rough idle when cold and at higher rpms

[k9t8m]

Ive got a couple different issues on my 94 that may or may not be related.

Rough idle when cold and at around 5k rpm and above.

At higher rpms during WOT runs it cuts out like crazy like its not getting fuel or something.

Im wondering if it is fuel issue.

Its got newish plugs and wires within the last few thousand miles.

anyone have any suggestions?

 

[brentalan]

How's your fuel pressure?

Cold idle on mine was IAC valve.

 

[GMAN]

Perhaps you have some faulty injectors.

 

[98lincmk7lsc]

Fuel filter?

 

[NoLimit95]

How's your fuel pressure?

Cold idle on mine was IAC valve.

5K rough idle.. Not sure if it would be the IAC. If it was at normal idle, I'd say that's what it would be. Like you mentioned first, fuel pressure tells me the pump may be weak and it might just need some fresh 93 put in and some injector cleaner but a weak pump is my guess.

 

[brentalan]

Yeah, I'm saying there might be a possibility of both the pump and the IAC based on the number of IAC's I've seen bite it on these cars.

 

[zmt325]

try unplugging your maf to see if your high rpm problem clears up.. or just clean it

 

[k9t8m]

Fuel filter?

I bought new plugs and fuel filter yesterday. cheap insurance. Ill probably put them in this weekend.

5K rough idle.. Not sure if it would be the IAC. If it was at normal idle, I'd say that's what it would be. Like you mentioned first, fuel pressure tells me the pump may be weak and it might just need some fresh 93 put in and some injector cleaner but a weak pump is my guess.

I have a feeling its a pump, but we will see what happens after a filter change.

 

[NoLimit95]

I bought new plugs and fuel filter yesterday. cheap insurance. Ill probably put them in this weekend.



I have a feeling its a pump, but we will see what happens after a filter change.

Hopefully it's just the filter. Much easier to swap than a pump and a lot cheaper. Why they ever put the fuel filter where they did is beyond me. They could have put it in a more accessible place to get to it. I need to do mine too. I'm waiting on the new air bag to come in for the passengers side and I'll change it then.

It could also be your FPR too.

 

[ford nut]

How's your fuel pressure?

Check at schrader valve on rail, get a fuel pressure gauge with a long hose, run it up under the hood, hold it in place with the wiper blade.

Check pressure at idle and at WOT.
if it meets specs, I would install a new IAC valve.

Still has miss....

Spray bottle with water on the plug wires.
You spray, it misses, wires are fubar, and or coils, check plugs.

 

[slowmkviii]

I agree with ford nut

 

[k9t8m]

replaced filter last night and although it was the original and needed replaced anyway, it didnt solve my issues. Fuel pressure test next.

 

[2002WRXSTi]

try unplugging your maf to see if your high rpm problem clears up.. or just clean it

I cleaned my maf last night because I had a rough idle. Seems to work but I didn't have the rough at 5000 RPM.

 

[k9t8m]

Checked fuel pressure today and is good. Im gonna seafoam it tonight and clean the mass air tomorrow and put in new plugs. If that doesnt solve anything ill order an IAC.