slightly rough idle at low rpm range

[RumpRanger98]

Misfire cylinder #1

seems like my ranger has a rough idle around 1-2.5k but smooths out when it gets higher. I just changed the plugs and wires, new oil, oil filter, new iac, new air filter.

any tips on what it could be?

 

[Beanmachine7000]

It's idling between 1000rpm and 2500rpm? Both those numbers range from a wee bit high (1000rpm) to incredibly high (2500rpm) idle speeds... Check and see if you have a vac line unplugged, or cracked somewhere...

 

[Gillbilly]

or a Possible Throttle Position Sensor problem....

 

[graff104]

Did you try pulling the codes to see if anything is coming up?

 

[RumpRanger98]

Sorry, I mis-said what I meant. From 1k-2.5k rpms the engine revs rough. the idle is at 1k rpm. But when i blip the throttle it revs up kinda rough.

 

[RumpRanger98]

Did you try pulling the codes to see if anything is coming up?

I don't know how to pull the codes, I just got the truck not too long ago. There is no CEL though

 

[Beanmachine7000]

Take it to Autozone or the like and they can pull codes...

 

[betomonroy]

Rough idleing at that RPM range most likly will be caused by a bad Throttle Position Sensor. But to be on the safe side have the codes pulled at your local Autozoo.

 

[RumpRanger98]

so right after I posted it had no cel. I drive it to work and the cel popped on. Going tomorrow morning to have the codes pulled.

Beanmachine, I had said it had no cel and you told me to go pull the codes, Is it possible for there to even be codes to be pulled if there is no cel? i know sometimes things will be bad and wont throw a cel, but does it store a code?

 

[RumpRanger98]

Rough idleing at that RPM range most likly will be caused by a bad Throttle Position Sensor. But to be on the safe side have the codes pulled at your local Autozoo.

candy bar for you if the code comes up TPS ...will post back tomorrow

 

[Beanmachine7000]

so right after I posted it had no cel. I drive it to work and the cel popped on. Going tomorrow morning to have the codes pulled.

Beanmachine, I had said it had no cel and you told me to go pull the codes, Is it possible for there to even be codes to be pulled if there is no cel? i know sometimes things will be bad and wont throw a cel, but does it store a code?

Yeah, it can... They call it a "soft code" on my Camaro, and of course the little scanner anyone can buy won't read those, you have to take it to the dealer (stupid Chevrolet)... I don't think Ford is the same way, though... I think the hand held scanner you can buy will show you all the codes...

 

[RumpRanger98]

so I took it to my cousins shop. code he pulled was misfire from cylinder #1. Its running only on 5 cylinders. I just left it there for him to try to figure out whats going on.

Can you guys give me any tips what it could be? Do injectors go bad on these often? bad ignition coil?

 

[Beanmachine7000]

More than likely not injectors... They usually don't go bad, I'd say it's something to do with ignition...

 

[RumpRanger98]

just put new plugs, new wires on. could a bad TPS cause the misfire on 1 particular cylinder and throw a cel? what other options could it be? and is the ignition coil testable? I watched my cousin use this grounded strap thing and lift the boots on the ignition coil as it was running. and there were sparks.

 

[RumpRanger98]

also whats it take for the misfire code to prompt the CEL? does it turn the cel on immediately when it detects misfire? Because Ive drove the truck about 100 miles or so with no cel.