02 ranger 3.0 cuts out at 3,500 rpm's?

[gossler85]

my truck cuts out at 3,500 rpm's almost every time, i can't pull out and get on it or it just like jumps and cuts out, almost like there isn't any power or any fuel getting to it. Please help me! i'm taken off my bed, cleaned out all of the fuel lines and the tank. got a new filter and still freakin doing it. any help would be appreciated. thanks-Ryan

 

[4x4RangerGuy]

Is the ECU popping up any codes?

 

[gossler85]

3.0 edge w/ shitty rev problem

no, not at all. It seems to be perfect, runs great and idles great, just cuts out at 3,500 rpm's. Idk if this has anything to do w/ it, but my truck takes like 10 seconds to start everytime. no matter if it's cold or hot. it takes like 10 seconds to crank over and start. wtf?

 

[almostclueless]

That sounds a lot like potentially bad fuel pump/filter/wiring....should be an obvious first place to check.

 

[gossler85]

i've replaced the pump, the filter, and cleaned out the tank and fuel lines. Any other suggestions. please help. i hate having it take 10 seconds to start and can't run past 70 mgh on the freeway. thanks!

 

[bikerboy]

When was the last tune-up? I would replaced spark plugs, wires, air filter, and clean the throttle body as well as the idle speed motor.

 

[pillen140]

injectors? try dry gas? idk!

 

[J.HYATT]

I've got an '02 automatic that was doing the same thing. Turned out to be a "Transmission Digital Range Sensor" (aka Neutral Safety Switch) that was stuck in the neutral position. I'm not sure if a 5 speed works the same way, but if the computer "thinks" that it's in neutral all the time, the rev limiter will kick in at around 3000, to 3500. That's what it did on mine anyway. The switch was 40 bucks at advance auto parts, took 10 minutes to put on, and it fixed it immediately. See the following link:
http://www.therangerstation.com/forums/showthread.php?t=15871

or just scroll down on the 3.0 forum to the thread entitled: '02 3.0 A/c On = Rough Idle

 

[4x4RangerGuy]

The manual transmission doesn't have a TDRS because it uses the clutch interrupt switch which connects to the master cylinder rod as a "neutral safety" switch. It could be that the switch is bad, and only completing the circuit on occasion.

One thing that 3.0s are famous for is the Idle Air Control Valve (cold start valve) going. I see you haven't replaced that on your list; its possible the IAC valve is not functioning properly and cutting out the motor at that RPM. Additionally, a bad IAC valve will cause the motor to take extra time to start.

 

[almostclueless]

One thing that 3.0s are famous for is the Idle Air Control Valve (cold start valve) going. I see you haven't replaced that on your list; its possible the IAC valve is not functioning properly and cutting out the motor at that RPM. Additionally, a bad IAC valve will cause the motor to take extra time to start.

How exactly is an IAC going to prevent an engine from getting beyond 3500RPM?

 

[4x4RangerGuy]

How exactly is an IAC going to prevent an engine from getting beyond 3500RPM?

I honestly can't explain how, but I've seen it happen on 2 Taurus's I've had at the shop. The motors would just cut out at around 3000-3200 RPMs. I tried diagnosing everything; turned out the IAC valves were bad. Replaced both and the problem went away.

I would guess that since the computer gets a reading from it, if it's not functioning properly at idle then it might be preventing the throttle body from not opening up properly.

 

[almostclueless]

Lotta weird things happen in electrical car stuff.....but I can't even theorize about that one.


BTW to my knowledge the PCM doesn't take any kind of readings directly from the IAC; the PCM reads the idle speed during certain situations and opens/closes it. It's also in the post-MAF path so I don't see how it could prevent high RPM operation.

 

[4x4RangerGuy]

Lotta weird things happen in electrical car stuff.....but I can't even theorize about that one.


BTW to my knowledge the PCM doesn't take any kind of readings directly from the IAC; the PCM reads the idle speed during certain situations and opens/closes it. It's also in the post-MAF path so I don't see how it could prevent high RPM operation.

I always figured the electrical connector was so the ECU could take a reading from the IAC. Who knows, I admit I don't know what really goes on in this specific situation.

I was mostly just offering up a suggestion from my experience.

 

[Bryan22]

check the fuel pressure at the rail and see if you're getting enough, just b/c u replaced the fuel pump dosen't mean it's any good.

 

[Kdawg532]

0i know this was said before but the 5spd auto in my old 04 if it was in park or nuetral it wouldnt rev past 3500 so it is probly what that guy said about the range sensor. its either shorting out or broken sometimes something happens to those and they just keep sending the same codes back to the compy even if nothing is triggering them had a lot of problems with that in my old 99 ranger(not tranny sensor tho ), thats why i went with a manual it dont got one of them things