2001 Ranger 3.0L Automatic 2WD (not getting past 50mph)

[MikeShepard505]

Hello, I’ll try to keep this short lol. I’m working on a 2001 3.0 for a widow that doesn’t have a single one of her vehicles running. I thought I would be a nice guy and help her out since I virtually brought my 2000 3.0 back to life (almost exactly the same as hers except mine doesn’t have power windows, power mirrors, and hers is a regular cab, and not a flex fuel like mine)
Well she said she was really losing power and it would barely stay on, I scanned the truck and cylinder one was misfiring, visually the clutch fan was absolutely mangled by some “mechanic”, her throttle cable was stretch just from over time, and her air intake hose had a giant rip in it. Well after replacing and fixing what I just said I actually ended up replacing the fan clutch, fan blade, air intake hose, tensioner pulley, serpentine belt, water pump?, replacing her cylinder 1 spark plug wire, and completely flushed and refilled her cooling system. now when I turned the truck back on and got it all back together with new parts the misfire was gone and it just had a really rough idle in park and neutral. I took it for a drive for the first time (because before I worked on it wouldn't stay on more than 2 mins without dying) it would only get up to 50mph. I’m sort of confused. Maybe the Idle air control valve? There was also a little episode my own truck had that was very similar to this after I sprayed down the underbelly of the truck to get all the mud off on it at one point and on the way home on the highway if i let the truck slow down to 70mph it was trying to down shift right in the middle of the highway! Shaking the f*ck out of my truck. Is there something at the transmission or maybe the rear abs speed sensor being wet or dirty that can cause the speed to top out or want to down shift on this 2001? I noticed my truck had mud caked on rear abs speed sensor when it was freaking out and her rear speed sensor is covered in differential fluid for some reason? My transmission had mud all over it too but her underbelly is almost completely clean. Her 2001 has a rev limiter at 3k rpms in park and neutral but my 2000 does not. Please help as I’m at a loss for this lady

 

[MikeShepard505]

Apologies for this book I posted, but I thought I’d share the details for everybody instead of having to explain myself through a bunch of replies.

 

[Dirtman]

The first 2 things that I look for when dealing with an engine that just wont get passed a certain speed is A. A clogged fuel filter, or B. A clogged cat/muffler. Fuel filters are cheap so its worth just replacing it. But a fuel pressure test wouldn't hurt. The exhaust can be checked with a simple vacuum gauge.

 

[Snoranger]

Hello, I’ll try to keep this short lol.

Liar!

I'm with Dirt on this one... if it was misfiring long enough, it could have damaged the cat.

 

[MikeShepard505]

Liar!

I'm with Dirt on this one... if it was misfiring long enough, it could have damaged the cat.

Ohhhhh boy, her ranger had a misfire for a while too and I’m just barely getting to it. She was apparently driving it around for over a month with the misfire. I’m willing to bet it’s the cats

 

[Dirtman]

2 ways to test the cats (well 3 if you have a code for catalyst below threshold)

Hook up a vacuum gauge and rev and hold the throttle at around 2500rpm, the vacuum should drop initially but then rise back up. If it stays low there's an exhaust restriction. Also hit the throttle quick a bunch of times. The vacuum should snap back quickly each time, if it just goes lower and lower each time you have an exhaust restriction.

Second test you need a temp gun. Get the vehicle up to temp and take a reading of the front and back of the cat. The rear should be hotter. If the temps are the same the cat isn't working. (This is an efficiency test, doesn't really say if its clogged it just tells you it's not doing its job).

Like I said previously though, fuel issue can be the problem too. Takes 5 minutes and no tools to change the fuel filter and they only cost 10 bucks. I'd do that before anything if you have no info on when it was last changed (if ever).

 

[MikeShepard505]

2 ways to test the cats (well 3 if you have a code for catalyst below threshold)

Hook up a vacuum gauge and rev and hold the throttle at around 2500rpm, the vacuum should drop initially but then rise back up. If it stays low there's an exhaust restriction. Also hit the throttle quick a bunch of times. The vacuum should snap back quickly each time, if it just goes lower and lower each time you have an exhaust restriction.

Second test you need a temp gun. Get the vehicle up to temp and take a reading of the front and back of the cat. The rear should be hotter. If the temps are the same the cat isn't working. (This is an efficiency test, doesn't really say if its clogged it just tells you it's not doing its job).

Like I said previously though, fuel issue can be the problem too. Takes 5 minutes and no tools to change the fuel filter and they only cost 10 bucks. I'd do that before anything if you have no info on when it was last changed (if ever).

Is it completely normal to be misfiring still but having no codes for a misfire? Engine sputters when I turn her truck on and will die the first time. Takes about 3 tries before it stays on, when the engines cold it has a hard time staying on the idle is way more rough. Seems to idle perfectly fine once it’s warm, but then doesn’t go beyond 50mph

 

[MikeShepard505]

and yes I will go get a vacuum gauge and grab her a fuel filter anyways because her “bf” did some of the work on the truck but can’t give me any direct yes or no answers on what he’s done to it lol I’ll have to check if it’s even in the right firing order, I’m beginning to not listen to what’s “already been done” to the truck because it always seems to be adding to the problems

 

[bobbywalter]

3.0's can go over 50 mph?

 

[Dirtman]

The system that determines a misfire isn't really all that precise to begin with. I've seen the code say misfire on cylinder one but it's actually on two etc etc. It uses the speed of the crankshaft and the crank position sensor, if the crank doesn't speed up when a plug is fired it signals a misfire but as you can imagine this is happening insanely fast so not super precise.

Add to that, the misfire must happen a set amount of times for the PCM to set a code so if the problem clears up quickly enough you will not get a CEL or code.

 

[MikeShepard505]

The system that determines a misfire isn't really all that precise to begin with. I've seen the code say misfire on cylinder one but it's actually on two etc etc. It uses the speed of the crankshaft and the crank position sensor, if the crank doesn't speed up when a plug is fired it signals a misfire but as you can imagine this is happening insanely fast so not super precise.

Add to that, the misfire must happen a set amount of times for the PCM to set a code so if the problem clears up quickly enough you will not get a CEL or code.

Alrighty, I’ll get back to this tomorrow in the afternoon after I’ve messed with the wires and changed the fuel filter. Hopefully progress lol

 

[Snoranger]

3.0's can go over 50 mph?

I really wanted to say the same thing, but he's new here... I was being nice for once.

 

[1990RangerinSK]

3.0's can go over 50 mph?

Yes, they sure can. I routinely drove mine at 70MPH and faster. At 70 in 5th, it had lots of throttle left, and lots of giddyup.

 

[sgtsandman]

Yes, they sure can. I routinely drove mine at 70MPH and faster. At 70 in 5th, it had lots of throttle left, and lots of giddyup.

It's probably in it's power band at that point and ready to jump.

 

[Curious Hound]

3.0's can go over 50 mph?

Mine has hit 80 a few times. Not quite as easy to do with the 35's. But it will do it.