com you should see the Forums option right at the top...when you put your mouse pointer on it and click, that is what is called a Link to other pages...

Anyway, if you can find this page you are in the Introduction forum...you can get to the Forums page by clicking at the top where it says The Ranger Station Forums and navigate downward using your mouse...or I will post a link right to the 4.0 forum below...you will see it highlighted when you put your mouse pointer over it...(usually blue) and that means it's a link...when you click on that link it takes you to the other page...

http://www.therangerstation.com/forums/forumdisplay.php?f=67

 

[nightmare596]

I couldn't solve a issue with my s10 so I did a search for sensors and valves on a parts site. Then wrote them all down. Then on my search engine (google) I wrote in egr symptoms for example and it told me exactly what happens when it goes bad. I narrowed it down and only had to buy one sensor.
I know it sounds like a lot of work but now i have a list of what happens when certain sensors and valves go bad.

 

[Stangman Don]

I have replaced all sensors 2-3 times. I started with the obvious stuff . I spaent most of my life working in Garages so know what to look for. As I said Eved FORD DEALER TECHNICIANS are stumped on this and they work on these everyday!

 

[fionablue08]

hello,im new here and im glad to be here.

 

[kimcrwbr1]

no codes either. I do not know how to find forums. I am not into computers. took me close to an hour to figure out how to post this here and if I did not book mark it I would never be able to find it again.

Click on the search and just add key words such as 4.0 stalling I will always remember any key word such as vacuum or PCV and it will give you a list of current posts with that word or phrase.

 

[Stangman Don]

I have checked all Vacuum lines and run a gauge no leaks. That was the first thing I did.

 

[Mark_88]

I have checked all Vacuum lines and run a gauge no leaks. That was the first thing I did.

I think that was just an example of how to use the search engine...

The symptoms you described in your first post are very much like my Tempo had...when the weather warmed up it would bog mostly, and eventually just die....it would start up about five minutes later and run great...

This turned out to be the in-tank fuel pump was going south and replacing it was the only way to get rid of those strange symptoms...it had me baffled the first time it happened, and I actually ended up replacing that pump 3 times over 14 years...

My suspicion was that I would use some Winter gas from one particular station and within that tankful the pump would fail...I didn't use this gas all the time and only when I couldn't find a station that I usually supported (Esso)...

There was something in the Winter gas that was eating the pump seal...again, this was my suspicion...and was never confirmed...

 

[Stangman Don]

mine runs great for hours at a time never bogs while running infact fries the tires at every light if you want to! I have done fuel pressure tests the pump is good.The ONLY time it acts up is if it is shut off for 10minutes to 1 hour after driving for awhile even then only once in awhile! Been doing this for a year. and in that time I have replaced every sensor,the entire EGR system, done numerous fuel and vacuum tests, changed the fuel filter ,flushed the entire fuel system several times, changes the plugs,wires,module, checked and cleaned every ground and every power contact point on the truck had it scaned a few times and even after all that it still does the exact thing it did before I started!! Should have torched it before I spent more in it than it will ever be worth! Now I am totally broke(all my money is tied up in this piece of junk) Cannot afford to replace it and wont get anything for it with it acting like this! STUCK at home as I live in the country and cannot drive anywhere in this (I DO NOT TRUST IT)