I'm looking for a good shop in the Denver Metro area for diagnosis of a problem? I have taken the Explorer to Lakewood Fordland, Barbee's Freeway Ford, L&R Automotive (Ford specialists in Arvada) and also AutoFX (Arvada), which not one of these shops were able to diagnose the problem I am having.

1999 Explorer 5.0 AWD w/AT @ 59K miles

I'll try to explain the problem as quick as possible:
Started up the X in July and noticed the engine was running rough, and I could feel a pulse through the brake pedal when applied. About 1 block later the CEL came on, and was diagnosed to be a bad #4 plug. Had all 8 plugs & wires changed out with Motorcraft plugs & wires, and CEL has not come back on. Since that point I've had an intermittent problem I'd describe as: lack of power, loss of power, and rough idle. This problem is most noticable when: driving on any form of incline, between 30-40mph (OD off) or between 40-50mph (OD on), trying to pick up interstate/highway speed, when reaccelerating from slowing down or coasting. I've replaced the: EGR, TPS, IAC, PCV, all 4 O2's, Fuel Filter, Fuel Pressure Regulator, plugs and wires which nothing has helped. The idle runs at about 1200 RPMs when started cold, until it warms up. Which I think is high even when cold, since it never idled this high before the problem. The X doesn't have the push you back in your seat power upon acceleration anymore, this would be the loss of power. Lack of power is when the problem is at it's worst during the above scenerio's. When the speedometer is 30-40mph(od off) or 40-50 (OD on), the RPMs are right around 1500. When the X is around this point, the X stubles every once in a while and the engine sounds like it's bogging down. Also when accelerating sometimes, the RPMs will drop 300-400 instead of climbing. It doesn't drop because it shifts, the RPM's just drop and I feel the power loss through the gas pedal. The Engine tone doesn't sound right, and the exhaust tone is deeper now.

One of the above shops stated the problem was the IAC & fuel pressure regulator. Neither of these items worked. The other three shops stated the X was running at spec. and they couldn't find anything abnormal or off. Please let me know of any thoughts regarding the problem, or of a good shop to check the X out. I'm getting frustrated since I've paid $400 in diagnosis fees and just over $500 in parts, and the X still runs like doo. Thanks for the help in advance everyone!

 

Check your battery voltage and charging system with a digital voltmeter. A few minutes after starting on a cold day you should read at least 14 volts at the battery terminals and no less than 13.5 to 13.8 after it's warmed up and running. Check it several times. Low voltage can cause a lot of unexplained problems.

Has anyone pulled an oxy sensor, stuck a gauge in the hole to read the back pressure of your exhaust system? Plugged catalytic or muffler, perhaps?

Local Auto Zone stores offer a free reading of any codes that might be set in your vehicle.

That's about all I can think of, offhand.

 

You should try posting this query in the Explorer forum. There might be people who know more about technical details of the Explorers on that forum.

https://www.ford-trucks.com/cgi-bin/dcforum/dcboard.cgi?az=list&forum=DCForumID107&conf=DCConf ID9

Good luck.

 

You also may look in the area of the tranny... all of the conditions you described could be attributed to parts in the automatic.

-Kerry

 

Paarrothead - I'll go ahead and check the voltage of my battery, I do think it is a little low. At night with the headlights, foglights and the stock radio on, the lights do go dim sometimes when I'm at a stop light. Both Ford dealers performed cat. efficiency tests, which both came out normal. I don't know exactly what these tests include, but I think it would be all computerized. All of the shops I have taken it to have scanned for codes. Only time I came up with a code was when the CEL was on for the bad #4 plug. Clear ever since.

BubbaF250 - I have had an ongoing post in the Explorer forum, which I have received some excellent advice. Unfortunately nothing suggested has worked.

kspilkinton - I'm starting to believe it is something with the Tranny, since I've found so many problems with the 4R70W. Ford thinks it's okay though. This is why I'm looking for another shop. Ford says thay can't find anything wrong with it, but there is.

Thanks everyone!

 

i have a 91 150 5.0 fuel inj. similar problem replaced throttle possition sensor cured my problem good luck