Cheers, All. I'm a long time reader, life long Ranger lover and first time poster here.

I have a 1998 Ranger XLT 4 x 4 that has been a ridiculously reliable vehicle

In the last year, it started to mildly surge while in park or at idle. And on just a few cold cold mornings the idle would get low (rpm) and throaty and even stalled out. Again, just a few times in the course of the winter

Now just recently (about a week ago) while on a short drive going up hills the RPM started to intermittently but severely drop (as in 2500 to under 1000). It puttered a bit then ran fine, then puttered, etc. I found that if I drove with the rpm under 2K it mostly stayed at bay and let me drive home, then later down to my local mechanic.

Local mechanic had trouble repeating it at first but I asked him to not hesitate and take it for a drive and push the RPMs up...he did and it repeated and he says he thought it was when the car warmed up is when it was likely to happen. (kinda true but then again its done it from cold at times as well). His diagnosis was that I needed to take it to the dealer and have it reprogrammed. NOTE: Mass Airflow sensor is original to the car but clean/has been cleaned with proper cleaner. Vacuum lines also tested fine/no leaks.

Here's where it gets interesting...

Back in my driveway now waiting for an appointment with my dealer (10 days away is their soonest opening and $110 for the privilege of having them look at it) I gleaned some tips online about resetting the PCM myself and having it retrain itself. So...I pulled the battery terminals, grounded and drained it. Low and behold...check engine light went off and it went through a rough period that became suddenly and increasingly smooth on about a dozen starts sitting in my driveway over 2 days this weekend. Smoother than it's run in years!

So last night I took it for a 1 mile loop around my neighborhood...smooth...wonderful...great...again, like it hasnt run in years and no RPM dips like Ive seen in a similar distance the last week or so.

Then...I started the truck again and drove it 1.1 miles down to the gas station to fill up where it died hard and fast as I pulled into the station! I tried restarting it several times: it would absolutely turn over and start strong each time and promptly cut out. Red "Theft" light on ;-)

While waiting for a tow truck to drag me back to my house I scanned the web and found a post with heavy feedback (saying it worked) suggesting I turn the key, shift to drive and back, and that would override the theft fault and let me start up...and it did! I drove home

But the check engine light it back on and it is riding as rough as it was at the start of the problem. lol

Soooooo...I can have a smooth running truck that can only be driven less than one mile (joking), or...?

I like the challenge of learning repairing...I've also had a hard year and really could use the savings of a DIY repair if possible.

Anyone with advice to try other than towing this to the dealer in 10 days?

With kind regards, Anthony

 

Welcome to the forum

1999 was first year Ranger V6 models got PATS, Explorers got it in 1998

There were Ford Alarm systems, but they flashed lights and horn, also had anti-theft light on dash

PATS is only used during startup, once engine is running it is disabled.
PATS leaves fuel system off until PATS key ID is checked, so there would be no startup at all, no short run time.
It is possible late a 1998 Ranger got PATS, PATS keys all have the black plastic handle that contains the RFID tag, if you have any keys that are all metal and they worked then you don't have PATS

Reads like fuel filter is plugged up or fuel pump is failing

 

kind thanks for the advise/info, my friend

I have just one key, but it is a black handle...yet the mfg date for my '98 is Feb. I'll see if I can get an all metal key made just to have a second and eliminate a variable.

Ironically, days before things went screwy I bought a fuel filter but didn't change it because 1) havent done that myself yet (lol) and 2) I have wicked tendinitis flaring up in both elbows and one wrist. Just put it off but I will get a buddy to help and check that variable off too.

Will price a fuel pump next and read up on swapping that out. I love my truck and am happy to try the things I can afford if only in the name of extending the trucks life

 

With Ford Rangers the fuel pump will come on for 2 seconds each time key is turned on, but only for 2 seconds.
They are not quiet, if you are listening you can hear the HUMMMMM, in the cab coming from the gas tank.
So turn key on and off as much as needed, can't hurt anything, and make sure you hear the pump coming on.

PATS disables fuel pump and fuel injectors, if wrong key, or no key is used

 

huge thanks my friend...will do