98 ford ranger won't go over 3000 rpms
 

Hello all,

I need some help with a problem I have been having with my ford ranger. I bought this off my nephew bcuz he needed some money and never drove it due to it being a 5speed and he has a kid and a wife and no room. OK the issue I am having is in gear or neutral I can't get the 2.5 motor over 3000rpms in any gear at all. If you rev the engine up or r driving it when it hits between 2900-3000 rpms the motor acts as if it is going to die and looses all power until you let off the gas. I have replaced the following items on the truck. Oh by the way I have a Cam 2 hand held and there are no codes or warning lights.
All new parts
1) new fuel pump
2) fuel filter
3)new timing belt
4)new motor craft platinum plugs
5) new motor craft plug wires
6)new Mass air flow meter
7) clutch,pressure plate & throw out bearing along with new slave(that needed it replaced others since I was there)
8) exhaust tube behind motor(rotted out)
9) new idle control sensor (acts as elect. Choke)

Truck starts up real quick and idles fine, but when truck is cold the rpms @ 2500 does the same as when it is warm @ 3000 rpms. I even took it to the local ford dealer in my town. Youngstown oh @ Fred martin ford. They told me the wires should be replaced and plugs along with mass air flow valve. If they did it I would have paid over $590.00 total with parts. I bought it all for $230.00 and did it my self and I paid them $95.00 for the diagnoses. I called them after replacing it and told them no difference and the service manager told me to bring it in again and they will look again and it'll be another $95.00. Service manager told me he has never heard of this type of problem and I went to a local garage mentioned it to the lead mechanic. He said that is why he doesn't like fords they are to common in chronic problems and can't be fix without a lot of guess work. I have a Hanes manual and did everything it recommends to no avail.

HELP Please

I have the same problem on one of my race trucks with 4.0l Ford Ranger engine. And I cant figure it out ! Ive replace the ecu the harness and all the sensors. its driving me insane. Due please let me know what u find if you do figure it out.

step 1: remove engine from vehicle
step 2: install carbureted 302 v8
step 3: enjoy a stress free life without ten million sensors and modern garbage that is designed so that YOU CANT WORK ON IT or designed so that IT IS A PAIN FOR YOU TO WORK ON IT
step 4: enjoy a vehicle that is actually now capable of getting out of its own way or climbing up a not so steep hill that your grandmother could climb without even trying.

Sorry bud we tryed the big engine. Truck was slower. Dezert racing! The lighter 4.0 works tons better. Problem is This truck was bought alreaddy built. and has no obd2 port for me to plug into like my other ones. So hard for me to disect whats wrong. Personnaly I perfer new elctronics and sensors. But unfortunatly its kicking my ass for the first time. lol.

I have even disconnect my exhaust from in front of the cat just because I thought maybe it's partially clogged and it still did the same thing. Oh a 302 would be great but then how do I wrk on it. No room to do anything like most of the new cars 1996 and up. URGGHHHHH

It is normal to cut out at 3000rpm in neutral to prevent a no load over rev. But should not do it in a higher gear. If I am not mistaken.

There is a switch that tells the computer whether or not you are in neutral, it is possible that switch is faulty.

You mechanic is a looser, but at least he admitted he is a parts swapper.

You need to look at this from a diagnostics perspective. Ignore the above post about a carbed system being simpler, if you look at FI from the same perspective, FI is far easier to diagnose and repair.

Does the truck have good power under 3500 RPM? If the power is good up to that point, then the fuel delivery and ignition and so forth is probably good, but it it runs crappy and stumbles, then something there is wrong.

There are three basic ingredients to make and engine run correctly, it needs fuel, ignition, and compression. Compression can be ruled out for now because the symtpoms don't match.

You say you have a new pump and filter. Have you tested the fuel pressure to make sure it is within specs? Just because those parts are new doesn't mean that there is not still a fuel delivery problem. The fuel pressure regulator can regulate low, and that cause some issues, but a fuel pressure test will allow you to make sure the pressure is within specs, and that it holds pressure after you turn it off.

Ignition relies on the quality of the parts. You say you went with Motorcraft, good safe choice. There is probably no issue on the ignition side, but don't rule out a faulty Cam Sensor. That sensor provides information used to determine ignition timing. If the timing doesn't advance properly, your power will cut out.

Those systems can be tested, though the Cam Sensor needs a scan tool to look at its waveform.

If you have a major intake leak, like a faulty or disconnected breather tube, the massive leak will adversely affect the MAF readings.

A quick way to see if you have an intake leak or faulty sensors if to have a scan tool and check the Long Term Fuel Trim. If the trim is pretty close to 0%, the fuel management is working fine. But if it is more than ±5%, there is an issue.

Again, if the switch, don't know whats its called, that tells the computer whether or not you are in gear is faulty, the computer will engage a rev limiter like you are in neutral, and you won't be able to go over 3000 RPM.

If it acts like it is going to die, that suggests to me that the fuel pump may not be keeping up, again, look to faulty pump or plugged filter. Don't rule out that the truck may have been vandalized, if someone put something in the gas, it is possible for multiple injectors to be partially plugged. If you put in an aftermarket pump, that could be part of the problem, I learned my lesson about aftermarket fuel pumps.

Great!!
 

Thank you KhanTyranitar,

I will look into the rev limit switch as to the neutral limit. truck has always been garaged and I did put in a ford fuel pump so I hope that will do the job. You know what you are talking about and I will try it out and maybe have to go back to that dealer and se if they can proform the scanes if the limit switch does not work.



:-spam

I've never heard of a 3000 rpm rev limit in neutral. In fact, my factory Ford shop manual calls for using a 4000 rpm engine speed (in neutral) when testing for NVH problems (Noise, Vibration, Harshness).

Check Speed Control Servo. It's in the engine compartment by the heater blower motor, rectangular shape 10 pins in one line.

I think the "Speed Control Servo" is for the cruise control.
I just went out to my Ranger and ran the engine up to 5000 rpm in Park with no missing.

Check for air restriction, maybe a mouse created a nest in the hose.

I'll find out on Monday I hope, I talked with the dealership's owner today and he wants the truck back in the shop. He said his service manager misspoke about not their fault since they didn't do the repairs. So i hope I get a good repair. Also the service manager said the same thing it's for up to 4000rpm's and he doesn't think that is the problem. But can't give me any type of what it could be until it's back in the shop.

My 98 with a 2.5 acted exactly the same way after I forgot to plug in the sensor
on the air intake tube. I think thats the MAF sensor.

limp home?
 

I have the same problem with my 02 4.0 won't rev past 3k. Just started after I did an oil change, filled up with gas and added lucas fuel injector cleaner, am going to change the fuel filter today. Think it could have been the injector cleaner? Bought fuel at the same station for a long time no problems.