Ranger is missing

[john112deere]

My '97 Ranger (2.3, 5-gear, 232.7k miles) has been acting up slightly for a while now. Just a slight miss, every once in a while. It's done it maybe 4 or 5 times now in the last 8-10 months, every time until the last one in steady to heavy rain. Saturday night was the only time it's done it in the dry.

Seems to happen somewhere around 40 mph, and I think I've always been in fourth gear (though I don't know if that's just chance), and it will miss maybe 5-8 times, then it's OK. Often when accelerating up from a slower speed or stop, or shortly after (within maybe 1/2 a mile).

Plugs and wires are 1.5 years old; Autolite plugs and Napa wires. No signs of cracking on the wires or the coil packs.

Maybe it's not logical, but I'm wondering about the fuel pump. (I had the fuel pump fail 2000 miles into a solo road trip in a borrowed car, on I-70 in Denver, at 5:30 pm on a weekday, in 100* weather...) I've also got intermittently poor throttle response off idle, (e.g. when I put my foot back on the gas after upshifting), which improved but did not disappear after cleaning the MAF.

Is a fuel pump reasonable enough that I should pay someone to check the fuel pressure? Buy a gauge? Or should I just replace the plugs and wires and then move on to coil packs?

Thanks!

 

[Bob Ayers]

Has it thrown a CEL? Even if it hasn't, I would get it scanned for codes. Plugs and wires are a good place to start. The hesitation coming off idle could be the TPS (Throttle Position Sensor).

Good luck!!!!

 

[john112deere]

No CEL. I'll have to look around for a place that will scan codes free, AutoZone hasn't made it this far north.

I checked the TPS with an ohm-meter, and it seemed OK- smooth increase (or decrease? I can't remember) as I opened the throttle. Checking the voltage as it was running was beyond me, though- I couldn't figure out how to hook my voltmeter up to it without disconnecting everything.

Thanks!

 

[blacksnapon]

Because its more prevalent in the wet weather, I would start with plugs and wires. Get a spray bottle full of water, adjust it to spray a mist, then while the motor is running, spray water on the plug wires (particularly on the boots). There shouldn't be any spark jumping fire. When replacing wires, always put a dab of dielectric compound inside the boot before installing on the plug.

 

[john112deere]

I did grease the wires when I installed them. I'll get a spray bottle and try that, I guess, once it stops raining...

 

[6L PWR]

The easier way is to just run your tongue along the wires. If it has a bad spot, you'll KNOW in a hurry. ROFLMAO!!

Please note, JOKE, don't really try that!!

 

[john112deere]

Don't worry- even if I was dumb enough to want to try it, even getting your hands near the plugs on a 4-banger Ranger is damn near impossible...

 

[Brian_B]

That spray bottle trick is a good one. Try it at night and if you have a short....its a real pretty light show!

I don't know that this is relevant to your situation, but....

I had to remove my throttle body and clean the back side really well about once a year on my old ranger (89 2.9) once it got to pretty high miles. It would get to running rough, idle bad, and miss (or I thought it was missing) and the gas mileage would go way down. That always cured it for another year or so.

My brother does it about once every six months or so now.

 

[john112deere]

Hmmm.....

Throttle body issues could explain the missing, and funny throttle response. Is there a gasket that needs to be replaced when the TB comes off?

(Gas mileage IS down, but it coincided with putting a cap that's a few inches higher than the cab on, and the switch from summer to winter gas last fall, so I don't think it's representative of a problem.)

 

[Brian_B]

Yes...there is a gasket behind it. I replaced it the first time I pulled it off to clean, but since then I just pop it back on. I think it is about $3 new at the parts store. They have them in stock here.