anyone have the same problem???

[chris1005]

I own a 1994 explorer4x4,

Here is the problems....engine light comes on when I am at 55 mph and i accelerate. The engine also pings. I also have a miss when I first start to accelerate from a dead stop...this is what I have done so far, new plugs, wires checked and good, new fuel filter, both o2 sensors changed, (are there more than 2?)any more ideas?????????????

 

[aldive]

You really need to determine what trouble code is triggering the CEL.

Good luck.....

 

[MrShorty]

Start with the EEC-IV self-tests to see what problems the computer can see. That will point you in the right direction. An easy to read description of the KOEO test using only a paper clip/jumper wire can be found under code retrieval at www.fordfuelinjection.com complete instructions for both the KOEO and KOER tests can be had at www.dalidesign.com/hbook/eectest.html
A couple of notes:
1) Always troubleshoot codes in the order KOEO hard faults, KOER codes, then and only then move on to the continuous memory codes. Because of the parts you've already replaced, it might also be wise before dealing with the continuous memory codes to clear those codes and see which one(s) come back.

 

[Jason94sport]

Could also be a dirty MAS air sensor. It's easy to clean. Do a search on it. That's a common problem that has those symptons.

 

[chris1005]

thanks for the help guys, but I still have one question, How many o2 sensors do I have on this Veh.?

 

[jever]

there are 2 o2 sensors, one is easy to get to. the other is slightly tricky. i would try retorquing your intake manifold bolts and see if that helps the ping.

 

[410Fortune]

Yes I agree, sounds like the lower intake gasket or the manifold itself is loose.

However anytime you ever get a CEL check the codes, 90% of the time they are true.

However in this case it may not be, you see if the intake is leaking, its sucking in air, and that will cause it to run lean, the 02 sensor will say "hey trucks running lean" then the computer says to you with a code "02 sensor is lean" You replace sensors only to find out the same thing happens with new sensors.......

 

[chris1005]

I think I found the problem, Yesterday I had the tubing off from the mass flow sensor to the throttle body, I was spraying carb cleaner in the throttle body to clean the butterfly area. I started the truck and could not believe the difference in reaction. I took it for a short ride with it all disconnected and it ran 50% better, Does this mean that the mass flow sensor is bad or is it the computer???????

 

[MrShorty]

What codes did the computer give you?

 

[chris1005]

Mr Shorty,

The code was for an o2 sensor was 181, It also had a overheating code which I had fixed by replacing the thermostat.

 

[mjkunz]

I had a similar problem and the solution was to cleas the MAF. Like you said, what a difference. The fillament in the MAF on mine was covered with black build-up. That was the easient fix I've had with my explorer. 94' xlt 4.0

 

[MrShorty]

Was the continuous memory 181 the only code present? Did it pass the KOER test?
181 indicates that the O2 sensor is indicating lean and the computer can't compensate. The ping could suggest that the engine really is running lean rather than getting faulty data from the O2 sensor. Next things I would do:
1) Make sure it passes the KOER test.
2) Check the wiring between the suspect O2 sensor and the computer. Check the ground connection between the computer and the battery. Even though the lean code might be real, we don't want to overlook a simple electrical malfunction.
3) Check the fuel pressure
4) Clean the MAF as suggested. Cheap and easy and might be contributing to the problem.
5) Clear keep alive memory and continuous memory codes, test drive the truck, then run the self-tests and see what, if anything, has changed.

 

[chris1005]

MJ Kunz,

what exactly are you calling the fillament, is this the grid screen that the air flows through, or is it something else?

 

[MrShorty]

The filament is something else, though if that screen is dirty it wouldn't hurt to clean it. The filaments are inside the housing. You have to remove the little black box on top of the MAF. Security torx bits can be found at most any good parts store/tool store. Inside you'll find what looks kind of like two light bulb filaments. those are what need to be carefully cleaned.

 

[chris1005]

thank you Mr Shorty, I will be cleaning these filaments tonight and will let you know, The plan is to use carb. cleaner, is that ok?

 

[MrShorty]

Carb cleaner's probably ok. Personally, I prefer isopropyl alcohol, acetone, or some other solvent that will readily and completely evaporate. You don't want to leave a film behind on the filaments.

 

[chris1005]

well guess what, I had the exact problem that MJKunz had, 1 Q-tip and an ounce of acetone 5 minutes and presto, she runs as good as the day I bought her, I have been trying to figure this out for 10 months, the other day a friend said to try the internet. best words of advice, thank you mr. shorty and MJKunz for your expierence and time.

 

[amystours]

I don't have much of a suggestion for you, but I just bought my Eddie Bauer the other day, and the MAF sensor was unplugged. Apparently, the thing would only go 30 MPH when it was plugged in. For $60 bucks at O'Reilly, we solved that problem, and my CEL is off now. (BTW, there's a core charge on those things!) I am still having an overheating problem, but I think it's something to do with a head gasket, or <gasp> a cracked head....it's blowing white smoke. Also, there seemed to be a little tad of oil inside the air breather tube thingy....not looking too good.